Dozens of arthropod species feed on thrips, ranging from predatory mites smaller than a pinhead to lacewing larvae large enough to devour hundreds of thrips over their lifetime. Thrips are tiny, soft-bodied insects that damage crops by rasping plant cells, and their small size makes them vulnerable to a surprisingly diverse cast of natural enemies. Understanding which predators actually make a dent in thrips populations matters whether you grow greenhouse peppers or backyard tomatoes, because the right predator matched to the right situation can replace or reduce chemical sprays.
Predatory Mites
The most widely used biological control agents against thrips are predatory mites, particularly species in the family Phytoseiidae. These are the workhorses of commercial thrips management in greenhouses worldwide. Several species are reared in large numbers and sold commercially, each with slightly different strengths.
Amblyseius swirskii is one of the most popular choices. It feeds readily on the young larvae of both western flower thrips and onion thrips, attacking prey in under twenty minutes on a leaf surface and under ten minutes in confined spaces. Females lay roughly one egg per day when feeding on thrips larvae, and the mite completes its development from egg to adult in about eight days on a thrips diet.1Biocontrol Science and Technology. Prey suitability of western flower thrips, Frankliniella occidentalis, and onion thrips, Thrips tabaci, for the predatory mite Amblyseius swirskii In laboratory choice tests, A. swirskii consumed roughly 40 percent more onion thrips than western flower thrips when both were offered together, suggesting it has a mild preference between thrips species.2PubMed Central. Laboratory Investigations on the Potential Efficacy of Biological Control Agents on Two Thrips Species, Onion Thrips (Thrips tabaci Lindeman) and Western Flower Thrips (Frankliniella occidentalis (Pergande))
Neoseiulus cucumeris is another commercially available predatory mite often recommended for thrips control in flower and vegetable crops. It is typically released at around 50 mites per square meter per week, though research has shown that tripling or quadrupling that rate can suppress thrips larvae by 50 to 75 percent, a substantially better result than the standard rate.3Biological Control. Evaluation of efficacy of Neoseiulus cucumeris for control of western flower thrips in spring bedding crops The catch is cost: higher release rates mean buying more mites.
Amblyseius limonicus rounds out the top tier. Early comparative work found that it had the highest predation and egg-laying rates among several phytoseiid species when fed thrips larvae, and it also showed no tendency to enter diapause, meaning it stays active year-round in a warm greenhouse.4Entomologia Experimentalis et Applicata. Preselection of predatory mites to improve year‐round biological control of western flower thrips in greenhouse crops That continuous activity gives it an advantage in climates or growing systems where temperatures stay relatively stable.
Minute Pirate Bugs
If predatory mites are the foot soldiers of thrips control, minute pirate bugs in the genus Orius are the heavy hitters. These small true bugs, only a couple of millimeters long, are aggressive generalist predators with an outsized appetite for thrips. Unlike the mites, which mainly target young thrips larvae, Orius species can attack all life stages, including adults.
Orius insidiosus, common in North America, is the most studied species. In laboratory trials comparing predators of onion thrips and western flower thrips, O. insidiosus consumed twice as many onion thrips adults as western flower thrips adults in no-choice tests.2PubMed Central. Laboratory Investigations on the Potential Efficacy of Biological Control Agents on Two Thrips Species, Onion Thrips (Thrips tabaci Lindeman) and Western Flower Thrips (Frankliniella occidentalis (Pergande)) When given a choice between the two, though, the preference largely disappeared, suggesting these bugs are opportunistic feeders that will take whatever thrips are available.
A related Asian species, Orius sauteri, has been studied in detail for its lifetime consumption. Female O. sauteri can eat around 305 thrips over their lives, while males average about 104. Even the nymphs are voracious, with predation rates climbing steeply as they grow, reaching up to about 30 thrips per nymphal stage by the later instars.5Florida Entomologist. Predation Functional Response and Life Table Parameters of Orius sauteri (Hemiptera: Anthocoridae) Feeding on Megalurothrips usitatus (Thysanoptera: Thripidae) Those numbers give a sense of just how much damage a healthy Orius population can inflict on a thrips infestation over a growing season.
