Biological pest control works, but only when the right beneficial is matched to the right pest. Releasing a predatory mite against aphids, or a parasitic wasp against spider mites, won't get you anywhere. Every beneficial insect, mite, and nematode in Koppert's lineup has been developed for specific pests, specific life stages, and specific conditions.
This guide breaks down the most common pests you'll encounter and explains which biological agents work against them, how each one operates, and why the match makes sense. Whether you're managing a greenhouse, a vegetable garden, or an indoor plant collection, this is your starting point for building a program that works.
Thrips
Thrips are among the most challenging pests in horticulture. Western flower thrips (Frankliniella occidentalis), onion thrips (Thrips tabaci), and Echinothrips (Echinothrips americanus) are the most common species in Canadian growing environments. They feed by piercing plant cells and sucking out the contents, leaving behind silvery scarring, distorted growth, and — in the case of western flower thrips — transmitting Tomato spotted wilt virus (TSWV), one of the most economically damaging plant viruses in greenhouse production.
What makes thrips particularly difficult is their life cycle. Adults and larvae feed on foliage, but some pre-pupal and pupal stages, depending on thrips species, drop to the soil or grow medium to complete development underground. Eggs are always laid in the leaf tissue. Effective biological control requires a layered approach — targeting thrips at multiple life stages simultaneously.
Amblyseius swirskii (Swirski Ulti-mite), Neoseiulus cucumeris (Thripex), and Amblydromalus limonicus (Limonica)
The above are predatory mites and the primary tools for preventative thrips management. Only choose one, as they intraguild predate, but each feeds on thrips eggs protruding from leaf tissue and first-instar larvae (the earliest, most vulnerable stages). By targeting thrips at this point, the predatory mite reduces the chance of a second generation establishing. Swirski and Limonica also feed on whitefly eggs and larvae, making them a genuinely versatile preventative mite. Available in slow-release sachets for long-term establishment.
Orius insidiosus (Thripor)
Orius is a predatory bug, not a mite, and it's significantly more aggressive than predatory mites against thrips. It feeds on all mobile thrips stages, including adults, making it an elimination agent rather than just a preventative. Orius uses its piercing mouthparts to puncture and consume thrips directly.
Stratiolaelaps scimitus (Entomite-M) or Steinernema feltiae (Entonem)
Entomite-M and Entonem target the soil-dwelling pupal stages of thrips. The stage that predatory foliar mites simply cannot reach. A surface application of Stratiolaelaps scimitus or a soil drench with Steinernema feltiae interrupts the thrips life cycle at the point where it's most vulnerable and least treated. Applied per our guidelines through the crop cycle in the growing medium, either product provides season-long suppression of soil-stage thrips. Combine with Swirskii or Thripor on the foliage for a two-stage approach that covers the full life cycle.
Chrysoperla carnea (Chrysopa)
Green lacewing larvae are generalist predators and will feed on thrips larvae when present, though they aren't a dedicated thrips control agent in the way Orius or Swirskii are. In mixed pest situations where thrips, aphids, and other soft-bodied insects are all present, or where unique thrips are located, like in tropical houseplants, Chrysopa functions as a useful supplementary predator.
Aphids
Aphids are sap-sucking insects that reproduce at alarming speeds. A single aphid can produce dozens of offspring per week through parthenogenesis, meaning populations can double in days under favorable conditions. They cluster on new growth and stem tips, excreting sticky honeydew that promotes sooty mold and attracts other pests. Species vary considerably: green peach aphid (Myzus persicae), foxglove aphid (Aulacorthum solani), and cotton aphid (Aphis gossypii) are among those covered on our pest pages. Each species has different host preferences and susceptibility to specific biological agents — species identification matters here.
Aphid biological control works best as a combination strategy. Predatory insects consume aphids directly; parasitoid wasps lay eggs inside living aphids, killing them from within. Using both together provides faster and more durable suppression than alone.
