Aphids, Leaf hoppers and lacebugs

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Aphids, leaf hoppers, and lace bugs are plentiful this wet spring because of all the lush succulent growth. This flush of growth is ideal for these sap feeders that insert their mouthparts into the food conducting tissues of the plant and suck out sugars and cellulose. Generally, low populations of these garden visitors do not harm the plants as natural predators feast on them.

Large populations could give a gardener pause because they do suck plant juices creating a sticky substance known as honey dew, lay eggs and sometimes spread disease. In the case of potato leaf hopper, large populations can cause damage to crops known as hopper burn. Hopper burn occurs when these particular hoppers destroy the plant conducting tissues while feeding leaving behind curling, stunting and brown leaves. While most populations do not harm plants, these insects can be fascinating when scouting the garden.

Aphids are small pear shaped insects that have cornicles (tail pipes to excrete honey dew) and can come in colors ranging from the bright yellow ones found on milkweed to green ones on the underside of a tomato leaf. At this time of the year, all aphids are female and give live birth to pregnant clone daughters. A typical female aphid can give birth to five daughters a day. One of the biggest issues with aphids is sometimes a black sooty mold grows on their honey dew.

Leaf hoppers are slender with angular head that come in a multitude of colors in order to blend in with the environment. They live in shrubs, grasses and flowers and most extract cell contents leaving only white dots. In the past week, I have seen several nymphs that look like they have tuft of white cotton attached and jump rather far when disturbed. This white tuft is called flocculent and scientists believe it reduces moisture loss and provides protection from predators.

Lace bugs look like tiny pieces of lace and prefer feeding on asters, sunflowers and goldenrods. Their frass (excrement) is strategically placed along the vein and secures the eggs to the leaf. They congregate while they are young nymphs on the underside of the leaves.

A solution is to live with these pests and let nature handle their high populations. These insects have many natural enemies, including lady beetles, lacewings, damsel bugs, and spiders. They are also subject to diseases and parasitic wasps that help keep their numbers down under most conditions.

Sometimes just a hard water spray from the hose is enough to knock off the pests from the plants without even using chemicals. Search your garden this weekend to find your garden pests and the garden warriors that feast on them. If you need help identifying the insects or plant issues visit the McLean County Master Gardener Help Desk at uiemg-mclean@illinois.edu or 309-663-8306.