from the wild side
Trichogramma wasp Trichogramma spp.
IDENTIFICATION — Trichogramma wasps are parasitoids that kill other insects before the insects can even hatch. Although this seems like something from a horror movie, these creatures are garden-friendly because they don’t harm plants at all — just the insects that eat them!
Trichogramma are some of the smallest known insects at less than 1/50 in. long — four or five of them can fit on the head of a pin. Their stocky bodies range in color from yellow to brown, and they have raspberry-colored eyes, short antennae and hair-fringed wings.
LIFE CYCLE — These wasps have a unique life cycle. The female (which doesn’t need a male to reproduce) locates a moth or caterpillar egg by sight and smell. Then she injects it with her own eggs and a venom that is thought to kill and digest the pest embryo inside. One to four wasps can grow and develop inside the egg, feeding on the predigested embryo and egg yolk. A parasitized insect egg will usually turn black.
Trichogramma wasps live almost everywhere. They are the insects most widely used for pest control in the world, targeting the eggs of more than 200 pest species, including hornworms, fruit worms, cutworms, codling moths and corn borers.
HOW TO ATTRACT — Next summer, having trichogramma in your garden will help reduce the pest population and protect your plants from munching bugs. You can keep these mini wasps around by reducing pesticide use. And grow tiny flowers, like fennel, caraway, tansy and Queen Anne’s lace as nectar and pollen sources for adults.
If you’re having a problem with boring insects in your garden, you can buy trichogramma wasps from online sources like Buglogical Control Systems (www.buglogical.com) or Gardens Alive! (www.gardensalive.com).