Chrysoperla carnea (Chrysopa)
Lacewing larvae are voracious aphid predators; hence the nickname 'aphid lions.' They use hollow, fang-like mouthparts to pierce aphids and extract the contents through extraoral digestion. A single larva consumes 300–400 aphids over its development. They're active hunters, dispersing across the plant canopy in search of prey, and they work well alongside parasitoid wasps.
Coleomegilla maculata (Coleobug) and Adalia bipunctata (Aphidalia)
Coleobug and Aphidalia are native North American ladybird (ladybug) species. Both adults and larvae are predatory, feeding directly on aphid colonies. Coleomegilla maculata is an omnivore — it also feeds on pollen — which helps it persist on plants even when aphid populations are temporarily low, maintaining a resident predator population ready to respond when numbers climb again.
Aphidalia larval and adult stages also consume aphids entirely. It's particularly effective at working through dense aphid colonies on stems and leaf undersides. Best used in combination with parasitoid wasps for a layered approach.
Aphidius colemani (Aphipar), Aphidius matricariae (Aphipar-M), Aphidius ervi (Ervipar)
These are parasitoid wasps that target aphid species. Here is where aphid identification matters. Aphidius colemani and Aphidius matricariae attack smaller aphid species, including the green peach aphid and the cotton aphid. The female wasp detects aphids using chemical cues, lands on the aphid, and inserts an egg directly into its body. The wasp larva develops inside the living aphid, eventually killing it and leaving behind a characteristic bronze, mummified 'aphid shell.' These mummies are a reliable indicator that the biological program is working.
Aphidius ervi targets larger aphid species, primarily the potato aphid and foxglove aphid. These species are not well controlled by Aphipar or Aphipar-M, making Ervipar the specific tool for those host species. Same parasitization mechanism: egg inserted into living aphid, larva develops inside, mummy left behind.
Parasitic wasps work best preventatively; introduce early before aphid populations establish. They combine well with a predatory insect or gall midge for a predator-parasitoid combination that hits aphids through two distinct mechanisms simultaneously.
Aphidoletes aphidimyza (Aphidend)
Aphidend is a gall midge (not a wasp or beetle), whose larvae are specialized aphid predators. The female midge is attracted to honeydew produced by aphid colonies, lays her eggs among the aphids, and the hatching larvae inject a paralyzing toxin before consuming them. A single larva can kill far more aphids than it eats. It paralyzes prey indiscriminately. Aphidend works particularly well in greenhouse environments where the adults can fly freely to locate aphid colonies.
Spider Mites
Two-spotted spider mite (Tetranychus urticae) is the primary spider mite pest in Canadian greenhouses and gardens, though broad mite, false spider mite, hemp russet mite, and spruce spider mite are also covered in our pest library. Spider mites feed on the underside of leaves, piercing cells and causing characteristic stippling (tiny pale dots across the leaf surface) followed by bronzing, visible webbing, and in severe infestations, leaf drop. They thrive in hot, dry conditions and populations can explode rapidly when those conditions are met.
Phytoseiulus persimilis (Spidex)
Persimilis is a specialist predator. It feeds almost exclusively on Tetranychus spider mites, which makes it highly effective but also means it requires an active mite population to sustain itself. It's a fast-moving, aggressive predator that consumes spider mites at all life stages. The best product for hot spots.
Neoseiulus californicus (Spical)
Californicus is a more flexible spider mite predator than persimilis. It tolerates lower prey densities, and it can feed on pollen and other food sources when spider mite numbers are low, which makes it an excellent preventative option. Spical Ulti-mite sachets release Neoseiulus californicus continuously over 4–5 weeks, establishing a resident predator population before pest pressure builds. It also tolerates a wider temperature range than persimilis.
