Beneficial insects, predatory mites and entomopathogenic nematodes: 37 species with their biology and release rates

Savvas Pastopoulos, Agronomist MSc, Pastopoulos Agronomics, Neos Mylotopos, Pella, Greece

Beneficial insects, predatory mites and entomopathogenic nematodes are living organisms released into a crop to eat or to parasitise the pest. They are not plant protection products. They carry no marketing authorisation number, no dose in grams and no pre-harvest interval. What they do have, and what chemical products do not, is a life cycle, and that is what decides whether a release succeeds or fails. When to release, at what temperature, at what humidity, onto which leaf surface and against which stage of the pest all follow from the biology rather than from a label. This article covers thirty-seven species available on the Greek market, with published temperature thresholds, release rates, the Greek legal framework and the documented reasons releases fail.

1. Why they hold no authorisation, and what they hold instead

Regulation (EC) No 1107/2009 defines a substance in Article 3 as a chemical element or compound, and a micro-organism as any microbiological entity including lower fungi and viruses. A predatory mite is neither a chemical compound nor a microbiological entity. The word macro-organism appears nowhere in the Regulation [76]. They fall outside it by definition rather than through an express exclusion, and that is why there is no active substance approval, no authorisation number, no maximum residue level and no pre-harvest interval.

This is where the usual conclusion stops, and this is exactly where it goes wrong. Greece does regulate beneficial macro-organisms, through a separate instrument. Ministerial Decision 10522/117908 of 22 September 2014 establishes a National Catalogue of Plant Protection Preparations containing Macro-organisms, and Article 2(3) expressly prohibits the production, import and placing on the market of any preparation not registered in it. Article 6(1) requires the registration number to be printed on the label, together with the species and the number of individuals [74].

A second filter matters more than the first. Articles 4(1) and 6(3) permit import only for organisms listed either on the National Catalogue of Macro-organisms or on the EPPO list [74]. The Greek catalogue currently holds fifty-three species [75], and the corresponding EPPO instrument is Standard PM 6/3, which lists agents used in the EPPO region with no adverse effects or with acceptable ones [73]. The dual wording has a practical consequence. Franklinothrips vespiformis, for instance, is not on the Greek catalogue but is in Appendix 1 of PM 6/3, so it can be imported lawfully by that second route.

Technical evaluation of applications is carried out by the Biological Control Laboratory of the Benaki Phytopathological Institute, while the competent authority is the Directorate of Plant Produce Protection of the Ministry [74]. The same model, national registration rather than European authorisation, applies with variations across the Union, which is why a preparation lawful in Spain is not automatically lawful in Greece [78].

Nematodes

Entomopathogenic nematodes follow the same logic. A nematode is a multicellular animal and therefore not a microbiological entity under Article 3, and Greece classifies them explicitly as macro-organisms: Heterorhabditis bacteriophora, Steinernema carpocapsae, Steinernema feltiae and Steinernema kraussei each have their own entry on the national catalogue [75]. There is however one real difference. Nematodes obligatorily carry symbiotic bacteria, and for that reason several countries ask for data on the bacterium during registration, which they never do for insects and mites [78].

Organic production

Regulation (EU) 2018/848, Annex II, Part I, point 1.10.1 names protection by natural enemies as the first of the preventive plant protection measures. Point 1.10.2, which refers to the authorisation regime of Article 24, concerns products and substances. A living predator is neither. Releasing beneficial macro-organisms in an organic crop therefore requires no input authorisation and appears on no input list; it is simply a permitted and indeed prioritised cultural measure [77].

Sources: 73 74 75 76 77 78

2. The three modes of action and why the distinction is practical

Dividing the agents into predators, parasitoids and entomopathogenic nematodes is not taxonomic bookkeeping. It determines three things a grower can see in the field: how many pest individuals each agent kills over its lifetime, how long before the result shows, and what exactly needs to be counted to know whether it worked.

Above these three categories sits a fourth distinction, which describes not the organism but the strategy: conserving populations already present, classical introduction of an exotic agent for permanent establishment, and augmentative release of mass-reared individuals [80]. Augmentative biological control now offers more than two hundred commercial species worldwide, and the standing paradox of the field is that actual uptake remains far below availability [79]. Research has not stopped: recent directions concern mass rearing, compatibility between agents, and conservation of populations within the agroecosystem [81].

This article is mainly about the third strategy, with two notable exceptions. Rodolia cardinalis is already established throughout the Mediterranean and is not purchased, while Amblyseius andersoni overwinters in the leaf litter and in perennial crops can be conserved rather than bought again each year [16].

Sources: 16 73 79 80 81 95

3. The selection tool, by crop and by pest

Sources: 2 13 73 90

4. Canopy predatory mites

Phytoseiid mites are the most widely used group of beneficials in the world, and the choice between them rests on a classification published in 1997 that remains the working tool. The species fall into four feeding types [1]. Type I is the specialist spider mite predator, that is Phytoseiulus, which eats nothing else and does not survive without its prey. Type II is selective, preferring spider mites but tolerating pollen. Type III is generalist, taking thrips, whiteflies, eriophyids and pollen, and only this type can be established preventively, before the pest appears. Type IV feeds mainly on pollen and is not represented here.

The practical meaning is simple and not said often enough. A Type I species is curative. It goes in when the spider mite is already present, cleans up, and then dies or leaves. A Type III species is preventive. It goes in first, lives on pollen, and waits. Buying Type I for prevention is money thrown away, and buying Type III to clear an established spider mite focus is time thrown away.

Phytoseiulus persimilis

Phytoseiidae. Predatory mite, spider mite specialist

Spider mites not on tomato

Temperature

Active from 13 to 27 degrees. Above 30 it becomes inactive, that is it stops searching and feeding.

Relative humidity

It requires relative humidity above 70 percent. The requirement is critical rather than merely preferable, because in drier air egg hatch is lost.

Release rate

From 2 to 50 individuals per square metre at each release. The range reflects the intensity of the infestation, from a preventive introduction to a curative intervention on an established focus.

Availability and legal status

Koppert, Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteAt 60 percent relative humidity fewer than 20 percent of eggs hatch, and no commercial strain is more tolerant than any other.

Sources: 3 73

Neoseiulus californicus

Phytoseiidae. Predatory mite, selective on spider mites

Spider mites Eriophyid and tarsonemid mites Thrips, secondary not on tomato

Temperature

Below 10.3 degrees development stops. Above that threshold the cycle from egg to adult requires 86.2 degree-days, that is the accumulated daily degrees in excess of 10.3. At 37.5 no egg hatches.

Relative humidity

It becomes sensitive once relative humidity falls below 60 percent.

Release rate

From 25 to 125 individuals per square metre, in at least five consecutive weekly releases. The repetition is part of the rate, not an optional reinforcement of it.

Availability and legal status

Koppert, Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt survives on pollen and tolerates ten days of starvation without losing fecundity, so it can be released preventively. EPPO accepts only non-diapausing strains.

Sources: 5 73

Neoseiulus cucumeris

Phytoseiidae. Predatory mite, generalist

Thrips Eriophyid and tarsonemid mites Spider mites, secondary Whiteflies, secondary not on tomato

Temperature

The producer gives 15 to 25 degrees as the effective range. Above 30 it becomes inactive.

Relative humidity

It requires relative humidity above 70 percent.

Release rate

From 50 to 100 individuals per square metre, rising to 350 at peak pressure. Whatever the number, at least 4,000 introduction points per hectare are needed, because the mite disperses slowly and coverage depends on the density of the points and not on the number of individuals alone.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt takes only young thrips larvae, never adults. It cannot be combined with any other generalist predatory mite.

Sources: 13 14 73

Amblyseius swirskii

Phytoseiidae. Predatory mite, generalist

Thrips Whiteflies Eriophyid and tarsonemid mites Spider mites, secondary not on tomato not on cucumber and cucurbits

Temperature

The lower developmental threshold is 11.3 degrees, but the population does not grow below 15.5. The distance between the two figures means the mite can complete its cycle without multiplying. Development is fastest at 30.1 and the upper threshold is 37.4.

