Beneficial Insects

Lady Bird Beetles (Cocconellidae)

Lady bird beetles, commonly referred to as ladybugs, are among the most recognizable predatory beetles. Both adult beetles and larvae are voracious generalist predators of soft-bodied insect pests.

• Target Pests and Prey:
  • Generalist predator of aphids, soft scales, armored scale crawlers, mealybugs, whiteflies, spider mites, and small caterpillars.
• Description and Life Stages:
  • Adults: Oval, dome-shaped beetles (4-8 mm long), ranging in color from red to orange or yellow, usually with black spots. Common species include the Convergent Lady Beetle (Hippodamia convergens) and the Asian Lady Beetle (Harmonia axyridis).
  • Larvae: Elongated, spiky, dark gray-to-black body with bright orange or yellow lateral markings, often described as having an “alligator-like” shape.
  • Eggs: Bright yellow, spindle-shaped eggs laid in tight vertical clusters on leaf undersides near active pest colonies.
• Active Windows:
  • Most active in spring through autumn
    • Overwintered adults emerge in early spring (100-250 GDD) to feed and lay eggs near aphid outbreaks.
    • Multiple overlapping generations occur through October.
• Management & Conservation Strategy:
  • Conserve native populations by avoiding broad-spectrum foliar insecticide applications when larvae and adults are present in aphid colonies.
  • Maintain early-blooming nectar plants (i.e. dandelion, alyssum, and coreopsis) to feed emerging adults in early spring before pest populations build.
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Lady Bird Beetle Page. 
• Additional Resources & Extension Factsheets 

• • Common Backyard Beneficials – Plant & Pest Advisory
  • Landscape Pest Notes for April 2023 – Plant & Pest Advisory
  • Intercropping for Insect Pest Management – RCE
  • Insect Management with Low Fruit Load – Plant & Pest Advisory

Green and Brown Lacewings (Chrysoperla & Hemerobius spp.)

Lacewings are important generalist predators in nursery and landcape settings. Adult green lacewings feed primarily on nectar and honeydew, but their larvae are quite voracious predators that are equipped with curved, hollow jaws.

• Target Pests and Prey:
  • Generalist predator of aphids, spider mites, thrips, whiteflies, mealybugs, scale crawlers, insect eggs, and small caterpillars.
• Description and Life Stages:
  • Adults: Slender, pale green or brown bodies (12-20 mm long), with large, delicate, transparent wings and prominent gold-colored eyes.
  • Larvae: Cream-to-brown alligator-shaped larvae (8-10mm long) with sickle-shaped pincers used to pierce prey and suck out body fluids.
  • Eggs: Oval, white eggs suspended individually at the tips of slender, thread-like stalks (6-8mm long) attached to leaves.
• Active Windows:
  • Most active in late spring through fall:
    • Adults emerge in May (200-400 GDD). Females lay hundreds of stalked eggs near pest colonies.
    • Multiple generations develop through September.
• Management & Conservation Strategy:
  • Conserve native populations by avoiding broad-spectrum foliar insecticide applications when populations are detected.
  • Plant flowering umbels (dill, fennel, coriander, yarrow) to attract egg-laying adult females.
  • Green lacewing eggs and larvae are widely available commercially for release in greenhouse and high-value nursery container blocks.
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Lacewings Page. 
• Additional Resources & Extension Factsheets 

• • Common Backyard Beneficials – Plant & Pest Advisory
  • Landscape Pest Notes for Late June 2023

Flower Flies/Hover Flies (Syrphidae)

Hover flies, also called syrphid flies, are unique beneficial insects because they have a dual purpose: pollination, and pest control. The adult flies are valuable pollinators that hover over flowers like hummingbirds, and their larvae are highly effective aphid predators.

