SLEEPING WITH THE ENEMY

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More familiar too many of us are the paper, or social, wasps. These include the various species of hornets and yellow jackets, all of which are insect predators. They range in size from 1/2" to 1" or more in length, and, unlike the solitary mud dauber, they create large, highly organized colonies, which they fiercely defend. Treat any foraging wasps with quiet respect and you should be able to work side by side.

Adults also require pollen and are particularly fond of flowers from the daisy family. Oxeye daisies, strawflowers, black-eyed Susan, and even goldenrod and yarrow will draw predatory wasps to your garden. Ripe fruits and berries are irresistible to them.

OTHER BENEFICIAL BUGS New forms of predatory and parasitic bugs are being discovered and experimented with every day. There may well never be an end to the possibilities, as insects on both sides of the bug wars continue to adapt and change. Three more that are fairly new weapons in the biogardener's defense arsenal are encarsia formosa, beneficial nematodes, and predatory mites.

Encarsia Formosa Most often recommended for greenhouse whitefly control, this tiny wasp is native to most of North America and can be established in home gardens. Adults are only about 1/40" long. Almost every one is a female, capable of producing more females without bothering with a male. They do best in temperatures over 70°F, and what they do best is consume whiteflies — nothing but.

Once they have done in up to 90% of the pest's population, their own numbers will decline if not given a little help. If used inside a greenhouse, lower the temperature below 70°F. and remove any whitefly traps. (You may want to leave one in place to monitor whitefly numbers.) A few whiteflies can't do any real damage and are essential to the survival of the parasites.

Place a few leaves infested with whiteflies and the parasites next to a rose geranium plant. Substances given off by the geranium cause the metabolism of both species to slow. Many people have had success overwintering the parasites in this way, then releasing them into the greenhouse or garden the following spring

A Nematode worm investigating the
back of a meal mite. Some 80,000
species of Nematodes are known

Nematodes

Not too long ago, any gardener familiar with these unseen creatures could tell you that nothing good could possibly follow that word. Insidious, destructive, and relentless, it's precisely those same lovely qualities that make beneficial nematodes so endearing.

Almost any insect pest that spends any time at all on or beneath the ground is vulnerable to attack by the tiny insect parasites Neoplectana carpocapsae and Heterorhabditis heliothidis. In the soil, these nematodes hunt down borers, root weevils, cutworms, beetle larvae, cabbage roots maggots, wireworms, and much more.

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