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From: Jack Bacheler, Extension Entomologist
Through May 16, cotton planting is now approaching 70 percent completion. So far, it seems like we are experiencing one of those cooler, wetter springs for cotton, but only slightly. Weather is predicted to be generally on the moderate side this coming week, so we could use some of those high 80/low 90 degree highs to get seedlings off and running and to narrow the time window of vulnerability to thrips damage. Most fields that have cotton coming up appear to be headed toward decent stands.
Although moderate temperatures and adequate soil moisture so far appear to be steering us toward a more reasonable thrips year compared with 2007, this situation could change in about a week to 10 days if we experience continuous hot, dry conditions. At least for the coming week, this is does not appear likely.
Producers should be reminded again that the most vulnerable time for thrips damage is between the expanded cotyledon to the second true leaf stage. Although Roundup Ready Flex cotton has taken the pressure off of having to apply two glyphosate applications prior to the fifth true leaf stage, remember that a foliar application for thrips alone is almost always economically justified at three weeks after planting or at the first true leaf stage following seed treatments, even though these treatments increase the risk of spider mite and cotton aphid outbreaks.
On the positive side, as we approach May 20, cotton planted after this date often reduces the odds of having significant thrips damage. So for cotton planted after this time, replanted or otherwise, count on either a seed treatment or a 3 to 4 pound rate of Temik without a foliar application to take care of thrips under most circumstances.
We have not received reports of cutworms or other pests causing damage yet, but the time we expect cotton seedling insects to show their hand will likely be during the next three weeks.
Hopefully, by this time next week, we’ll begin to gain an appreciation of how the early part of the growing season is shaping up.
From: Steve Bambara, Extension Entomologist
An outbreak of earwigs (image by James R. Baker) was recently reported from Randolph County. In a severe infestation, earwigs may nibble on tender foliage of vegetable or bedding plants. They do not bite or sting. Mostly, they are just annoying or repulsive to homeowners. Our damp spring has probably been helpful to them. If you are earwig-intolerant, they are vulnerable to most pesticides labeled for a particular site.
The following is what Dr. David Shetlar at Ohio State University tells folks in the Buckeye state:
"The European earwig overwinters in the adult stage, usually in the soil, under rocks or landscape timbers and in thick mulch. In [early spring], females enlarge a chamber in the soil or under rocks or logs and deposit a clutch of eggs. The females clean and move the eggs periodically. Within a couple of weeks, the tiny earwig nymphs hatch and the female opens up a small burrow to the soil surface. The tiny nymphs forage on warmer nights on insects and soft plant materials, especially emerging seedlings. Each day, the nymphs return to the burrow which is protected by the parent. “When the nymphs are about half grown, usually in mid-May to early June, they are too large to fit into the original nest and they often begin to disperse. This is the time that observant gardeners begin to see groups of earwigs clustering under flaps of loose bark on tree trunks, in the petals of flowers, or under flower pots left on the porch."
If you are an azalea lace bug hater, you might consider treating now. Lace bugs cause a blotched or spotted appearance of the upper leaf surface (image by James R. Baker), however, immature (nymph) and adult lace bugs are found mostly on the underside of leaves. Severely infested leaves turn yellow and may drop off prematurely. They normally do not kill a plant, so it is often just a cosmetic decision.
Spots of excrement resembling dark varnish are a distinguishing characteristic and appear on the underside of the leaves (image by James R. Baker). Female lace bugs lay groups of eggs on the underside of leaves, most often along the midrib. These eggs are dark colored and are partially inserted into the leaf tissue or are pale and completely hidden inside the leaf. Dark, spiny nymphs hatch from the eggs. If you choose to use a spray, be sure to spray the underside of the leaves.
Adult rhododendron borers active in May and June, are small black moths with white and yellow markings (image by John W. Neal, Jr.). These moths lay their eggs on the bark of rhododendrons, azaleas, and mountain laurels. Tiny caterpillars hatch from the eggs, bore into the sapwood, and develop into inch-long "worms." The boring by the caterpillars may cause the stem to wilt. If the stem is large enough it may not wilt. However, sometimes the first indication of rhododendron borer infestation is that the stem breaks off. Pruning and destroying heavily-infested parts of the plants is component of the management for this pest.
It seems worthwhile at this time to remind everyone of what a lady beetle (aka ladybug) looks like. Okay, you think they are all small half-round beetles with spots. You're mostly correct, but you also need to recognize the immature stages. We are now seeing all stages in the landscape. Lady beetle larvae are highly predaceous on aphids, mites and other tiny insects just as the adults are.
The eggs of some common lady beetles are yellow and less than 1/16 inch in length. They are often laid on end in small groups. From the eggs, hatch larvae (image by James R. Baker). These are small insects that resemble tiny, short-snouted alligators with six legs. Some lady beetles have larvae covered with a fluffy white secretion (image by James R. Baker) which makes the insect look like a mealybug. The next stage is the pupa (image by Steve Bambara). Pupae are about the size of the adults, but the legs and antennae are closely pressed to the body. Also, the wing buds wrap around the body. The pupae are usually anchored to the substrate at the rear. Lady beetle pupae do not resemble the adults (or anything else in the home gardener's experience). Consequently, these pupae are sometimes squashed or scraped off and destroyed. Each lady beetle larva eats many aphids and other pests, and each lady beetle lays many eggs which potentially hatch into many more larvae. The pupae . . . well, they just sit there.
Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.
Last modified on May 17, 2008 by Stephen J. Toth, Jr.