Orius laevigatus, widely used in European greenhouses, has an interesting distinction from predatory mites. Predatory mites are generally effective only against small thrips larvae, because larger larvae and adults are too big to attack. But O. laevigatus can kill thrips at every size. Research on virus-infected plants showed that while virus infection shortened the period when thrips larvae were vulnerable to predatory mites, it made no difference to predation by O. laevigatus, because the bug could handle larger thrips just fine.6PubMed Central. Herbivore benefits from vectoring plant virus through reduction of period of vulnerability to predation
Lacewing Larvae
Green lacewing larvae are sometimes called “aphid lions,” but they are far from picky eaters. Several lacewing species have proven effective against thrips in both laboratory and field settings. Their large jaws relative to body size and aggressive foraging behavior make them especially useful when thrips populations have grown beyond what mites alone can handle.
Chrysopa formosa, a lacewing found across Asia, demonstrated remarkable capacity in trials on cowpea fields. After release, its second-instar larvae consumed more than 71 percent of a mixed thrips population within two weeks. Under laboratory conditions, a single third-instar larva had a theoretical maximum predation of over 1,000 second-instar thrips nymphs.7PubMed Central. Laboratory and field suppression of cowpea thrips by Chrysopa formosa (Neuroptera: Chrysopidae) and predator viability at high temperature That “theoretical maximum” reflects what happens when prey are continuously available, which is unrealistic in the field, but the field results still showed significant suppression.
Lacewing larvae are not indiscriminate, though. When offered thrips of different life stages, the lacewing Mallada basalis consistently showed a strong preference for the youngest thrips larvae, moderate interest in pupae, and almost complete avoidance of second-instar thrips.8PubMed. Lacewing larvae (Mallada basalis; Neuroptera: Chrysopidae) as potential biocontrol agents against greenhouse thrips (Heliothrips haemorrhoidalis; Thysanoptera: Thripidae): stage-specific predation, prey stage preference, development, and survival This selectivity matters in practice: timing lacewing releases to coincide with peak emergence of young thrips larvae gives the best results.
Chrysoperla carnea, the most commonly available lacewing in commerce, has also been tested against thrips. In greenhouse trials on sweet pepper, it reduced tobacco thrips populations but was unable to completely eliminate them, a pattern typical of generalist predators working in isolation.9PubMed Central. Efficacy of natural enemies against the tobacco thrips Thrips parvispinus (Karny) in laboratory and greenhouse studies
Predatory Thrips
Among the more surprising entries on the list: some thrips eat other thrips. Several thrips species have evolved predatory lifestyles, feeding on mites, whiteflies, scale insects, and, critically, pest thrips species. Both facultative predators, which also eat plant material, and obligate predators, which feed primarily on other arthropods, exist within the order Thysanoptera.10PubMed. Thysanoptera as predators: their diversity and significance as biological control agents
The two genera that stand out for biocontrol are Scolothrips and Franklinothrips. Scolothrips species, sometimes called “sixspotted thrips” for the dark wing markings of one common species, are specialist predators of spider mites but will also feed on small thrips. Their populations respond strongly to temperature: the intrinsic rate of population increase for Scolothrips longicornis rises steadily from about 15°C up to 35°C, then crashes above 37°C.11ResearchGate / Journal of Economic Entomology. Effect of Temperature on Life Table Parameters of Predatory Thrips Scolothrips longicornis (Thysanoptera: Thripidae) Fed on Twospotted Spider Mites (Acari: Tetranychidae) That upper thermal limit is worth noting if you garden in hot climates.
Franklinothrips vespiformis, a wasp-mimicking predatory thrips, has been tested in commercial Ficus greenhouses, where it reduced tobacco thrips numbers but, like lacewings, could not eradicate the pest on its own.9PubMed Central. Efficacy of natural enemies against the tobacco thrips Thrips parvispinus (Karny) in laboratory and greenhouse studies Its ant-like appearance and active hunting behavior make it one of the more charismatic biocontrol options, if a thrips can be charismatic.
Hoverfly Larvae and Other Generalists
Hoverflies, the adults of which are often seen hovering motionless near flowers, have larvae that are underappreciated thrips predators. Molecular diet analysis of hoverfly larvae collected from Mediterranean lettuce crops detected western flower thrips DNA in their gut contents, confirming that field populations feed on thrips alongside their more commonly recognized prey, aphids.12PubMed. Molecular assessment of predation by hoverflies (Diptera: Syrphidae) in Mediterranean lettuce crops
In controlled experiments with the hoverfly Allograpta exotica, all three larval stages consumed both aphids and thrips. The second-instar larvae killed four times more thrips than aphids, even though they still showed a preference for aphids overall when both were offered together.13Entomologia Experimentalis et Applicata. Consumption and preference rates of the various larval stages of Allograpta exotica as biological control agents of Myzus persicae and Frankliniella gemina This dual-purpose capacity means hoverflies attracted to your garden for aphid control may already be helping with thrips as a bonus.
