Differentiating the type of insect damage
The mouthparts of insects have adapted over time to suit the feeding style of each type of insect. Mouth parts differ from insect to insect, so the damage that they cause is useful in the classification and identification of the pest. Differentiating the type of insect damage will help you determine how to control the pest.
A chewing insect is any insect that has teeth. Most winged chewing insects (such as beetles, caterpillars and grasshoppers) feed only on leaf tissue, working from the leaf edge towards the center and eventually to the leaf stem. Crawling chewing insects, such as cutworms, will also eat roots and even stems of small plants.
Rasping insects (such as mites, snails, slugs and thrips) actually scrape off the surface of the leaves as sandpaper would. They suck up the fluids from the top layer of cells until all the green tissue has been consumed, leaving only the skeleton behind.
Sucking insects (such as aphids and whiteflies) have slender mouth parts with which they pierce leaves and stems to suck out plant fluids. Large populations can cause curling, yellowing and distortion of leaves, as well as stunting of shoots. Most sucking insects also produce large quantities of a sticky substance known as honeydew, which often turns black with the growth of a sooty mold fungus.
If you’re not sure what type of insect is attacking your plant, just bring in a sample and one of our nursery experts will recommend a remedy to help your plant.