Biocontrol Agents

Brown lacewings (Micromus variegatus)


Brown lacewings are a generalist predator of soft-bodied insects, particularly aphids.

Adults are 1.5cm long, brown, with large mottled brown wings, and long antennae.  The larvae are oblong, mottled brown, with large pincer-like mouthparts. Their appearance is often described as resembling that of an alligator.



Both the larvae and adults are predatory and each can consume 20-25 aphids per day. Adults are primarily nocturnal. Females can lay 100-150 eggs in her lifetime. Eggs are laid low in the plant, and larvae also preferentially forage lower in the plant. Brown lacewings will also feed on mealybugs and mites.

Recommendations for use

Brown lacewings are effective predators of several aphid species both when released alone and when released together with aphid parasitoids. One advantage compared to other generalist predator species, is their low developmental temperature threshold (as low as 4°C), allowing them to contribute to biological control of aphids under low temperature conditions (e.g. in early spring/winter).



  • Shipped as adults in bottles


Introduction rates

  • Preventative: 0.1 adult/m2
  • Curative:  1 adult/m2


Environmental considerations

  • Active from 4°C to 31°C, requires temperatures above 13°C for egg laying
  • Optimal conditions between 20°C to 31°C, 30% RH or higher
  • Diapause has not been reported in this species under greenhouse conditions



  • Both the adults and larvae are nocturnal and may be difficult to spot during the day
  • Shriveled carcasses of aphids are left behind after feeding


Factors affecting