Feltiella acarisuga (Spidend)
Spidend is a gall midge whose larvae are specialist spider mite predators. The adult midge is highly mobile and can fly through a greenhouse to locate spider mite hotspots, then lay eggs directly in the mite colony. The larvae feed aggressively on all spider mite stages. Feltiella works particularly well as a complement to predatory mites in situations where mite colonies are established and dispersed across a large area.
Beetle Larvae, Cricket Larvae, Shore Fly Larvae, Crane Fly Larvae & Caterpillars
This group of pests are linked here not because they're the same pest, but because they share a common biological control solution: Steinernema carpocapsae.
Steinernema carpocapsae (Capsanem)
Capsanem is an entomopathogenic nematode. A microscopic, soil-dwelling roundworm that carries symbiotic bacteria (Xenorhabdus nematophila) inside its gut. It's an ambush hunter: infective juveniles wait near the soil surface for mobile prey to pass, then enter through natural body openings. Once inside the host, they release their bacterial payload directly into the bloodstream, causing fatal septicemia within 24–72 hours.
Against caterpillars, Capsanem can be applied as a foliar spray, targeting caterpillars feeding on plant tissue before they drop to the soil to pupate. Against crane fly larvae (leatherjackets) and black vine weevil larvae, soil drench applications targeting the root zone are standard. Apply to moist soil at temperatures between 10–30°C, and water in thoroughly after application to move nematodes to root depth.
White Grubs
White grubs are the soil-dwelling larvae of scarab beetles. June beetles, European chafer, and Japanese beetle are the primary species in Canada. They are C-shaped, creamy white, and feed on plant roots underground, causing wilting and plant death that appears suddenly above ground. In turf, grub damage appears as irregular brown patches that lift away from the ground because the root system has been severed.
Heterorhabditis bacteriophora (Larvanem)
Larvanem is the nematode specifically developed for white grub control. Unlike Capsanem, Heterorhabditis bacteriophora is a cruiser. It actively moves through the soil profile following chemical gradients to locate sedentary prey. It carries Photorhabdus bacteria, which it releases into the grub's bloodstream to cause fatal infection. It performs best at soil temperatures above 15°C, with optimal activity above 20°C. Application timing is critical: treat in spring when grubs are near the surface, or in late summer when the current year's hatch is still in early, most susceptible instars. Older, larger third-instar grubs are significantly harder to control.
Mealybugs
The citrus mealybug (Planococcus citri) and long-tailed mealybug (Pseudococcus longispinus) are among the most difficult pests to control chemically. Their waxy, water-repellent coating protects them from contact sprays, and they hide in leaf axils, stem junctions, and root zones where products struggle to penetrate. They feed on plant sap and excrete honeydew, promoting sooty mold. In indoor plant collections and greenhouses, populations can build quickly in warm, sheltered microclimates.
Cryptolaemus montrouzieri (Cryptobug (L))
Cryptobug (L) is a predatory ladybird beetle specifically developed for mealybug control. Both adults and larvae are predatory. They physically push through the waxy mealybug coating to reach the soft body beneath, something most chemical sprays can't do effectively without high-pressure application. One important note: Cryptolaemus larvae are covered in white, waxy filaments and closely resemble mealybug crawlers in appearance. This can cause confusion during crop monitoring; mark your release points so you don't mistake your beneficials for the pest.
Leaf Miners
Leaf miners (primarily Liriomyza species) are fly larvae that feed between the upper and lower surfaces of leaves, creating the characteristic pale, winding tunnels visible on the leaf surface. Adults lay eggs in leaf tissue; larvae mine through the leaf mesophyll before dropping to pupate in the soil. Damage is both direct, reducing photosynthetic capacity, and indirect, as entry wounds create infection sites for fungal pathogens.
Diglyphus isaea (Miglyphus)
Miglyphus contains Diglyphus isaea, a parasitoid wasp that targets leaf miner larvae inside the leaf. Unlike typical parasitoid wasps that lay an egg inside the host, Diglyphus is an ectoparasitoid: the female paralyzes the leaf miner larva, then lays her egg beside it within the mine. The wasp larva feeds on the paralyzed miner externally. Females also directly kill leaf miner larvae through host feeding (consuming them without laying an egg), which means their impact on the pest population is immediate and doesn't depend solely on the next wasp generation hatching. Miglyphus works best in warm conditions (above 15°C) with good light levels.