Relative humidity

The optimum band runs from 55 to 85 percent. Below 40 percent the eggs desiccate and are lost before hatching.

Release rate

From 25 to 300 individuals per square metre.

Availability and legal status

Koppert, Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteThe gap between the developmental threshold and the population growth threshold explains why it fails in a cool spring greenhouse. It is native to the eastern Mediterranean, Greece included.

Sources: 2 4 73

Sources: 1 2 3 4 5 6 7 8 13 14 15 16 73 90

5. Substrate predatory mites

Thrips spend two of their stages inside the growing medium, where no canopy predator and no foliar spray reaches them. Sciarid flies spend their whole larval life there. The two substrate mites in this section cover exactly that floor, and for that reason they do not compete with the phytoseiids above but complement them.

Sources: 9 10 11 12 73 90

6. Predatory insects

Fifteen species from seven families, with three differences that govern their use. The first is where they lay. Anthocorids and mirids insert their eggs into plant tissue, so they cannot be counted, cannot be washed off, and establishment cannot be verified by counting eggs. In Anthocoris nemoralis eggs deposited outside plant tissue simply failed to hatch [21]. Ladybirds by contrast lay in clusters on the leaf, so the eggs can be counted but can also be sprayed.

The second is which stage feeds. In ten of the fifteen species both immatures and adults are predatory. In the green lacewing and both gall midges only the larva is predatory, and the adult feeds exclusively on pollen, nectar and honeydew [85]. That changes two things in practice: a pollen source in or beside the crop is needed to retain the adults, and most lacewing adults leave the greenhouse in any case [90].

The third is photoperiod, and this is where Greek conditions differ materially from northern European ones. Section 13 covers it.

Anthocorids

Orius laevigatus

Anthocoridae. Predatory bug

Thrips Whiteflies, secondary Spider mites, secondary

Temperature

It performs best above 20 degrees and performance declines above 30. The cycle from egg to adult closes in 9.6 days at 26.

Release rate

In greenhouse sweet pepper, 2 individuals per square metre gave the same thrips control as 6. The producer gives a range of 0.5 to 10, in groups of at least 50 individuals, so that a local density sufficient for mating is formed.

Availability and legal status

Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt inserts its eggs INTO plant tissue, so they cannot be counted and cannot be washed off. A nymph eats about 54 thrips larvae over its development, an adult up to 20 a day.

Sources: 17 18

Orius majusculus

Anthocoridae. Predatory bug

Thrips Whiteflies, secondary

Temperature

No published temperature thresholds were found for the species.

Release rate

No published release rate was found for the species.

Availability and legal status

Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteThe southern strain from Antalya, at the same latitude as the Peloponnese, enters reproductive diapause at 11.5 hours of light in 100 percent of females and at 12 hours in 25 percent. The northern strain needs 14 to 16 hours. An autumn release of a northern strain in Greece simply stops reproducing.

Sources: 19 20

Anthocoris nemoralis

Anthocoridae. Predatory bug

Pear and olive psyllids Thrips, secondary Aphids, secondary Spider mites, secondary Lepidopteran eggs (codling moth and others), secondary

Temperature

No published temperature threshold was found for the species.

Release rate

From 1,500 to 2,000 individuals per hectare, spread over two to four releases in consecutive weeks.

Availability and legal status

Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteOn natural psyllid prey it starts laying after 7.1 days. On a laboratory diet of Ephestia eggs the same period becomes 83.7 days, twelve times longer. A mass-reared population carries that delay into the orchard.

Sources: 21

Miridae

Of all the agents in this list the two mirids are at once the most effective and the most hazardous. They are zoophytophagous, feeding on both insects and plant. The nymph of Macrolophus pygmaeus completes development with no prey at all, needing roughly twenty percent more degree-days, 306 to 361 instead of 253 to 280 [22]. That very capacity keeps it in the crop when no pest is present, and that very capacity lets it feed on the plant once the pest is gone.

The consequence for the rate is that it is set by the damage, not by the efficacy. In pre-plant release trials at 0, 0.5, 1 and 2 individuals per plant, every rate significantly reduced whitefly and gave adequate control. Only 0.5 per plant did not increase crop damage [26]. Two independent papers therefore converge on the same protocol: one individual per two plants, in the transplant trays, five days before planting out [27].

Macrolophus has the reputation of being the safer of the two, and broadly it is, but the difference is not the one usually assumed. At high density, around 23.8 individuals per plant, flower abortion reached 12.2 percent and mean fruit weight also fell, whereas with Nesidiocoris the plant compensates for flower abortion by increasing the weight of the fruits that remain [24]. That is, Macrolophus does less damage, but without compensation.

Macrolophus pygmaeus

Miridae. Zoophytophagous predatory bug

Whiteflies Tuta absoluta Spider mites, secondary Aphids, secondary

Temperature

The developmental threshold, measured from egg to egg and therefore for the whole generation, is 8.5 degrees. Above it the generation requires 533 to 541 degree-days to close.

Release rate

The published strategy is 20 adults per plant with supplementary food for six to eight weeks. The figure describes a concentrated release on a limited part of the crop and is not a rate for the whole greenhouse.

Availability and legal status

Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteThe nymph completes development with NO prey at all, needing roughly 20 percent more degree-days. That is what keeps it in the crop through prey-free periods, and that is exactly what allows it to feed on the plant.

Sources: 22 23 24 91 92

Nesidiocoris tenuis

Miridae. Zoophytophagous predatory bug

Tuta absoluta Whiteflies Spider mites, secondary Aphids, secondary

Temperature

Generation time shows how strongly it depends on temperature: 14.9 days at 35 degrees, 21.8 at 25 and 86.7 at 15. At the low end the generation effectively does not close within the growing season.

Release rate

0.5 individuals per plant, that is one individual per two plants, introduced pre-plant inside the transplant trays, five days before planting out.

Availability and legal status

Koppert, Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteThe rate is set by the damage, not by the efficacy. Every rate tested controlled the whitefly, but only 0.5 per plant did not increase crop damage.

Sources: 25 26 27

Ladybirds

Five species with very different thermal profiles, and the difference is decisive for Greece. Adalia bipunctata does not develop at all at 35 degrees [28], while Propylea quatuordecimpunctata has an upper threshold of 36.0 degrees and the lowest thermal constant of the group at 218 degree-days [30]. In a Greek July greenhouse that difference is the difference between a population and nothing.

Adalia bipunctata

Coccinellidae. Predatory beetle, ladybird

Aphids

Temperature

On an aphid diet development stops below 10.06 degrees, and above that threshold the cycle requires 267.9 degree-days. Development is fastest from 23 to 27. At 35 there is no development at all, not merely a slowdown.

Release rate

On trees, one bag per 25 centimetres of stem diameter and up to three bags per tree. The rate scales with tree size and not with orchard area.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt lays eggs in clusters on the leaf underside, so they can be counted but also sprayed. It does not develop at all at 35 degrees, which in a Greek July greenhouse is a daily value.

Sources: 28 29

Propylea quatuordecimpunctata

Coccinellidae. Predatory beetle, ladybird

Aphids

Temperature

Development stops below 10.2 degrees and requires 218.0 degree-days above that threshold to complete the cycle. Development is fastest at 30.3 and the upper threshold is 36.0.

Release rate

No rate was found. The species is not widely available as a commercial product.

Availability and legal status

Andermatt. Not on the Greek National Catalogue of Macro-organisms; import proceeds through the EPPO PM 6/3 list.

NoteIts thermal constant is the lowest and its upper threshold the highest of the three aphidophagous ladybirds, which makes it the heat-tolerant species. In Greece its role is mainly the conservation of native populations.

Sources: 30

Cryptolaemus montrouzieri

Coccinellidae. Predatory beetle

Mealybugs Armoured scales, secondary

Temperature

Activity begins at 16 degrees and is optimal from 22 to 28. Above 33 prey searching ceases, and below 9 all activity ceases.

Relative humidity

The optimum band runs from 70 to 80 percent.

