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Finding the Good Guys

If you invite me to your garden for a tour, I probably won't be looking at your flowers, but rather start turning over leaves or inspecting holes, looking for the insects that may reside there. Several clues will prompt me to inspect a plant, like frass (insect poop), holes in the leaves, yellowing, speckling and poor growing tips. The investigation doesn't stop until several leaves and flowers have been inspected. This investigation, known as scouting, is a weekly check for the first signs of insect pests, which allows gardeners to make management decisions when the populations are low.

In most gardens there are the common culprits like aphids, whitefly, spider mites, cucumber beetle, flea beetle, squash bugs, cabbage caterpillars and tomato hornworms.

Once I have located the garden pest, I will start looking for what other insects may be eating these detested garden intruders. These good bugs are welcomed by most gardeners, since they provide biological pest control in exchange for a nectar and pollen source from the flowers and a reduction in the chemicals used. Most are rarely identified.

If aphids are found in the garden, there may be a host of good bugs already hard at work.

Most often found when scouting is lady bug larvae. They look like small spiders when they first hatch, and in their later larval stage they look like little spiky black alligators with bright spots. The larvae and adult of a lady bug will eat thousands of aphids in its lifetime.

Aphid lions can be found dining on aphids in its larva lifecycle, as well as mealy bugs, spider mites, leaf hopper nymphs, scale, whitefly and numerous insect eggs. Aphid lions are the larvae of green lacewing and look more like a green alligator with sickle-shaped jaws than a lion. Green lacewing adults feed on pollen and nectar at dusk and will eat honey dew (aphid poop).

Aphids also can be attacked by small wasps. If the aphid body becomes papery, brown and blown-up looking, it has wasp larvae growing on the inside. Wasps also are parasites on tomato hornworms, which remain paralyzed but alive while the wasp larvae feed. They look like multiple white sacs attached to the body of the tomato hornworm. This non-stinging parasitic wasp family controls imported cabbage worms, caterpillars, flea beetles and squash bugs.

Garden pests hit with parasites should remain on the plant to ensure future populations. Adult wasps need pollen and nectar from small flowers like sweet alyssum.

Acceptance of some pests is crucial to keep good bug populations thriving