Bugs that Eat Bugs

Garden Clippings for June 17, 2017

In the animal world sharks are on the top of the food chain.  On land, it is probably the lion, hawk or giraffe that make it to the top.

In the insect world climbing to the top of the food chain is not that easy.  Entomologists have not spent much effort in researching the issue, probably because the world didn’t care enough.

But in the last few decades we have seen a renewed interest in researching the life and times of lowly insects.   We now use far less insecticides than in the era of our parents and grandparents, and we are learning more about insects that eat insects.

Lady bugs are cute creatures that do a big service to gardeners by reducing aphid populations.  Aphids are small critters, about 1/8 of an inch long, in green, black, brown, grey, or shades of red.  Aphids and will usually be found on the ends of the newest green leaves of a host of shrubs, trees, perennials, annuals and roses.   Hungry aphids will suck the sap from tender foliage causing the host leaves to become stunted or distorted.  Fortunately damage caused by aphids is rarely fatal.

The other interesting by-product of aphid damage is sooty mold, a black fungus that grows on aphids’ excretions.  Initially we see sticky shiny residue on foliage, followed by the formation of black fungus resembling soot.  The best way to control sooty mold is to control the aphids that cause it.

Lady beetles are readily available for purchase anytime from June to September.  They can be ordered on-line or are available at select garden retailers.  Expect to pay about $25.00 for 1,000 ladybugs.

Nematodes are now the preferred control measure for June Bugs, Japanese Beetles, and European Chafers.  Nematodes are tiny living organisms that creep through the soil in search of grubs.  Nematodes can be applied anytime grubs are present but the optimum time is the end of August into September, soon after the adults have laid eggs.  Soil needs to be damp for nematodes to travel.

Lacewings are pretty green winged insects that feed on aphids, mealybugs, spider mites whiteflies and scales.

Praying Mantis is a general predator that feeds on a wide range of pests including aphids, Colorado potato beetles, hornworms, chinch bugs and many caterpillars.  Praying Mantis are shipped in an egg case that will open when they are ready, about the middle of June.  Watching Praying Mantis hatch is a wonderful biology lesson for kids.  They quickly disperse, hide, claim a territory and find dinner.

We have long known that good bugs are useful to control bad bugs.  It is safe to say that we can expect to see more beneficial insects available in the future as research continues and demand increases.