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From: Stephen B. Bambara and Michael G. Waldvogel, Extension Entomologists
We have received a few telephone calls from worried people that chiggers may be taking over the planet. Okay, that's an exaggeration. What is true is that millions of tiny red mites, about the size of a sand grain are being seen crawling around outdoors, up foundation walls and sometimes coming inside around windows and doors. While we first suspect clover mites during the cool season, Erythraeid mites (image by Steve Bambara) may instead be the culprit. They do not have the extremely long front legs that you see on clover mites (you can read about clover mites in Ornamental and Turf Insect Note No. 124 at http://insects.ncsu.edu/O&T/lawn/note124/note124.html).
Although they are not "vegetarians" as are the clover mites, they are not likely to bite people. Most (all?) Erythraeids start out as parasites of insects. The older instar nymphs and adults are predaceous on a variety of insects. That's about the major difference between Erythraeid and clover mites because they may both be a nuisance to non-mite-lovers. Pesticide applications are not really necessary, unless one's tolerance for mites is lower than spraying poison all around the premise. Any of the common pesticides can be applied to the foundation and surrounding soil (about 2 to 3 feet out) preferably with a garden hose sprayer, but without knowing that you've pinpointed all of the sources, you could find out that they are actually coming “down” (for example from moist areas under roof shingles) whereby spraying the foundation obviously has no effect.
With clover mites, the problem usually abates in about a week or so. Erythraeid mites may continue for over a month. The best advice may be to not sit down outdoors if you are wearing white clothing.
From: Stephen B. Bambara and Christine A. Casey, Extension Entomologists
Oak Sower Gall
The wool sower gall is a distinct and unusual plant growth induced by the secretions of the grubs of a tiny gall wasp, Callirhytis seminator. If a fresh wool sower gall is held in a plastic bag out of the sun (so it will not get too hot), within one to three weeks the tiny, harmless gall wasps will emerge. The wool sower gall is specific to white oak and only occurs in the spring. Pulling the gall apart exposes small seed-like structures. The gall wasp grubs develop inside these structures. (This gall is also called the oak seed gall.) Fortunately, wool sower galls are hardly ever abundant enough to cause harm to white oaks. If the galls are actually damaging the trees, the best time to control them is mid-winter when the wasps are laying their eggs or spring just as the buds are breaking. The eggs hatch just as the new growth emerges in the spring. Ornamentals and Turf Insect Note No. 5, which provides information on galls, is available on the web at http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note05/note05.html.
Oak Apple Gall
Large oak-apple gall wasps form galls on the leaves or leaf petioles of various red, black and scarlet oaks. These galls are up to two inches in diameter, are green tinged with red when fresh, and gradually turn brown. For information on other oak galls, see the May 14, 1999 North Carolina Pest News article on the web at: http://ipm.ncsu.edu/current_ipm/99PestNews/99News4/ornament.html.
We haven't been good predictors of insect activity so far this spring, but plants that typically suffer from spruce spider mite and southern red mite should be checked now for activity. During the active period is the best time to treat. Horticultural oils work great. Professionals have several additional compounds from which to choose. See Ornamental and Turf Insect Note No. 77 at http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/ort077e/ort077e.htm.
Azalea lace bugs are out and growing. Now is probably to the time for most of you to do any spring treatments if you haven't already. The azalea lace bug is among the most frequently reported insect pest in the landscape. Lace bugs feed by inserting their needle-like mouthparts into leaves and injecting saliva. When the lace bug sucks out the predigested fluid, the empty cells left behind are conspicuously pale. After what appears to be a short time, lace bugs cause the leaves to become completely bleached and have a bronzed appearance on the upper leaf surface. Lace bugs also leave shiny, black excrement (fly specks) on the lower leaf surface (image from James R. Baker). Azalea lace bugs are relatively difficult to completely eliminate. Fortunately, they rarely kill plants.
Insecticidal soap can control small populations or Orthene may be used for control if pressure is high. Most other landscape shrub insecticides will also work, but read the label first. Be sure to treat the undersides of the leaves. Imidacloprid can be used as a foliar spray or soil drench in specimen or small, valuable plantings. The azalea plant bug, Rhinocapsis vanduzeii, is a predatory bug that can provide some azalea lace bug reduction when used in conjunction with insecticidal soap. Azaleas planted in full sun are said to suffer more than those planted in partial sun. Ornamentals and Turf Insect Note No. 39 contains additional information on the azalea and other lace bugs (see http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/ort039e/ort039e.htm).
At work I park my car under oak trees to avoid the sap from when I park under the Leyland cypress hedge. During the last two weeks, however, the honeydew from the scale insects above makes a sticky mess of my windshield at the end of the day when I head home. At least I take a little satisfaction that the honeydew lands on the Mercedes, too.
Sometime soon, the eggs from the parthenolecanium scale (formerly known as a lecanium scale) (image from Steve Bambara) will be hatching and crawlers will emerge from under the protective scale. Now comes the big decision. Is it worth doing anything or should one just wait it out for a few more weeks? It takes a very severe infestation to impact an oak tree. Treatment requiring spraying a tree is expensive, even with inexpensive horticultural oil. The alternatives of trunk injection or soil injection are not inexpensive and come with their own set of hazards. I think I'll just keep my windshield washer reservoir full and wait for rain. If it were my tree, I'd try to reduce as many environmental stresses on it as possible. For more information, see Ornamental and Turf Insect Note No. 36 at http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note36/note36.html.
There are still some bees showing up in lawns. Currently we are seeing some Andrenids (image by Steve Bambara). These are a little smaller than a honey bee. They are not prone to sting and are only active for a few weeks. They nest in individual holes in the lawn (image by Steve Bambara), often on a slope. For more information on ground nesting bees and their possible control, see Ornamental and Turf Insect Note No. 100 at http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note100/note100.html.
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Last modified on April 30, 2007 by Stephen J. Toth, Jr.