Big-eyed bugs (Geocoris species) are another generalist predator that includes thrips in their diet, though they rank thrips below aphids and whiteflies in preference. In trials with Geocoris ochropterus, the bugs consumed the most aphids per day, followed by whiteflies, with thrips last in the pecking order.14Journal of Current Science and Technology. Comparative prey predation ability of big-eyed bug Geocoris ochropterus (Fieber) (Hemiptera: Geocoridae) Big-eyed bugs are still useful as part of a broader predator community, but you would not rely on them as your primary thrips control.
Enemies Below the Soil Line
Many thrips species drop to the ground to pupate in the soil or leaf litter, and a different set of predators waits for them there. Soil-dwelling predatory mites in the families Laelapidae and Macrochelidae are the main players. These mites look and behave quite differently from the leaf-dwelling phytoseiids described earlier; they are generally larger, faster, and adapted to hunting in dark, humid soil environments.
Gaeolaelaps aculeifer is one of the best-studied soil predators of thrips. In citrus orchards, higher populations of this mite were linked to lower thrips numbers and less fruit damage, suggesting it plays a meaningful natural control role even without human intervention.15Biological Control. Soil-dwelling predatory mites in citrus: Their potential as natural enemies of thrips with special reference to Pezothrips kellyanus (Thysanoptera: Thripidae) Stratiolaelaps scimitus, often sold under the trade name Hypoaspis miles, is another commercially available soil mite that feeds on thrips pupae. Both species have been shown to prey on thrips pupae in laboratory trials, with G. aculeifer generally consuming more.16Journal of Asia-Pacific Entomology. Comparison of the predation capacities of two soil-dwelling predatory mites, Gaeolaelaps aculeifer and Stratiolaelaps scimitus (Acari: Laelapidae), on three thrips species
A third soil-dwelling predator, Macrocheles mammifer, showed even higher attack rates and shorter handling times than S. scimitus in comparative studies on bean flower thrips pupae.17Acarologia. Functional response of two soil-dwelling predatory mites, Macrocheles mammifer (Berlese) (Acari: Macrochelidae), and Stratiolaelaps scimitus (Womersley) (Acari: Laelapidae), on thrips Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae) The practical takeaway: combining leaf-dwelling predatory mites on the foliage with soil-dwelling mites below can attack thrips at two different life stages, making the overall control program more effective than targeting just one stage.
Entomopathogenic nematodes, which are microscopic worm-like organisms that infect and kill insect hosts, add another below-ground weapon. The nematode Heterorhabditis bacteriophora achieved up to about 88 percent mortality in thrips prepupae and 78 percent in pupae at high doses in the lab. In field trials on onion, H. bacteriophora-treated plots had dramatically fewer thrips than untreated controls, with larval counts dropping from roughly 30 to 44 per plant down to 5 to 10.18Biological Control. Potential use of entomopathogenic nematodes against the soil dwelling stages of onion thrips, Thrips tabaci Lindeman: Laboratory, greenhouse and field trials
Parasitoid Wasps
Parasitoid wasps kill thrips from the inside. The genus Ceranisus, in the family Eulophidae, includes tiny wasps that lay their eggs directly into young thrips larvae. The wasp larva develops within the thrips body, eventually killing it. Ceranisus menes is a solitary endoparasitoid known to parasitize several thrips species, including the widespread onion thrips.19Journal of Science Innovations and Nature of Earth. Biological control of Thrips tabaci on tomato crop by their parasitoid “Ceranisus menes” The female wasp targets early larval instars, and the parasitized thrips continues to feed for a while before the wasp larva completes its development and the thrips dies.
Parasitoid wasps tend to be slower-acting than predators because each wasp kills only one host per egg laid, and the killing is not immediate. They work best as a background mortality factor that keeps thrips populations from exploding rather than as a rapid knockdown tool. Commercial use of Ceranisus remains limited compared to predatory mites and Orius bugs, partly because mass-rearing the wasps is more difficult and partly because their impact is harder to see.