Release rate

Adults from 2 to 10 per square metre, or larvae from 5 to 40, repeated every one to two weeks.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteThe larva mimics a mealybug. Four characters separate them: waxy filaments on the BACK as well as the sides, twice the size of an adult mealybug, faster movement, and visible legs and mouthparts once the wax is brushed aside. A grower who cannot tell them apart sprays his own success.

Sources: 34 35

Rodolia cardinalis

Coccinellidae. Predatory beetle

Icerya purchasi (cottony cushion scale)

Temperature

Development stops below 10.8 degrees and requires 279 degree-days above that threshold. At 34 eggs per female fall to 9.3, and at 37 none hatch.

Release rate

It is not sold by the unit. It is already established throughout the Mediterranean, so what is at stake is the conservation of the existing population rather than the introduction of a new one.

Availability and legal status

Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt completes 8 to 12 generations a year while Icerya completes only 3 to 4. That asymmetry, not any particular voracity, explains its historical success. The only decision that matters is not to spray it out.

Sources: 33

Other predatory insects

Atheta coriaria (Dalotia coriaria)

Staphylinidae. Soil-dwelling predatory beetle

Sciarid flies and thrips pupae in the substrate Thrips

Temperature

The cycle from egg to adult takes 17.0 days at 26 degrees and 21 days at 21.

Relative humidity

It tolerates a wide band, from 40 to 99 percent, and is the least demanding species in this list as regards humidity.

Release rate

From 1 to 5 individuals per 0.93 square metres, or 100 to 1,000 individuals per greenhouse, repeated weekly to fortnightly. The 0.93 square metre unit comes from the square foot of the American source and is kept so that the figure remains verifiable.

Availability and legal status

Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt eats the thrips pupae in the substrate, where no canopy predator reaches. It is not combined with Stratiolaelaps, because it eats it.

Sources: 12 36

Chrysoperla carnea

Chrysopidae. Green lacewing, predatory neuropteran

Aphids Whiteflies, secondary Spider mites, secondary Thrips, secondary Mealybugs, secondary

Temperature

It needs an average of at least 12 degrees and performs best from 20 to 28. For the related Chrysoperla agilis the developmental threshold lies between 11.4 and 11.8 degrees, a value given for comparison that does not apply to carnea itself.

Release rate

No single rate per square metre was given. The producer adjusts the number by crop.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteONLY the larva is predatory. The adult feeds exclusively on pollen, nectar and honeydew, and most adults leave the greenhouse. One larva eats 300 to 400 aphids. On hairy leaves performance drops markedly.

Sources: 85 86 87 88 89

Aphidoletes aphidimyza

Cecidomyiidae. Predatory gall midge

Aphids

Temperature

It performs best from 20 to 30 degrees. For oviposition it needs a night temperature of at least 12 degrees, because egg laying takes place at night.

Relative humidity

It requires relative humidity above 70 percent.

Release rate

From 1 to 10 individuals per square metre at each release, repeated weekly.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteTwo independent reasons for failure. First, the larva drops to the ground to pupate and without one or two centimetres of moist medium the generation does not close. Second, at 9 hours of light 100 percent of larvae enter diapause, and in Greece the day falls below 15.5 hours from early August.

Sources: 83

Feltiella acarisuga

Cecidomyiidae. Predatory gall midge, spider mite specialist

Spider mites

Temperature

It performs best from 20 to 27 degrees.

Relative humidity

It requires relative humidity above 80 percent and is the most demanding species in this entire list in that respect. In a heavily ventilated greenhouse that level is hard to maintain.

Release rate

From 0.25 to 25 individuals per square metre, in at least three consecutive weekly releases.

Availability and legal status

Koppert. Listed on the Greek National Catalogue of Macro-organisms.

NotePhotoperiod on its own does NOT induce diapause, from 16 down to 8 hours, so unlike Aphidoletes it works through almost the whole growing season. The limiting factor is humidity. It also eats diapausing spider mites.

Sources: 84

Franklinothrips vespiformis

Aeolothripidae. Predatory thrips

Thrips Leafminers (Liriomyza), secondary Whiteflies, secondary Spider mites, secondary

Temperature

No published biology was located for the species, so there are no temperature thresholds to give.

Release rate

No published release rate was found for the species.

Availability and legal status

Andermatt. Not on the Greek National Catalogue of Macro-organisms; import proceeds through the EPPO PM 6/3 list.

NoteIt is NOT on the Greek National Catalogue of Macro-organisms, but it is in Appendix 1 of EPPO PM 6/3. It can therefore be imported into Greece lawfully through the EPPO route, using Template 1 of the ministerial decision.

Sources: 73 74

Sources: 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 82 83 84 85 86 87 88 89 90 91 92 94

7. Parasitoid wasps

Ten species, and three concepts a grower needs in order to use them correctly.

Aphid parasitoids

The three Aphidius species divide the work by two criteria, aphid size and temperature. colemani is for small aphids and warm periods, ervi for large ones, and matricariae for early spring and the unheated greenhouse. Under identical conditions matricariae is consistently about two days slower than colemani, but with a cooler optimum [37]. Aphelinus abdominalis covers the upper end, performing better than the Aphidius species above 28 degrees [90].

Aphidius colemani

Braconidae. Endoparasitoid wasp, koinobiont

Aphids not on tomato

Temperature

The cycle from egg to adult closes in 10.0 days at 25 degrees, and development stops below 2.97. It performs best from 20 to 25 and performance declines above 30.

Release rate

From 0.25 to 4 individuals per square metre, in at least three consecutive releases.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteThe aphid does not die at once. It keeps feeding, and if it is fourth instar or adult it keeps reproducing for two more days. The mummy appears 7 to 12 days later, so an assessment made earlier shows a failure that is not real. On tomato the glandular trichomes cut parasitism roughly tenfold.

Sources: 37 40 41 42

Aphidius ervi

Braconidae. Endoparasitoid wasp, koinobiont

Aphids not on tomato

Temperature

From oviposition to adult there are 12.1 days at 25 degrees and 25.0 days at 15. Development stops below 5.98, and above that threshold the cycle requires 229.73 degree-days to close.

Release rate

From 0.25 to 2 individuals per square metre, repeated weekly and begun preventively from planting.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteThis is the species for the LARGE aphids. Females fed sugar live eight times longer than those given only water, and they need at least two feeds a day. A sugar source inside the crop is not decoration.

Sources: 38 39

Whitefly parasitoids

The choice between the two is purely thermal and there is a number for it. The developmental threshold of Eretmocerus eremicus is 13.0 degrees, the highest of the aphelinids, while that of Encarsia formosa is 8.1 to 11.5 depending on strain. At 15 degrees Eretmocerus needs 79.3 days and Encarsia 48. At 32 degrees both converge on 14 days [46]. Encarsia is therefore the cool choice and Eretmocerus the warm one, and that is a measured quantity rather than commercial positioning.

Encarsia formosa

Aphelinidae. Endoparasitoid wasp, thelytokous

Whiteflies

Temperature

It performs best from 20 to 25 degrees and becomes insufficient once the 24-hour average falls below 17. It additionally needs a photoperiod of at least 12 hours, so temperature on its own is not a sufficient criterion.

Relative humidity

It operates from 50 to 80 percent relative humidity.

Release rate

From 1 to 10 individuals per square metre, preventively and repeated until control is achieved.

Availability and legal status

Koppert. Listed on the Greek National Catalogue of Macro-organisms.

NoteBeyond the roughly 5 whiteflies parasitised per day it eats another 3, which die without ever becoming mummies. Mummy counts therefore understate the real control by about a third. A black pupa with a ROUND exit hole is a success, a transparent one with a T-shaped slit is a whitefly that emerged normally.

Sources: 44 45

Scale and mealybug parasitoids

Leafminer and egg parasitoids

Trichogramma achaeae is the only agent in this whole list that kills the pest before any damage occurs, because it attacks the egg. That carries a cost: the release must be synchronised with moth oviposition rather than with the calendar, because as the host egg ages the chorion hardens and parasitism falls clearly [55]. Standard practice in trials is eggs younger than twenty-four hours, which is why the published protocol is two releases a week and not one [53].

