Saturday, July 27, 2013

Pest Alert for Week of July 29th


From: Steve Frank, Extension Entomologist

Debris-carrying Green Lacewing Larvae are Active and Everywhere!

Green lacewing larvae are common predators of several soft-bodied pest arthropods across the United States. Their prey includes but is not limited to: scale insects, spider mites, aphids, thrips, and eggs of pest insects. They are useful in biological control because of their generalist and voracious feeding habits. Lacewing larvae are often compared to alligators due to their elongate, slender body shape and are typically yellow and brown in color with six legs. These larvae have large pincer mouthparts that they use to penetrate bodies of prey, paralyze them, and literally suck out their insides. They use these mouthparts to devour several hundred prey per week. Lacewings are known to be cannibalistic if they cannot find any other food source. This is one reason that they deposit their eggs individually on long hairs that suspend them above the leaf surface out of reach. These eggs are common and can be easily found on leaf surfaces. 

Some, but not all green lacewing larvae, develop a camouflage cover which hides them from predation by other insects. These are called debris-carrying lacewing larvae because they pick up plant tissue debris and other insect debris and attach it to their back. This camouflage makes them difficult to recognize by natural enemies and the inexperienced human eye. Often times they will appear to be a cluster of tree lichen until you notice small legs underneath or it start to move. They can currently be found on most plants just by scanning leaf surfaces. I have seen several recently without looking for them. These insects remain larvae for two to four weeks at which point they develop into winged green lacewing adults. Adult lacewings are not predators and primarily feed on plant nectar. The adults are commonly attracted to lights at night and can often be found around your home.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.