The answer to this is, “it depends.” Time period within summer, weather conditions, amount of foliage and many other factors determine which bugs are foraging in your plants during the summer.
Aphids and scale never take a break from eating. That’s because they reproduce so fast that their progeny take over when the adults die off. Even if you can’t see them, you’ll know when you have aphids in your trees. Their waste material is a sweet, sticky honey dew that drops anywhere under an infested tree. I suggest that you clean driveways, sidewalks, patios and pool decks right away; the stuff can be messy. If your vehicle gets hit, it’s off to the car wash.
Although I haven’t seen it personally, arborists from other parts of the country have told me about ants farming aphids. When the population puts too much pressure on a tree, ants climb up, pick up some of the aphids and take them to another tree to establish a new colony. They do this because honey dew is a delicacy.
Although gypsy moths are pretty well under control in our area, they do pop up occasionally. Gypsy moths are finishing feasting on the leaves of any tree they have infested. Soon the caterpillars will travel down the tree to pupate. Fall cankerworm larvae, commonly called inch worms, are also finishing their feeding.
Some trees will soon begin hosting the fall webworm. Many property owners confuse this pest with the eastern tent caterpillar. You can tell the difference by placement of their tents, or webs. The fall webworm spins its webs on branch ends in late summer or early fall while the tent caterpillar spins its in the forks, or crotches, in the spring. This generation of tent caterpillar has completed its feeding cycle and is preparing to morph into egg laying adults.
While the emerald ash borer is in the news, the fact of the matter is that their larvae may be feasting inside your valuable ash tree(s). They won’t emerge until next spring.
When you look down instead of up, you may see small, moth-like bugs hovering over your lawn. These are sod webworm adults. When you see them, they are searching for places to lay their eggs. It is their larvae that feed on the succulent base of grass plants.
In August, grubs may again come to dinner in your lawn. If you have seen June bugs flying around, slamming into your windows, you had better check for grubs toward the end of summer. Just cut one-foot square pieces of sod at different places in your yard. Peel the sod back and count the number of grubs, if any. If there are more than eight or more in each area, you should treat for them.
An IPM (integrated pest management) program takes the burden of identifying and deciding on treatment options from your shoulders and puts it on an entomologist or IPM professional’s shoulder. Each pest must be treated differently. They have to be monitored so that the most effective treatment, or preventive, is applied at the optimum time in the pest’s life cycle and the results are monitored to be sure we have control. I certainly am happy that agriculture researchers developed this process, and that we have been able to adapt it.