Diglyphus isaea

Eulophidae. Ectoparasitoid wasp, idiobiont

Leafminers (Liriomyza)

Temperature

The cycle from egg to adult takes about 10 days at 25 degrees and 27 days at 15. Development stops below 9.2 and above that threshold it requires 161.8 degree-days.

Release rate

From 0.25 to 3 individuals per square metre, in at least three consecutive weekly releases.

Availability and legal status

Koppert. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt permanently paralyses the larva inside the mine and lays BESIDE it, not inside it. The mine stops growing at that moment. It leaves no mummy, but the mature larva leaves six black pellets that hold the leaf surfaces apart, and those are what the grower counts.

Sources: 50 51

Sources: 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 75 90 93

8. Entomopathogenic nematodes

Three species, and the choice between them is governed not by the pest but by two other things: soil temperature and foraging strategy.

Steinernema feltiae

Steinernematidae. Entomopathogenic nematode, symbiont Xenorhabdus bovienii

Sciarid flies and thrips pupae in the substrate Overwintering codling moth larvae in the soil Thrips Leafminers (Liriomyza) Capnodis (stone fruit flatheaded borer) Tuta absoluta, secondary

Temperature

It infects and establishes from 8 to 30 degrees, but reproduces only from 10 to 25. At 30 infectivity is lost and at 28 no progeny are produced. The host dies in 12 days at 8 degrees and in 2 days at 25.

Relative humidity

It needs a moist but not saturated substrate, because the nematode moves in the water film around the particles and under saturation oxygen is lacking.

Release rate

From 250,000 to 500,000 infective juveniles per square metre for soil application, and from 1 to 3 million per litre of spray for foliar application.

Availability and legal status

Koppert, Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt is the COLD species, the only one of the three that infects reliably below 12 degrees. In an autumn application against overwintering codling moth larvae it gave 90 percent in October while carpocapsae gave only 58.

Sources: 56 57 58 64 65

Steinernema carpocapsae

Steinernematidae. Entomopathogenic nematode, symbiont Xenorhabdus nematophila

Red palm weevil Capnodis (stone fruit flatheaded borer) Overwintering codling moth larvae in the soil Lepidopteran eggs (codling moth and others) Tuta absoluta

Temperature

It reproduces from 20 to 30 degrees and is most effective from 22 to 28. At 10 degrees it causes no codling moth mortality at all.

Relative humidity

It needs wetting in order to move, yet it is the most desiccation-tolerant of the three species in this list.

Release rate

In soil it is applied at the same orders of magnitude as Steinernema feltiae. For palms the figures are 5 to 20 litres per palm, or 1 million juveniles per litre of spray.

Availability and legal status

Koppert, Bio-Insecta, Andermatt. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt is the AMBUSHER. It stands on its tail near the surface and attaches to passing hosts, so it reaches mobile surface-active insects and not the sedentary larvae of the deeper soil. At 85 percent relative humidity more than 80 percent survive two hours, while the other two species die completely.

Sources: 56 59 60 61 66

Heterorhabditis bacteriophora

Heterorhabditidae. Entomopathogenic nematode, symbiont Photorhabdus

Vine weevils and root-feeding chafer grubs Capnodis (stone fruit flatheaded borer) Sciarid flies and thrips pupae in the substrate, secondary Tuta absoluta, secondary

Temperature

The producer gives it as active from 16 to 35 degrees, with an optimum from 19 to 33. Performance falls below 20, which makes it the warm-adapted species of the three.

Relative humidity

It is strictly a soil species and does not tolerate desiccation.

Release rate

From 250,000 to 500,000 infective juveniles per square metre.

Availability and legal status

Koppert, Bio-Insecta. Listed on the Greek National Catalogue of Macro-organisms.

NoteIt is the CRUISER and the only one of the three that bores directly through the host cuticle with a dorsal tooth. It moves actively through the medium and reaches the sedentary root-feeding larvae the ambusher never encounters. At 85 percent humidity it dies completely within two hours, so never foliar.

Sources: 56 60 62 63

The growing medium matters more than is usually suspected. Across seven soils, infectivity of H. bacteriophora was highest in potting medium and lowest in acidic sand, while its persistence was shortest precisely where infectivity was greatest. The authors warn explicitly against generalising soil effects from one species to another [62].

Sources: 56 57 58 59 60 61 62 63 64 65 66 72 90

9. Full table of species, products and suppliers

The table brings together all thirty-seven species. Suppliers are taken from the catalogues of Koppert Greece, Bio-Insecta and Andermatt Hellas as they stood in September 2026. The catalogue column shows whether the species appears on the Greek National Catalogue of Macro-organisms [75]. The search filters scientific name, family, target and supplier at the same time.

Sources: 73 75 90

10. Release rates and timing

Most circulating rates come from producer technical sheets. There are however six cases where the rate has been measured in peer-reviewed work, and those deserve separate treatment because in two of them the result was the opposite of the commercial advice.

Sources: 1 18 26 27 47 50 53 55 65 66 90 91 92

11. Compatibility with plant protection products

A single spray can cancel an entire release programme, and what matters is not only whether it kills but for how long it stays dangerous. The international rating system is that of the IOBC, which places each product in one of four classes [68]. There is a trap here that appears often in the literature: the class boundaries differ between laboratory and field, and they are not interchangeable.

The reason for the difference is that the laboratory test uses a fresh dry residue on glass, that is the worst possible exposure, so a product must be nearly inert to be rated harmless. In the field exposure is realistic and the threshold tightens.

Persistence, which often matters more than the class

In trials on Aphytis melinus in citrus, most of the harmful products lost their negative effect somewhere between one and six weeks. Lambda-cyhalothrin remained harmful eleven weeks after application [71]. A single pyrethroid application is therefore enough to cancel a whole season of releases, however well everything else was done.

Which products are dangerous and which are not

In laboratory IOBC assessment on adult Amblyseius swirskii, sulfoxaflor, flonicamid, flubendiamide, metaflumizone, methoxyfenozide, spiromesifen and spirotetramat were rated harmless, while abamectin, deltamethrin and spinosad were rated harmful [69]. In corresponding work on three other beneficials, pyridaben, acetamiprid, spinosad and propargite were harmful to Aphidius colemani and Aphidoletes aphidimyza, while Neoseiulus cucumeris was clearly the least sensitive of the three [70].

Sources: 67 68 69 70 71 72 90

12. Eight documented ways a release fails

Each of the following has been measured and published. None is speculation.

Sources: 2 3 12 19 20 25 34 40 41 42 82 83 90

13. What changes under Greek conditions

Nearly all technical sheets and a large part of the trial work come from the Netherlands, Belgium and Britain. Four parameters do not transfer unchanged.

Photoperiod, which is the most serious

The critical photoperiod depends on the latitude the strain came from, and the difference is very large. The southern strain of Orius majusculus from Antalya, at 37.0 degrees north and therefore at the same latitude as the Peloponnese and Crete, stays reproductively active on just 12 hours of light, while the northern strain needs 14 to 16 [19]. A northern strain released into a Greek autumn greenhouse meets days well below its own threshold and stops laying. The same applies to Aphidoletes aphidimyza, which enters diapause below fifteen and a half hours, a threshold crossed in Greece from early August [83].

There is a remedy and it is cheap: low-intensity night lighting. For Orius majusculus 10 lux suffices [19], while for Aphidoletes radiation below 5.5 lux does not [83]. It must however be preventive, because once diapause is established it does not break easily [20].

Two species do not have this problem and deserve preference in autumn plantings. Macrolophus pygmaeus at ten hours of light merely slows by one or two days, with no reproductive diapause, and the Rome strain matures faster than the Sochi one [23]. Feltiella acarisuga does not enter photoperiodic diapause at all [84].

