Friend or Foe Part 2

Kathryn Wadsworth

Kathryn Wadsworth

Yesterday David and I taught an all day long Master Gardener class about insects. What fun! Insects come in so many different colors, sizes, and shapes it boggles the mind. Some insects (the good bugs) are a gardener’s friend and some (the bad bugs) are foes. Learning how to identify friend from foe really helps in successful garden management. Your friends are the beneficial insects, the predators, parasites, or pollinators. Predators and parasites eat the insects that ruin your garden and pollinators pollinate the flowers on your fruit trees and vegetables. The list below is a continuation from David’s last blog posted on Monday, January 18.

           Butterflies and Moths. All of these insects belong to the order Lepidoptera, meaning scale-wing, because their wings are covered with minute, often colorful scales. Adults have four large wings and are often much appreciated for their grace and beauty. Their larvae, on the other hand, are caterpillars, cutworms, hornworms, corn earworms, tomato fruitworms, and many other very destructive pests of our food crops and ornamental plants. All lepidopterans have complete metamorphosis with larvae that are worm-like caterpillars which pupate in a chrysalis, cocoon, or in the soil. The larvae have chewing mouthparts and the adults have straw-like mouthparts for sucking up nectar.

Caterpillars come in many different colors and sizes. Some are very furry, some are quite smooth. Some are brightly colored and some match their background so perfectly they are very difficult to find.

Caterpillars come in many different colors and sizes. Some are very furry, some are quite smooth. Some are brightly colored and some match their background so perfectly they are very difficult to find.

The adult butterfly exhibits the features of both butterflies and moths. Most moths are active at night and most butterflies are active in the daytime.

The adult butterfly exhibits the features of both butterflies and moths. Most moths are active at night and most butterflies are active in the daytime.

Adult grasshoppers have well-developed wings.

Adult grasshoppers have well-developed wings.

Grasshoppers. These insects belong to the order Orthoptera, meaning straight wing. The order also includes the cockroach, praying mantis, and cricket. Adults of some species have four large, often membranous wings while other species have very small wings, or no  wings at all. These insects have incomplete metamorphosis. Their young are nymphs that resemble miniature adults without wings. Nymphs and adults have chewing mouthparts and eat the same food. Of all the insects in this order, grasshoppers and locusts are perhaps the most destructive.

Baby grasshoppers, or nymphs, resemble adults but their wings are undeveloped.

Baby grasshoppers, or nymphs, resemble adults but their wings are undeveloped.

Thrips. Thrips are insects in the order Thysanoptera, meaning fringe wing, because their four slender wings are fringed with tiny hair-like projections. Thrips are extremely small insects, long and slender, often very hard to see with the naked eye. Thrips have incomplete metamorphosis. The nymphs resemble the adults but have no wings. They have rasping and sucking mouthparts and nymphs and adults are often found feeding together on their host plants. Thrips nymphs, like the adults, rasp away the surface tissue of plants leaving telltale patches of silvery dead cells behind. Adult thrips can fly but are not strong fliers. If you suspect a thrips infestation, hold paper under the suspect plant and tap the plant. If thrips are present they will fall onto the paper.

Aphid nymphs look much like the adult aphids except for the lack of wings.

Aphid nymphs look much like the adult aphids except for the lack of wings.

Aphids, Leafhoppers, Psyllids, Whitefly, Scale, and Adelgids. All of these insects belong to the order Homoptera, meaning whole wing. They have four membranous wings. All are plant eaters and many are quite destructive. Most are readily identifiable as insects, but scale and adelgids look more like bumps or cotton wads than insects. They have incomplete metamorphosis. The nymphs in some species resemble miniature adults without wings. In other species the nymphs  are quite different in appearance and are called “crawlers.” All have piercing/sucking mouthparts. Many are sedentary as adults, sitting in one spot with their beaks inserted into a plant’s vein while they suck out the life-giving sap. They often occur in large numbers in colonies.

Winged aphid adults appear late in the season to mate and lay eggs for the next generation the following year.

Winged aphid adults appear late in the season to mate and lay eggs for the next generation the following year.

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