Whitefly
Greenhouse whitefly (Trialeurodes vaporariorum) and tobacco whitefly (Bemisia tabaci) are major pests in protected growing environments. Adults are small, white-winged insects that fly up in clouds when disturbed; larval instars are flat, scale-like, and feed on the underside of leaves. Both species excrete honeydew and can transmit plant viruses. Tobacco whiteflies are a more aggressive species and harder to control, with a broader host range and greater pesticide resistance. Identifying which species you're dealing with matters when selecting biological agents.
Encarsia formosa (En-Strip)
En-Strip contains Encarsia formosa, the classic parasitoid wasp for greenhouse whitefly control. One of the oldest commercially used biological control agents in horticulture, with a track record going back decades. Encarsia is an endoparasitoid: the female lays a single egg inside a whitefly larva, and the wasp larva develops inside, killing the host. Parasitized larvae turn black, making monitoring straightforward. En-Strip cards are hung in the crop canopy, releasing wasps continuously. Encarsia is most effective against greenhouse whitefly; it's less effective against tobacco whitefly.
Eretmocerus eremicus (Ercal)
Ercal contains Eretmocerus eremicus, a parasitoid wasp with a different host interaction. Rather than laying directly inside the nymph, Eretmocerus females lay their egg beneath the whitefly larva; the larva burrows in after hatching. This species is effective against both greenhouse whitefly and tobacco whitefly, making it the preferred choice when Bemisia is present or suspected. It also tolerates higher temperatures than Encarsia. In practice, combining En-Strip and Ercal (Enermix) provides broader coverage across both whitefly species and a wider range of conditions.
Fungus Gnats
Fungus gnats (Bradysia species) are one of the most common pests in indoor growing environments, greenhouses, and container production. Adults are small, dark-bodied flies that resemble tiny mosquitoes — they're mostly harmless on their own, though their presence is a reliable indicator of a larval problem below the soil surface. It's the larvae that cause real damage. They feed on organic matter, root hairs, and young roots in the growing medium, stunting plant growth and creating entry wounds for root pathogens like Pythium and Fusarium. In seedling production and propagation, fungus gnat larvae can cause significant losses quickly.
Steinernema feltiae (Entonem)
Entonem contains Steinernema feltiae, an entomopathogenic nematode and the primary biological control agent for fungus gnat larvae. It's applied as a soil drench directly into the growing medium, where infective juveniles actively seek out and enter fungus gnat larvae, releasing their symbiotic Xenorhabdus bacteria to cause fatal infection within 24–72 hours. Apply to moist growing medium and water in after application to move nematodes through the root zone.
Stratiolaelaps scimitus (Entomite-M)
Entomite-M is the soil-dwelling predatory mite Stratiolaelaps scimitus. It feeds on fungus gnat eggs and early instar larvae in the growing medium, making it a strong complementary agent alongside Entonem. A single application at the start of the crop cycle provides season-long suppression. The combination of Entonem and Entomite-M (nematodes targeting larvae, mites targeting eggs and larvae) covers the soil-stage life cycle comprehensively and is the recommended approach for high-pressure situations.
Building Your Program
The most effective biological control programs layer multiple agents targeting the same pest at different life stages or target multiple pests simultaneously with compatible products. No single beneficial insect solves every problem, but the right combination, introduced at the right time and maintained consistently, can keep pest populations in balance throughout an entire growing season.
For more detail on any pest or beneficial insect listed in this guide, visit the Koppert Canada Pest Information and Beneficial Insects pages. And if you're unsure where to start, our crop protection guides walk through recommended programs for specific growing environments.