Summer temperature

Values that are extreme in northern Europe are simply July in Greece. Adalia bipunctata does not develop at all at 35 degrees [28]. In Rodolia cardinalis eggs per female fall to 9.3 at 34 degrees and hatch fails completely at 37 [33], while the adults survive, so a midsummer reproductive pause is to be expected in Greek citrus in July and August. In Neoseiulus californicus females still oviposit at 37.5 degrees but no eggs hatch [5]. By contrast Propylea quatuordecimpunctata with an upper threshold of 36.0 degrees [30] and Amblyseius swirskii with a population growth optimum of 30.1 [4] are built for these conditions.

Humidity

This is the most underestimated constraint in Greece, and the only species with a genuine dose response curve is Phytoseiulus persimilis [3]. For the rest there are only qualitative producer statements: above 70 percent for cucumeris, above 65 for andersoni, above 60 for montdorensis, and above 80 for Feltiella [90]. In a Greek summer greenhouse and outdoors, those thresholds are not a given.

What is already here

Two observations that change the economics. Amblyseius swirskii is native to the eastern Mediterranean, with Greece among its countries of origin [73], so releasing it is not the introduction of a foreign organism. Rodolia cardinalis is already established throughout the Mediterranean and is not sold by the unit, so the only decision that matters for it is not to spray it out [33]. And Amblyseius andersoni overwinters in the leaf litter and climbs into the canopy on its own, so in olive, grapevine and top fruit it can be conserved rather than bought each year [16].

Sources: 3 4 5 7 16 19 20 22 23 28 30 31 32 33 73 83 84 85 86 88 90

14. Sources

Numbers in the text refer to the list below. Where a value comes from a producer technical sheet rather than from peer-reviewed work, this is stated explicitly in the text.

