Identifying Insect Culprits

Perennials

Class 1: Some Perennials Basics
Class 2: Garden Design
Class 3: Putting Pencil to Paper
Class 4: Soil Preparation and Planting
Class 5: Maintaining your Perennial Gardens
Class 6: Troubleshooting

Insect pests vary from region to region, and even season to season. There are hundreds of insect species in the average garden, and most are either beneficial or benign. A reference book or field guide is indispensable when it comes to identifying insects you find in your garden. Only a small percentage warrant a gardener’s concern, and it’s critical to be able to distinguish friends from foes. Here are some guidelines for inspecting plants for signs of insect attack.

First of all, you don’t need to inspect plants leaf by leaf. There are a few key places on plants where insects like to feed or hide. Here are some things to look for:

1. Examine the youngest shoots on the plant. Some pests, such as aphids, tend to cluster on the succulent new growth. And many insects prefer to nibble on tender new growth rather than older, tougher leaves.

2. Many insects hide out on the undersides of the leaves. Turn the leaves over slowly, or the insects may fly away or drop to the ground before you get a good look. Examine the undersides of the leaves for round or barrel-shaped egg masses. Some insect species lay their eggs in distinctive pattern, so this can help you identify whether these eggs are from "good guys" or "bad guys."

3. Pay close attention to the type of damage you see. Are the margins of the leaves nibbled? Are there holes in the center of the leaf? Are they small and round? Irregularly shaped? Are the areas between the veins eaten away, leaving the leaf "skeletonized?" Noting these details can help you determine the culprit.

Many insects move more slowly in the cool of the morning, so this is a good time to do your inspections -- it will be easier to observe and capture fast-moving insects. Others, like slugs and cutworms, are active at night, so keep a flashlight handy! Make careful note of what you find, then use these observations to help you identify the insects you find, or to determine what is causing any damage you see.

Class 6, Page 1 2 3 4 5 6 7

Insecticidal soap and horticultural oil are two of the safest pesticide products.

Insecticidal soap is helpful in controlling soft-bodied insects such as aphids. For good control, you may need to reapply the soap several times, 3 to 7 days apart.

Horticultural oils are mineral- or vegetable-based oils that smother insects and insect eggs. Avoid applying oils on hot days, and follow mixing and application instructions carefully to avoid damaging plants.