Integrated Pest Management

Thrips continue to be a problem through the summer months. They can infest a variety of flowering plants including hibiscus, hydrangea, and roses. Continue to look for signs of damage such as curled leaves, stunted growth, and white streaks on the foliage. Monitor your plants with a simple beat test. Tap the branch onto a sheet of white paper and look for small, thin, brown or orange thrips on the paper. Five or more thrips per beat may warrant spraying with an insecticide labeled for thrips, but first look closely for signs of the minute pirate bug, a natural predator of thrips. These small, black insects feed on thrips and also on pollen, so look for them on the flowers.

Beware of yellow jacket nests in the ground. These insects are beneficial when they feed on insect pests and are important pollinators, but when drought shrinks their food supply, they become dependent on trash, food crumbs, and sweet liquids found around our homes. They defend their food sources by stinging repeatedly at the slightest provocation. Keep your living areas clean of food debris and keep your trash and food containers covered.

Take the time to inspect your pine trees for pine sawflies. The larvae are an inch long and yellow-green with black dots. They consume all of the needles on a single branch before moving on to the next one. Small trees can be completely defoliated in a few days, so check them often. These insects are easy to remove by hand since they feed in groups. Horticultural oil can be used if the infestation is severe.

August is the time to monitor your garden for the presence of Oriental beetles. In the larval stage, the white grubs can be very damaging to plants as they feed on the roots of annuals, perennials, shrubs, and trees. Very similar to the Japanese beetle grub, the grub of the Oriental beetle can be identified by the pattern of bristles on the underside of the abdomen. Oriental beetle grubs have two straight lines of bristles; in Japanese beetles they appear in a “V” shape. You can monitor for the grubs by first observing the appearance of your plants. Oriental beetle grubs prefer plants indigenous to Asia such as flowering cherries and Chinese elm. Observe these plants for signs of stunted growth, which is the result of a loss of feeder roots. In the fall, look for grubs in the top few inches of soil. If there are more than a few per square foot, you may want to consider treating the area with a pesticide to control the grubs in the coming spring.

Be on the lookout for the Asian longhorned beetle. Native to China, the beetles were first spotted in Brooklyn, NY in 1997. They have since been detected in nearly every other state with port facilities. The large white grubs of this beetle feed on the heartwood of a variety of trees including maple, horsechestnut, boxelder, poplar, black locust, white mulberry, willow, and elm. They are particularly fond of sugar maple. The adult beetle can be seen from July to September and is easy to spot. The adult is an inch or more in length, glossy black with white spots, and long black and white segmented antennae. Besides the unmistakable appearance of the adult, look for signs on your trees such as sap flow, large holes, and sawdust. If you think you have spotted this pest, notify your state department of agriculture immediately.

Mid to late August is a good time to plant your salad greens such as lettuce and spinach. The shorter days and cooler nights of late summer and early fall make ideal conditions for a second crop of these cool season vegetables. The summer heat and drought conditions we’re experiencing this year have reduced the slug populations, so damage from these slimy pests should be minimal.

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