The greenish worm is probably the pear slug. The pear slug is not an actual slug. It’s the larval stage of an insect (sawfly). The pear slug feeds on pear, cherry, plum, and several other woody plants.
Ash trees infected with emerald ash borer (EAB) do not need to be treated or chipped when removed. If you do plan to keep the wood for campfires or fireplaces use it on your property and do not transport the wood to new locations. Any…
The Colorado potato beetle is difficult to control. Hand picking is a control option for individuals with small gardens. Hand-pick beetles, eggs, and small larvae from infested plants as soon as possible (practical for a few insects…
Cabbageworms are greenish caterpillars that eat large, irregular holes in the foliage of cabbage, broccoli, cauliflower, and Brussel sprouts. Cabbageworms can be controlled with biological or chemical insecticides. Bacillus…
Mealybugs on houseplants are difficult to control. Unless the plant is particularly valuable, it’s often best to throw away the infested plant before the insects spread to other houseplants. The standard remedies for houseplant pests…
Two closely related insect pests, the asparagus beetle and the spotted asparagus beetle, occasionally attack asparagus plantings in Iowa. When asparagus shoots appear in spring, these beetles emerge from their sheltered, overwintering locations…
Female cicadas lay eggs on small twigs and the damage can cause some twig die-back (also called flagging). For a large tree this is not a concern, but if possible you can protect small or high value trees and shrubs.
The green “worms” are the larvae of the azalea sawfly. The larvae are green, smooth, and up to one inch long. They feed along the edges of the azalea leaves. After feeding, oftentimes only the midvein of the leaf and leaf…
Greenbug aphids may be responsible for the brownish orange color of the turfgrass. Greenbug aphids feed only on plants of the grass family (Kentucky bluegrass, corn, sorghum, etc.). Greenbugs live on the grass blades and feed on sap…
Oedema is probably responsible for the lesions on the undersides of the ivy geranium leaves. Oedema is not caused by an insect or disease pathogen. It is a physiological problem. Oedema is most often encountered in greenhouses…
The foam-like masses in the dogwoods were probably created by the dogwood spittlebug. The dogwood spittlebug is one of several species of this commonly recognized group of sap-feeding insects. Spittlebugs are familiar because of the…
The small, black beetles are likely sap beetles. They are also known as picnic beetles or picnic bugs. Sap beetles commonly feed on overripe or damaged fruits and vegetables in the garden.
The tiny holes are likely due to flea beetles. Flea beetles are the most common pest of eggplant in the home garden. Adults are tiny, shiny, black beetles. They possess large hind legs that enable them to jump. Flea…
The large, hard growth is probably crown gall. Crown gall is caused by the bacterium Agrobacterium tumefaciens. The bacterial disease can infect roses, grapes, apples, raspberries, willows, euonymus, and many other woody…
The foam-like masses on the strawberry plants were probably created by the meadow spittlebug. The meadow spittlebug is one of several species of this commonly recognized group of sap-feeding insects. Spittlebugs are familiar because…
The growths on the pin oak are a type of gall. Galls are abnormal growths of plant tissue induced to form by mites, insects, or other small organisms. The galls on the pin oak are called horned oak galls because of the horn-like…
The yellow-green bugs are probably the adults of the northern corn rootworm. The larvae of the northern corn rootworm feed on the roots of corn plants. The adults (yellow-green beetles) appear in mid-summer and are present until frost…
The Emerald Ash Borer (EAB) is an exotic destructive pest that kills all native ash trees (Fraxinus). The loss of ash trees significantly impacts the urban tree canopy. While treatment options are available, some trees cannot be treated…
It’s likely the pile of sawdust-like material was produced by carpenter ants. Carpenter ants commonly nest inside older, hollow trees or in trees with dead limbs or branches. Carpenter ants do not eat wood. However, they…
Periodical cicadas emerge in 13- or 17-year cycles depending on the brood. These broods emerge in specific geographic regions. Occasionally, two broods will emerge in the same year, and more rarely, there can be some overlap in the geographic…
Noticeable symptoms of emerald ash borer usually appear in the second or third year of the infestation or later. Emerald ash borer infested trees exhibit thinning of the leaf canopy and dieback in the crown. Also, infested ash trees…
The main objective in spraying apple trees is to prevent insect damage to the fruit. The most important period to spray apple trees is from petal drop until just prior to harvest. Several applications will need to be made during this…