How Thrips Fight Back
Thrips are not passive victims. Even the larvae have defensive behaviors that reduce predator success rates. The most common defense is abdominal swinging: when a thrips larva detects a predatory mite approaching, it jerks its abdomen side to side to knock the mite away. Several thrips species, including western flower thrips and tobacco thrips, also produce anal droplets, sticky secretions from the tip of the abdomen that can gum up a predator’s mouthparts.20Biological Control. Predator-prey interactions: How thrips avoid predation
How effective are these defenses? When researchers anesthetized onion thrips larvae with carbon dioxide to prevent jerking and droplet production, predatory mite attack success increased markedly.21Entomologia Experimentalis et Applicata. How larvae of Thrips tabaci reduce the attack success of phytoseiid predators In normal conditions, a meaningful fraction of predator attacks fail because the thrips larva successfully repels the mite. This is one reason why predator-to-prey ratios matter: you need enough predators that some get through the defenses on every encounter.
Adult thrips add flight to their defensive toolkit. When disturbed, adults can simply fly away, which is why most predatory mites and many other small predators are far more effective against the wingless larval stages. The ability of Orius bugs to fly as well gives them a major advantage in pursuing adult thrips that other predators cannot match.
Keeping Predators Alive When You Also Spray
The biggest practical challenge in using natural enemies against thrips is pesticide compatibility. Broad-spectrum insecticides are devastating to predator populations. In pepper crops, broad-spectrum sprays reduced field Orius populations by up to 80 percent and increased predator mortality while decreasing their ability to eat thrips even when they survived.22Biological Control. Reduced-risk insecticides can effectively manage thrips without compromising Orius predation in pepper production Reduced-risk insecticides like cyantraniliprole and spirotetramat, by contrast, had minimal impact on Orius numbers. Some newer pesticides marketed as IPM-compatible have still proven harmful to predators like Orius armatus in Australian greenhouses, where failures to establish predator populations have been traced back to supposedly “safe” chemicals.23PubMed. Effect of new and old pesticides on Orius armatus (Gross) – an Australian predator of western flower thrips, Frankliniella occidentalis (Pergande)
If you plan to combine biological control with any sprays, the general rule is to check each specific product’s compatibility with each specific predator you are using. Labels saying “IPM-compatible” are not always reliable across all predator species.
Plants That Call for Help
Some plants essentially recruit their own bodyguards. When hot pepper plants were infested by western flower thrips, they released volatile chemicals, primarily methyl hexenoate and linalool, that simultaneously repelled incoming thrips and attracted their predator Orius laevigatus. The repellent effect on thrips peaked about six hours after infestation began, and the attraction of predatory bugs ramped up on a similar timeline.24Scientific Reports. Methyl hexenoate and linalool emitted by hot peppers repel western flower thrips (Frankliniella occidentalis) and attract their predator (Orius laevigatus) This kind of plant-mediated signaling means that growing certain companion plants near thrips-susceptible crops could help draw in predators naturally.
Banker plant systems take this idea further in greenhouses. These are plants maintained specifically to feed and house predators when pest populations are low. Black Pearl ornamental pepper, for instance, produces abundant pollen that sustains Orius insidiosus populations between thrips outbreaks, improving predator longevity, size, and abundance.25Biological Control. Pollen increases fitness and abundance of Orius insidiosus Say (Heteroptera: Anthocoridae) on banker plants Predatory mites like A. swirskii and A. limonicus similarly benefit from pollen-producing plants when thrips are scarce. The goal is to keep predator populations established and ready to respond when thrips numbers start to climb, rather than releasing new predators every time and hoping they arrive in time.
Why No Single Predator Is Enough
A recurring theme across all this research is that individual predator species reduce thrips populations but rarely eliminate them. Lacewings reduced thrips in field trials by over 70 percent but did not wipe them out. Predatory mites at standard rates may suppress thrips larvae by less than 50 percent. Even Orius, the most effective single predator, can be overwhelmed by rapid thrips reproduction in warm conditions.
The most successful commercial programs combine multiple predator types attacking different thrips life stages. A typical approach in greenhouse peppers or cucumbers might layer phytoseiid mites on the foliage to intercept young larvae, soil-dwelling mites or nematodes to kill pupae below ground, and Orius bugs as a cleanup crew for any adults that slip through. Banker plants keep Orius around during low-pest windows, and reduced-risk sprays handle outbreak peaks without wiping out the predator community. No single link in that chain is sufficient, but together they often keep thrips below the damage threshold without heavy reliance on broad-spectrum chemicals.