• Target Pests and Prey:
  • Specialized predators of aphids, soft scales, thrips, and small caterpillars.
• Description and Life Stages:
  • Adults: Yellow and black striped flies (8-12 mm long) that look like yellowjackets or bees, but have only two wings, exhibit their characteristic hovering flight behavior, and do not sting.
  • Larvae: Legless, translucent green to yellowish brown, maggots (10-15 mm long) that taper towards their heads. They grab apids and lift them off of the plant stem to consume them.
  • Eggs: Single, white, elongated eggs lay flat on leaf surfaces directly inside aphid colonies.
• Active Windows:
  • Most active in late spring through fall:
    • Adults appear in April and May (100-300 GDD) to feed on pollen and lay eggs.
    • Multiple generations develop through October.
• Management & Conservation Strategy:
  • Conserve native populations by avoiding broad-spectrum foliar insecticide applications when populations are detected.
  • Plant floral borders to provide the adult females with the pollen and nectar that they need to mature their eggs.
    • Sweet alyssum, buckwheat, and asteraceae flowers work especially well
  • Learn to distinguish the green syrphid larvae from pest caterpillars (syrphid larvae lack legs and distinct head capsules)
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Flower Fly Page
• Additional Resources & Extension Factsheets 

• • Common Backyard Beneficials – Plant & Pest Advisory
  • NJAES Beneficial Insects of the Home Garden

Predacious Mites (Phytoseiidae)

Predatory mites are essential natural predators for control of spider mites, rust mites, and thrips. Some notable species include Phytoseiulus persimilis, Neoseiulus californicus, and Typhlodromus pyri. They move much quicker than pest mite species.

• Target Pests and Prey:
  • Two-spotted spider mites, spruce spider mites, southern red mites, eriophyid rust nites, and thrips larvae
• Description and Life Stages:
  • Adults and Nymphs: Shiny, teardrop or oval shaped mites (0.5 mm long) that can range from pale yellow to bright reddish-orange. They have long legs and move very quickly across leaf undersides to search for prey.
  • Eggs: Oval white or translucent eggs, larger than pest mite eggs.
• Active Windows:
  • Most active in spring through fall:
    • Some species such as Neoseiulus californicus remain active across broad temperature ranges (50-90 F), and others can thrive only during specific seasonal windows.
• Management & Conservation Strategy:
  • Conserve native populations by avoiding broad-spectrum foliar insecticide applications, specifically pyrethroids (bifenthrin, permethrin) when populations are detected. Eliminating these sprays can prevent severe secondary spider mite outbreaks.
  • Inoculative releases of P. persimilis or N. californicus can provide fast biological control in greenhouse and container nursery stock.
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Predacious Mites Page. 
• Additional Resources & Extension Factsheets 
  • Common Backyard Beneficials – Plant & Pest Advisory
  • Predatory Mites – Cornell eCommons

Minute Pirate Bug (Orius insidiosus)

Minute Pirate Bugs are small, aggressive bugs with piercing-sucking mouthparts. The adults and the nymphs both feed on thrips and mites in nurseries and field crops.

• Target Pests and Prey:
  • Thrips, spider mites, aphid nymphs, whiteflies, insect eggs, caterpillars
• Description and Life Stages:
  • Adults: Very small (1.5-2mm), oval, black and white patterned bugs with triangular heads and prominent beaks.
  • Nymphs: Teardrop shaped, wingless, yellowish-orange to amber colored
  • Eggs: Very small (0.4 mm long), cream or white colored, and oblong shaped, with a flat, circular cap resting on top.
• Active Windows:
  • Most active in late spring through autumn
    • Overwintered adults emerge in May (300-500 GDD)
    • Populations build rapidly in summer heat, with generations completing every 15-20 days.
• Management & Conservation Strategy:
  • Conserve native populations by avoiding broad-spectrum foliar insecticide applications when larvae and adults are present in aphid colonies.
  • Plant alternate pollen for adults to feed on when pest populations are low
    • Alyssum, ornamental peppers, marigolds
  • Release commercial O. insidiosus in greenhouses or container blocks facing high thrips pressure.
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Minute Pirate Bug Page. 
• Additional Resources & Extension Factsheets 

• • UC IPM – Minute pirate bugs
  • Minute Pirate Bug and Insidious Flower Bug – Cornell CALS

Parasitoid Wasps and Flies

Parasitoids are specialized beneficial insects whose larvae develop inside or on a single host insect, ultimately killing it. This is a diverse group and includes microscopic wasps (Encarsia, Aphidius, Trichogramma) and tachinid flies.