• [1] McMurtry, J. and Croft, B. (1997). Life-styles of phytoseiid mites and their roles in biological control. Annual Review of Entomology 42:291-321. Source for the four lifestyle types of phytoseiid mites and what each type means in practice.
• [2] Lopez, L. and Liburd, O. (2023). Meet Amblyseius swirskii, a commonly used predatory mite in vegetable crops. Journal of Integrated Pest Management 14(1):20. Source for subtype III-b, for the 40 percent humidity limit on egg survival, for the list of suitable and unsuitable pollens, and for why the species fails on tomato and cucurbits.
• [3] Le Hesran, S. et al. (2019). Phenotypic variation in egg survival in the predatory mite Phytoseiulus persimilis under dry conditions. Biological Control 130:88-94. Source for the egg hatch curve against relative humidity, for the RH50 of 66.8 percent, and for the finding that five commercial strains do not differ genetically in dry-condition egg survival.
• [4] Lee, H. and Gillespie, D. (2011). Life tables and development of Amblyseius swirskii at different temperatures. Experimental and Applied Acarology 53(1):17-27. Source for the developmental threshold of 11.3 degrees and, separately, for the population growth threshold of 15.49 degrees.
• [5] Gotoh, T., Yamaguchi, K. and Mori, K. (2004). Effect of temperature on life history of the predatory mite Neoseiulus californicus. Experimental and Applied Acarology 32:15-30. Source for the developmental threshold of 10.3 degrees, the thermal constant of 86.2 degree-days, and the failure of eggs to hatch at 37.5 degrees.
• [6] Li, Y. et al. (2019). Effects of temperature on a Chinese population of Amblyseius andersoni fed with Tetranychus urticae. Acarologia 59(4):475-483. Source for the failure of eggs to hatch at 16 degrees, for fecundity of 45.68 eggs at 25 and 9.13 at 17, and for the sex ratio.
• [7] Samaras, K., Pappas, M., Fytas, E. and Broufas, G. (2019). Pollen provisioning enhances the performance of Amblydromalus limonicus on an unsuitable prey. Frontiers in Ecology and Evolution 7:122. Source for 0.009 eggs per female per day on spider mite prey against 1.6 on cattail pollen. Greek work, Democritus University of Thrace.
• [8] Knapp, M., van Houten, Y., Hoogerbrugge, H. and Bolckmans, K. (2013). Amblydromalus limonicus as a biocontrol agent: literature review and new findings. Acarologia 53(2):191-202. Source for the finding that the species has a lower thermal optimum than the subtropical swirskii and montdorensis.
• [9] Wright, E. and Chambers, R. (1994). The biology of the predatory mite Hypoaspis miles, a potential biological control agent of Bradysia paupera. Entomophaga 39(2):225-235. Source for the developmental threshold of 10 to 12 degrees and, critically, for the finding that predation on sciarid eggs is negligible and pupae are not attacked at all.
• [10] Yao et al. (2021). Comparing the life table and population projection of Gaeolaelaps aculeifer and Stratiolaelaps scimitus. Agronomy 11(6):1062. Source for fecundity of 28.46 eggs per female and for adult longevity at 25 degrees.
• [11] Beretta, G. et al. (2022). Review: predatory soil mites as biocontrol agents of above and below ground plant pests. Experimental and Applied Acarology 87:143-162. Source for the comparison of Macrocheles and Gaeolaelaps and for the explicit statement that applied studies on Macrocheles robustulus are lacking.
• [12] Cloyd, R. (2023). Stratiolaelaps scimitus: biological control agent of fungus gnats and the western flower thrips. MF3632, Kansas State University Extension. Source for development time by temperature, for the restriction to the top 2.5 centimetres of the medium, and for the explicit finding that the species alone does not suffice. Also for the antagonism with Dalotia coriaria.
• [13] Cornell University IPM Program. Neoseiulus cucumeris, predatory mite. Biocontrol Fact Sheet. Source for development in 7 to 11 days, adult longevity of 28 to 35 days, and ineffectiveness on tomato because of glandular trichomes.
• [14] Yazdanpanah, S. and Fathipour, Y. (2024). The impact of different photoperiod regimes on vital life traits of Amblyseius swirskii and Neoseiulus cucumeris. Experimental and Applied Acarology 93(3):597-608. Source for the absence of any photoperiod effect on swirskii across five regimes, which is the cleanest evidence that it has no photoperiodic diapause.
• [15] Veerman, A. (1992). Diapause in phytoseiid mites: a review. Experimental and Applied Acarology 14:1-60. Source for the principle that non-diapausing strains are artificially selected and trade winter survival for continuous reproduction. Used for the principle only, not for species-specific figures.
• [16] Szabo, A. and Penzes, B. (2013). A new method for the release of Amblyseius andersoni in young apple orchards. European Journal of Entomology 110(3):477-482. Source for overwintering in the leaf litter, the spring migration into the canopy, and the litter-bag establishment method.
• [17] Gallego, F. et al. (2022). Effect of the amount of Ephestia kuehniella eggs for rearing on development, survival and reproduction of Orius laevigatus. Insects 13(3):250. Source for development in 9.6 days at 26 degrees and for fecundity of 46.8 to 49.0 eggs per female.
• [18] Weintraub, P., Pivonia, S. and Steinberg, S. (2011). How many Orius laevigatus are needed for effective western flower thrips management in sweet pepper?. Crop Protection 30(11):1443-1448. Source for the finding that 2 individuals per square metre gave statistically the same control as 6, with no difference in yield quantity or quality.
• [19] Unal Bahsi, S. and Tunc, I. (2012). The response of a southern strain of Orius majusculus to photoperiod and light intensity: biological effects and diapause induction. Biological Control 63(2):157-163. Source for the critical photoperiod of 11.5 to 12 hours in the southern strain, for 100 percent diapause at 11.5 hours, and for the prevention of diapause by light of 10 lux and above.
• [20] van den Meiracker, R. (1994). Induction and termination of diapause in Orius predatory bugs. Entomologia Experimentalis et Applicata 73:127-137. Source for the critical photoperiod of 14 to 16 hours in the northern strain and for the finding that diapause is not terminated within 14 days even when temperature and daylength are raised.
• [21] Yanik, E. and Ugur, A. (2005). Investigations on the fecundity of predator Anthocoris nemoralis under laboratory and natural conditions. Turkish Journal of Entomology 29(2):111-124. Source for a pre-oviposition period of 7.1 days on natural prey against 83.7 days on Ephestia eggs, for fecundity, and for the finding that eggs laid outside plant tissue do not hatch.
• [22] Perdikis, D. and Lykouressis, D. (2002). Thermal requirements for development of the polyphagous predator Macrolophus pygmaeus. Environmental Entomology 31(4):661-667. Source for the egg-to-egg threshold of 8.5 degrees, for 533 to 541 degree-days, and for the finding that the nymph completes development without prey on 306 to 361 degree-days. Greek work, Agricultural University of Athens.
• [23] Pazyuk, I. and Reznik, S. (2016). Influence of photoperiod on development and maturation of Macrolophus pygmaeus. Entomological Review 96(3):274-279. Source for the absence of reproductive diapause at 10 hours of light and for the difference between the Rome and Sochi strains.
• [24] Ramirez-Soria, M. et al. (2018). How safe is it to rely on Macrolophus pygmaeus as a biocontrol agent in tomato crops?. Frontiers in Ecology and Evolution 6:132. Source for 12.2 percent flower abortion at high predator density, for the reduction in mean fruit weight, and for the contrast with Nesidiocoris, where the plant compensates.
• [25] Sanchez, J. (2009). Density thresholds for Nesidiocoris tenuis in tomato crops. Biological Control 51(3):493-498. Source for the absolute safe density of 0.65 individuals per leaf, for the 5 per leaf permitted when more than 26 whitefly immatures are present, and for the critical predator to prey ratio of 0.168.
• [26] Calvo, F., Bolckmans, K. and Belda, J. (2012). Release rate for a pre-plant application of Nesidiocoris tenuis for Bemisia tabaci control in tomato. BioControl. Source for the finding that all rates controlled the whitefly but only 0.5 per plant did not increase crop damage.
• [27] Calvo, F., Lorente, M., Stansly, P. and Belda, J. (2012). Preplant release of Nesidiocoris tenuis and supplementary tactics for control of Tuta absoluta and Bemisia tabaci in greenhouse tomato. Entomologia Experimentalis et Applicata 143:111-119. Source for the establishment trajectory: a decline in weeks 1 to 3 and stabilisation above 2 individuals per leaf from week five.
• [28] Jalali, M., Tirry, L., Arbab, A. and De Clercq, P. (2010). Temperature dependent development of the two spotted ladybeetle Adalia bipunctata. Journal of Insect Science 10:124. Source for the threshold of 10.06 degrees, the 267.9 degree-days, and the complete absence of development at 35 degrees.
• [29] Bonte, M., Samih, M. and De Clercq, P. (2010). Development and reproduction of Adalia bipunctata on factitious and artificial foods. BioControl 55:485-491. Source for the fecundity range of 264 to 1,864 eggs depending on rearing diet and for the fall in survival to 40 to 55 percent on poor diets.
• [30] Papanikolaou, N., Milonas, P., Kontodimas, D., Demiris, N. and Matsinos, Y. (2013). Temperature dependent development, survival, longevity and fecundity of Propylea quatuordecimpunctata. Annals of the Entomological Society of America 106(2):228-234. Source for the threshold of 10.2 degrees, the 218.0 degree-days, the upper threshold of 36.0 and the maximum fecundity of 724.6 eggs at 25 degrees. Greek work, Benaki Phytopathological Institute.
• [31] Kontodimas, D., Eliopoulos, P., Stathas, G. and Economou, L. (2004). Comparative temperature dependent development of Nephus includens and Nephus bisignatus preying on Planococcus citri. Environmental Entomology 33(1):1-11. Source for the threshold of 10.9 degrees, the thermal constant of 472.8 to 490.5 degree-days and the absence of development at 10 and at 37.5 degrees. Greek work.
• [32] Kontodimas, D. et al. (2007). Life table parameters of the pseudococcid predators Nephus includens and Nephus bisignatus. European Journal of Entomology 104(3):407-415. Source for maximum fecundity of 162.8 eggs at 25 degrees and for the maximum rate of population increase at 30. Greek work.
