Dealing with Summer Pests

By: David Bates

 

Summer pests are not limited to vacationing in-laws that don’t know when they’ve worn out their welcome.  With the typical arrival of summer conditions, what has also arrived are all the garden pests. Of course, not all bugs are bad. In fact, a garden with no bugs would be worrisome! A healthy garden will be well balanced with plants, bugs, and animals existing together and eating one another. Problems arise when this ecosystem is thrown off balance and someone eats more than their share. Practicing the methods of integrated pest management will help maintain a well-balanced garden.

 

The time to take aggressive action is when a particular pest is present in such high numbers that it threatens serious damage. Some pests you can expect to see this summer are aphids, mites, and bagworms. These guys can definitely inflict serious damage!

 

There are many types of aphids and they come in many different colors (green, yellow, brown, red, or black depending on the species and the plants they feed on.) All aphids are small, pear-shaped insects with long legs and antennae. Most have a pair of tube-like structures called cornicles projecting out of the hind end of their bodies. They pierce and suck sap from leaves, stems, and flowers, especially on fleshy new growth. You will almost always see them on the new growth of rose bushes. Their feeding can cause the growth to be stunted, discolored, and contorted. It can also reduce blooming and prevent buds from opening. During the growing season, spray aphids off plants with a forceful stream of water. This prevents populations from establishing. Also, rose aphids seem to be deterred by pungent under plantings of marigolds and/or garlic.

 

Mites are very tiny (about the size of a pinpoint) arachnids. They are not susceptible to insecticides because they are actually closely related to spiders. They will establish webbing in protected crevices on a plant, such as stem and leaf joints. These little guys may be difficult to see but the damage they cause is very evident and often serious. Like aphids, mites suck the juices from leaves, flower buds, and even stems of plants. The damage they cause is usually yellow speckling or spots on leaves but they may also cause bronzing, scorching and/or cellular distortion of plant tissue. The undersides of leaves will have tiny black dots where the mites have pierced the tissue. A good test for mites is to hold a white sheet of paper under the plant and lightly tap the plant. If little, slow crawling specks pepper the paper then you have mites. The best way to prevent an infestation is to keep your plants well watered and wash off the foliage. Mites prefer dry, hot conditions. It is best to water in the morning, especially when rinsing off foliage. Watering in midday can cause leaf burn and watering in the evening promotes fungal growth overnight.

 

Bagworms usually attack needle-leaved evergreens and spin their homes out of silk and bark and leaves. The final casing resembles a pinecone and is often mistaken for such because they primarily feed on cone bearing plants. The caterpillar (Thyridopteryx ephemeraeformis) hides inside the bag and pokes its head out the top to eat. It is amazing the damage these little guy can do! They can defoliate entire plants in no time, often killing evergreens. The best way to prevent infestation in a small yard is to hand pick and destroy all bags as soon as they appear. This can be done as long as there are not many bags present. Young bag worms (in bags less than 1/2") are susceptible to applications of BT (Bacillus thuringiensis kurstaki).

 

The key to effective control of any pest is early detection.  Take time to get in the habit of looking over suspect plants in you landscape.  Regardless of what part of the country you live or the plant material you have, there most certainly are pests to be mindful of.  Know you particular plant material.  Research likely pests that will be attracted to your garden.  Be prepared to take action…early.