Thrips - Several samples of field corn have come into the lab with extensive thrips damage on the leaves including yellowing and white-flecking on the leaves. Thrips are usually associated with hot dry weather but these are correlated with cool wet weather which has slowed the plant growth down and allowed the thrips to get a good foothold. Several years back I received a number of thrips damaged corn plants during a cool wet spring. The corn plants should be able to outgrow the thrips damage once good corn growing conditions return.
Sap Beetles - Many times injured spots on field and sweet corn will be invaded by small sap beetles. The most common of these beetles in Virginia is the Dusky Sap Beetle which is about 1/4 inch in length with a clubbed antenna and wing covers that do not cover its entire abdomen. It is dark brown in color. This beetle will infest old borer or earworm entry sites, hail damage, or any type of wound. They will infest usually after some rot has started. They will also get into many other types of fruits and vegetables, peaches and tomatoes to name a couple.
Japanese beetles have NOT been observed flying in the Blacksburg area yet but should be flying in all parts of Virginia soon. Japanese Beetle traps placed about 40 feet from grapes or fruit trees should help reduce the damage to those plants.
Earwigs - June is earwig time and all the rain the last few months has left a lot of moist organic matter for them to breed. Reduce and thin mulch. Remove piles of leaves and wood from near the house.
Buck moths continue to grow and may be found moving from oak tree to oak tree or in columns on the bark. Spot treat if objectionable damage is found and avoid touching.
Woolly alder aphids are found on Silver Maple now in large colonies on the underside of leaves. They are conspicuous for their large tufts of cottony wax on their backs giving the whole colony a "linty" look.
Larger elm leaf beetles, which are large metallic green and orange beetles, are starting to show up on elm. Usually minor pests as they tend to be sporadic and not found every year. The years they do show up they can cause severe defoliation. Not to be confused with the (common) Elm leaf beetle.
Next month start looking for young caterpillars feeding the leaves of hardwood trees. Many caterpillars such as oakworms, mapleworms, fall webworms, and azalea caterpillars will be getting started in July and are easy to control when they are small (less then 1/2 inch).
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