• [33] Grafton-Cardwell, E., Gu, P. and Montez, G. (2005). Effects of temperature on development of vedalia beetle, Rodolia cardinalis. Biological Control 32(3):473-478. Source for the threshold of 10.8 degrees, the 279 degree-days, the fall to 9.3 eggs per female at 34 and the complete failure of egg hatch at 37.
• [34] UC Statewide IPM Program. Mealybug destroyer, Cryptolaemus montrouzieri. Natural Enemies Gallery, University of California. Source for the four diagnostic characters that separate the larva from a mealybug, for the 200 to 400 eggs per female, and for the fact that it is a tropical species that does not overwinter.
• [35] Harbi, A., Abbes, K., Rahmouni, R. and Chermiti, B. (2024). Life table and population growth parameters of Cryptolaemus montrouzieri. Phytoparasitica. Source for fecundity of 37.41 to 60.1 eggs per female depending on the mealybug species, which diverges sharply from the 200 to 400 of the preceding source.
• [36] Kansas State University, R. Cloyd laboratory (2012). Life history characteristics of the rove beetle Dalotia coriaria. Journal of the Kansas Entomological Society 86(2). Source for development in 17.0 days at 26 degrees, fecundity of 90.2 eggs, and consumption of 3.9 to 15.3 sciarid larvae per 24 hours.
• [37] Zamani, A., Talebi, A., Fathipour, Y. and Baniameri, V. (2007). Effect of temperature on life history of Aphidius colemani and Aphidius matricariae. Environmental Entomology 36(2):263-271. Source for the comparison of the two species under identical conditions: 10.0 against 11.9 days at 25 degrees, and thresholds of 2.97 against 3.37.
• [38] Malina, R. and Praslicka, J. (2008). Effect of temperature on the developmental rate, longevity and parasitism of Aphidius ervi. Plant Protection Science 44(1):19-24. Source for development time by temperature, for the threshold of 5.98 degrees and for the 229.73 degree-days.
• [39] Azzouz, H., Giordanengo, P., Wackers, F. and Kaiser, L. (2004). Effects of feeding frequency and sugar concentration on behavior and longevity of the adult aphid parasitoid Aphidius ervi. Biological Control 31(3):445-452. Source for the eightfold increase in longevity with sugar and for the need of at least two feeds a day.
• [40] Frank, S., Prado, S. and Jandricic, S. (2015). Ecological interactions affecting the efficacy of Aphidius colemani in greenhouse crops. Insects 6(2):538-575. Source for the roughly tenfold fall in parasitism on plants with glandular trichomes and for the 5.6 percent of mortality attributable to parasitism there.
• [41] Nagasaka, K., Takahasi, N. and Okabayashi, T. (2010). Impact of secondary parasitism on Aphidius colemani in the banker plant system. Applied Entomology and Zoology 45(4):541-550. Source for the seasonal rise in hyperparasitism from below 35 percent in February to above 70 percent in May and June.
• [42] van Neerbos, F. et al. (2024). Seasonal changes in aphid hyperparasitoid occurrence in sweet pepper and raspberry in Belgium. BioControl. Source for 42 percent hyperparasitism in greenhouse sweet pepper.
• [43] Bugti, G. et al. (2017). Role of the aphid species and their feeding locations in parasitization behavior of Aphelinus abdominalis. PLOS ONE 12(9):e0184080. Source for the finding that under 6 percent of mortality is due to host feeding, which contradicts the commercial claim.
• [44] Hu, J., Gelman, D. and Blackburn, M. (2002). Growth and development of Encarsia formosa in the greenhouse whitefly: effect of host age. Archives of Insect Biochemistry and Physiology 49:125-136. Source for development time by host age, from 21.15 days in a first instar host to 14.21 in a third, at 26 degrees.
• [45] UC Statewide IPM Program. Whitefly Encarsia formosa parasitoid. Natural Enemies Gallery, University of California. Source for roughly 5 hosts parasitised and 3 consumed per day, and for the distinction between the round exit hole and the T-shaped slit.
• [46] Qiu, Y., van Lenteren, J., Drost, Y. and Posthuma-Doodeman, J. (2004). Life history parameters of Encarsia formosa, Eretmocerus eremicus and E. mundus. European Journal of Entomology 101(1):83-94. Source for the 13.0 degree threshold of Eretmocerus against 8.1 to 11.5 for Encarsia, and for 79.3 against 48 days at 15 degrees.
• [47] UC Statewide IPM Program. California red scale Aphytis parasitoid. Natural Enemies Gallery, and UC IPM Phenology Model Database. Source for the threshold of 9.7 degrees, the 226.5 degree-days, the preference for third-instar virgin female scales, and the finding that host feeding at times kills as many scales as parasitism.
• [48] Andreason, S., Triapitsyn, S. and Perring, T. (2019). Untangling the Anagyrus pseudococci species complex. Biological Control 129:65-82. Source for the finding that the material traded as Anagyrus pseudococci or Anagyrus sp. near pseudococci is in fact Anagyrus vladimiri.
• [49] Chormanski, T. and Cave, R. (2015, rev. 2018). Anagyrus pseudococci. UF/IFAS Extension EENY619. Source for the viable range of 14 to 34 degrees, for development in 79.3 days at 14 and 10.5 at 34, and for the finding that adult female mealybugs yield the most and the most female-biased offspring.
• [50] Bazzocchi, G., Lanzoni, A., Burgio, G. and Fiacconi, M. (2003). Effects of temperature and host on the pre imaginal development of the parasitoid Diglyphus isaea. Biological Control 26(1):74-82. Source for development time by temperature and for the 161.8 degree-days above 9.2 degrees.
• [51] Zhang, Y. et al. (2014). Comparing immature development and life history traits in two coexisting host feeding parasitoids, Diglyphus isaea and Neochrysocharis formosa. Journal of Integrative Agriculture 13(12):2690-2700. Source for 126.6 eggs per female and for the finding that each host-feeding event yields 2.7 extra eggs and 0.4 extra days of life.
• [52] del Pino, M., Gallego, J., Hernandez Suarez, E. and Cabello, T. (2020). Effect of temperature on life history and parasitization behavior of Trichogramma achaeae. Insects 11(8):482. Source for the threshold of 10.51 degrees, the 138.27 degree-days, the optimum at 20 degrees and the absence of viable progeny at 35.
• [53] Cabello, T. et al. (2012). Biological control strategies for the South American tomato moth in greenhouse tomatoes. Journal of Economic Entomology 105(6):2085-2096. Source for 85.63 percent parasitism with eight releases of 50 per square metre and for 91.03 percent with a single release of 100.
• [54] Chailleux, A., Biondi, A., Han, P., Tabone, E. and Desneux, N. (2013). Suitability of the pest plant system Tuta absoluta and tomato for Trichogramma parasitoids. Journal of Economic Entomology 106(6):2310-2321. Source for the finding that offspring developing on Tuta in tomato show lower parasitism, wing deformation and shorter life, and contribute little to control.
• [55] Jiang, Z. et al. (2025). Assessing parasitism and suitability of three Trichogramma parasitoids on Tuta absoluta based on parasitoid and host ages. Crop Protection 190:107099. Source for the decline in parasitism and adult emergence as the host egg ages from 12 to 96 hours. T. achaeae was not among the species tested.
• [56] Grewal, P., Selvan, S. and Gaugler, R. (1994). Thermal adaptation of entomopathogenic nematodes: niche breadth for infection, establishment and reproduction. Journal of Thermal Biology 19(4):245-253. Source for the separate temperature ranges of infection, establishment and reproduction in each nematode species.
• [57] Hazir, S., Stock, S., Kaya, H., Koppenhofer, A. and Keskin, N. (2001). Developmental temperature effects on five geographic isolates of Steinernema feltiae. Journal of Invertebrate Pathology 77:243-250. Source for the absence of progeny at 28 degrees and of infectivity at 30, and for host death time by temperature.
• [58] Lacey, L., Arthurs, S., Unruh, T., Headrick, H. and Fritts, R. (2006). Entomopathogenic nematodes for control of codling moth in apple and pear orchards. Biological Control 37(2):214-223. Source for the comparison of 90 percent with S. feltiae against 58 percent with S. carpocapsae in an October application, which is the argument for choosing the species by season.
• [59] Lacey, L. and Unruh, T. (1998). Entomopathogenic nematodes for control of codling moth: effect of nematode species, concentration, temperature and humidity. Biological Control 13(3):190-197. Source for zero mortality at 10 degrees and for the 83 percent reduction in adult emergence at 50 juveniles per square centimetre.
• [60] Ramakrishnan, J. et al. (2022). Survival and efficacy of entomopathogenic nematodes on exposed surfaces. Scientific Reports 12:4629. Source for the complete death of S. feltiae and H. bacteriophora within two hours at 85 percent humidity, against more than 80 percent survival in S. carpocapsae.
• [61] Gaugler, R. and Boush, G. (1978). Effects of ultraviolet radiation and sunlight on the entomogenous nematode Neoaplectana carpocapsae. Journal of Invertebrate Pathology 32(3):291-296. Source for the 6.9 percent loss of pathogenicity at thirty minutes and 94.9 percent at sixty minutes of direct sunlight.
• [62] Koppenhofer, A. and Fuzy, E. (2006). Effect of soil type on infectivity and persistence of entomopathogenic nematodes. Journal of Invertebrate Pathology 92(1):11-22. Source for the difference in infectivity by soil type and for the explicit warning not to generalise soil effects between species.
• [63] Batalla-Carrera, L., Morton, A. and Garcia-del-Pino, F. (2010). Efficacy of entomopathogenic nematodes against Tuta absoluta in laboratory and greenhouse conditions. BioControl 55:523-530. Source for larval mortality of 78.6 to 100 percent and for the 87 to 95 percent reduction of infestation in greenhouse trials.
• [64] Buitenhuis, R. and Shipp, J. (2005). Efficacy of Steinernema feltiae as influenced by Frankliniella occidentalis developmental stage and host plant stage. Journal of Economic Entomology 98(5):1480-1485. Source for the finding that only the soil-dwelling prepupal and pupal stages are susceptible, while foliar application gives no meaningful mortality.
• [65] Jagdale, G., Casey, M., Grewal, P. and Lindquist, R. (2004). Application rate and timing, potting medium and host plant effects on the efficacy of Steinernema feltiae against the fungus gnat. Biological Control 29(2):296-305. Source for the effective rates against sciarid flies and for the finding that the growing medium materially changes the outcome.