• Target Pests and Prey:
  • Parasitic wasps: Aphids, armored and soft scale insects, whiteflies, wood-boring beetle larvae, and caterpillar eggs and larvae.
  • Tachinid flies: Caterpillars, sawfly larvae, stink bugs, and adult beetles.
• Description and Life Stages:
  • Parasitic wasps: Range from microscopic (~0.5mm Encarsia) to larger species (~20 mm Ichneumonids) with long ovipositors.
  • Tachinid Flies: Medium to large grayish black flies that resemble house flies, covered in stiff abdominal hairs.
  • Signs of Parasitism:
    • Aphid mummies: Swollen, rigid, tan or black hardened aphid shells with circular exit holes cut by emerging wasps
    • Scale exit holes: Tiny holes on mature scale covers, observable with a hand lens.
    • Tachinid eggs: Oval, white eggs stuck to the back of caterpillars or stink bugs.
• Active Windows:
  • Active in Spring through Fall, throughout the entire growing season.
    • Parasitoid life cycles are often synchronized with the life cycles of specific host insects.
• Management & Conservation Strategy:
  • Conduct field diagnostic checks before applying chemical controls for aphids or scales.
    • Inspect colonies with a hand lens.
    • If over 20% of aphids are mummified or scale covers have exit holes, delay spraying to allow parasitoids to suppress the population.
  • Plant small-sloweded umbelliferous plants (parsley family – yarrow, alyssum, buckwheat) to increase parasitoid longevity and egg production.
    • Adult parasitoids feed exclusively on floral nectar.
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Parasitoid Wasps and Flies Page. 
• Additional Resources & Extension Factsheets 

• • PPA: Parasitoids: The Hidden Backyard Beneficials
  • Common Backyard Beneficials – Plant & Pest Advisory
  • Plant Droplets Serve as Nutrient-Rich Food for Insects

Dragonflies (Anisoptera spp.)

Dragonflies are very powerful aerial predators in land management and aquatic ecosystems. They are not typically manipulated inside commercial greenhouses, but maintaining aquatic habitats near nursery field borders can support significant levels of natural control for landscape insect pests.

• Target Pests and Prey:
  • Adults: Flying insect pests, including mosquitoes, gnats, midges, flying aphids, winged scale crawlers, and moths.
  • Nymphs: Mosquito larvae, aquatic midge larvae, and larvae of other water-dwelling pests.
• Description and Life Stages:
  • Adults: Large, elongate insects with two pairs of wings that are held horizontally at rest, and large compound eyes.
  • Nymphs: Aquatic, robust, hinge-jawed predators living in retention ponds, irrigation basins, and natural waterways.
• Active Windows:
  • Active in late Spring through Fall
    • Nymphs develop aquatically for months to years.
    • Adults emerge in May through September, patrolling field borders and pond edges.
• Management & Conservation Strategy:
  • Avoid pesticide drift into nursery irrigation basins and retention ponds to protect aquatic dragonfly nymphs.
  • Retain tell emergent vegetation, reeds, and perimeter fence lines around nursery basins to provide hunting perches for adult dragonflies.
  • Important Regulatory Note: Always strictly adhere to product label guidelines. THE LABEL IS THE LAW. 
  • For more information, visit our Dragonflies Page
• Additional Resources & Extension Factsheets 

• • UConn: Beneficial Insects
  • Purdue: Who Let the Bugs Out?