• [66] Nasouri, H. (2024). Capnodis tenebrionis, an important pest of stone fruits in the Mediterranean basin. Journal of Integrated Pest Management 15(1):20. Source for 59 to 100 percent mortality of neonate larvae and for 75 to 97 percent field control at 1 to 1.5 million juveniles per tree.
• [67] Desneux, N., Decourtye, A. and Delpuech, J. (2007). The sublethal effects of pesticides on beneficial arthropods. Annual Review of Entomology 52:81-106. Source for the distinction between acute toxicity and sublethal effects on fecundity, longevity and searching behaviour.
• [68] Sterk, G. et al. (1999). Results of the seventh joint pesticide testing programme carried out by the IOBC/WPRS working group. BioControl 44:99-117. Source for the IOBC four-class rating scheme and for the residue persistence classes.
• [69] Fernandez, M. et al. (2017). Compatibility of sulfoxaflor and other modern pesticides with adults of the predatory mite Amblyseius swirskii. BioControl 62(2):197-208. Source for the IOBC classification: flonicamid, spirotetramat and spiromesifen harmless, abamectin, deltamethrin and spinosad harmful.
• [70] Stara, J., Ourednickova, J. and Kocourek, F. (2011). Laboratory evaluation of the side effects of insecticides on Aphidius colemani, Aphidoletes aphidimyza and Neoseiulus cucumeris. Journal of Pest Science 84:25-31. Source for the finding that the same product is classified differently for different beneficials, and for the example of methoxyfenozide, slightly harmful to the mite but moderately harmful to the parasitoid on only 11.4 percent mortality.
• [71] Gonzalez-Zamora, J., Castillo, M. and Avilla, C. (2013). Side effects of different pesticides used in citrus on the adult stage of the parasitoid Aphytis melinus and its progeny. Spanish Journal of Agricultural Research 11(2):494-504. Source for the finding that lambda-cyhalothrin remained harmful eleven weeks after application, while most other harmful products lost their effect within one to six weeks.
• [72] Ozdemir, E., Inak, E., Evlice, E. and Laznik, Z. (2020). Compatibility of entomopathogenic nematodes with pesticides registered in vegetable crops under laboratory conditions. Journal of Plant Diseases and Protection 127(4):529-535. Source for the finding that spiromesifen and spinosad left survival of H. bacteriophora intact but significantly reduced its reproduction, a sublethal effect in nematodes as well.
• [73] EPPO (2021). PM 6/3 (5) Biological control agents safely used in the EPPO region. EPPO Bulletin 51:452-454, updated annually. Source for the positive list of biological control agents, for the years of first use and the countries of use, and for the restriction of N. californicus to non-diapausing strains.
• [74] Ministerial Decision 10522/117908 of 22 September 2014 (Government Gazette B 2622/2014), Greece. Establishment of a National Catalogue of Plant Protection Preparations containing Macro-organisms, and licensing of domestic production units. Greek title: «Κατάρτιση Εθνικού Καταλόγου των Σκευασμάτων Φυτοπροστασίας που περιέχουν Μακρο-οργανισμούς». Source for the Greek regime: compulsory registration in the national catalogue of preparations containing macro-organisms, prohibition on marketing an unregistered preparation, restriction of imports to organisms on the national or the EPPO list, and compulsory display of the registration number on the label.
• [75] Greek Ministry of Rural Development and Food, Directorate of Plant Produce Protection. National Catalogue of Macro-organisms. as amended by Ministerial Decisions 3791/52279 (Gazette B 1308/2018) and 10253/248479 (Gazette B 3810/2019). Source for the 53 species registered in Greece and for which of the species in this article are included or absent.
• [76] Regulation (EC) No 1107/2009 of the European Parliament and of the Council. concerning the placing of plant protection products on the market. Source for the definitions in Articles 2 and 3, which limit the scope to substances and micro-organisms and leave macro-organisms outside.
• [77] Regulation (EU) 2018/848 on organic production. Annex II, Part I, points 1.10.1 and 1.10.2. Source for the fact that protection by natural enemies is named first among the preventive measures and does not fall under the input authorisation regime of Article 24.
• [78] Bale, J. (2011). Harmonization of regulations for invertebrate biocontrol agents in Europe: progress, problems and solutions. Journal of Applied Entomology 135:503-513. Source for the finding that regulation of beneficial macro-organisms is left to member states and differs considerably between them, and that only for nematodes is information on the bacterial symbiont usually required.
• [79] van Lenteren, J. (2012). The state of commercial augmentative biological control: plenty of natural enemies, but a frustrating lack of uptake. BioControl 57(1):1-20. Source for the overall picture of commercial augmentative biological control and for the gap between the number of available species and actual uptake.
• [80] Heimpel, G. and Mills, N. (2017). Biological Control: Ecology and Applications. Cambridge University Press. Source for the distinction between conservation, classical and augmentative biological control, and for the theoretical framework of intraguild predation.
• [81] Riddick, E. (2022). Topical collection: natural enemies and biological control of plant pests. Insects 13:421. Source for the overall picture of recent research directions and for the identification of the individual studies used below.
• [82] Golsteyn, L. et al. (2021). Intraguild interactions between the mealybug predators Cryptolaemus montrouzieri and Chrysoperla carnea. Insects 12:655. Source for the finding that the two predators eat one another, usually in favour of the lacewing, and that abundant alternative prey significantly reduces encounters.
• [83] Gilkeson, L. and Hill, S. (1986). Diapause prevention in Aphidoletes aphidimyza by low intensity light. Environmental Entomology 15:1067-1069. Source for 100 percent diapause at 9 hours of light with a dark night and for the finding that radiation below 5.5 lux does not prevent it.
• [84] Gillespie, D. and Quiring, D. (2002). Diapause induction in Feltiella acarisuga. The Canadian Entomologist 134:69-75. Source for the finding that photoperiod alone, from 16 down to 8 hours, does NOT induce diapause, in contrast to Aphidoletes.
• [85] Pappas, M., Broufas, G. and Koveos, D. (2011). Chrysopid predators and their role in biological control. Journal of Entomology 8(3):301-326. Source for the fact that Chrysoperla adults are not predatory, for the three larval instars, for the stalked eggs and for the photoperiodic regulation of diapause. Greek work, Democritus University of Thrace.
• [86] Pappas, M. et al. (2013). Temperature dependent development of Chrysoperla agilis. Biological Control 64:291-298. Source for the developmental threshold of 11.4 to 11.8 degrees in a European cryptic species of the carnea group.
• [87] Henry, C., Brooks, S., Thierry, D., Duelli, P. and Johnson, J. (2001). The common green lacewing and the sibling species problem. In Lacewings in the Crop Environment, Cambridge University Press. Source for the finding that Chrysoperla carnea is not one species but a complex of cryptic species separated by courtship song rather than by morphology.
• [88] Athanasiadis, A., Pappas, M. and Broufas, G. (2021). Life history traits of Chrysoperla agilis. Insects 12:560. Source for fecundity of 421.1 eggs and development in 22.6 days at 25 degrees in a Mediterranean species of the group. Greek work.
• [89] Shakoor, A. et al. (2025). Life history of Chrysoperla carnea. Biology 14:10. Source for stage durations and for fecundity of 181.0 eggs per female at 25 degrees, which must be read together with the diet and the temperature.
• [90] Producer technical sheets: Koppert Greece, Bio-Insecta, Andermatt Hellas, Biobest, Bioline AgroSciences. accessed September 2026. Source for release rates, storage conditions, application instructions and the warnings against combining species. Every figure from these sources is explicitly flagged as producer information in the text.
• [91] Sanchez, J., Lopez-Gallego, E., Perez-Marcos, M. and Perera-Fernandez, L. (2020). The effect of banker plants and pre plant release on the establishment and pest control of Macrolophus pygmaeus in tomato greenhouses. Journal of Pest Science. Source for the finding that establishment depends on the size of the founder population and that below a threshold it simply fails.
• [92] Moerkens, R. et al. (2017). Inoculative release strategies of Macrolophus pygmaeus in tomato crops: population dynamics and dispersal. Journal of Plant Diseases and Protection 124:295-303. Source for the six to eight weeks of supplementary feeding and for the finding that the longer food is provided the more slowly the population disperses.
• [93] Schafer, L. and Herz, A. (2020). Suitability of European Trichogramma species as biocontrol agents against Tuta absoluta. Insects 11:357. Source for the finding that three European Trichogramma species were as effective as the commercial T. achaeae in laboratory trials.
• [94] Sarmah, N. et al. (2021). dsRNA mediated pest management of Tuta absoluta is compatible with its biological control agent Nesidiocoris tenuis. Insects 12:274. Source for the compatibility of new technologies with N. tenuis. Work with Greek participation, Agricultural University of Athens.
• [95] Bienkowski, A. and Orlova-Bienkowskaja, M. (2020). Rigorous morphological studies confirm that Chilocorus kuwanae is the same species as Ch. renipustulatus. Insects 11:368. Source for the finding that decades of releases in Europe were in fact releasing a native species, which shows what a misidentification costs.
• [96] UC Statewide IPM Program. California red scale and yellow scale. Pest Management Guidelines: Citrus, University of California. Source for the Aphytis melinus release rates: 100,000 individuals per 4,047 square metres per year in orchards under transition, individual releases of 5,000 to 10,000 per 4,047 square metres every two weeks with a seasonal split of 50 percent in spring, 25 percent in summer and 25 percent in autumn, and 10,000 to 40,000 per 4,047 square metres per year in southern California and in coastal areas.