 | Field and Forage Crops |
 | Ornamentals and Turf |
From: Jack Bacheler, Extension Entomologist
On the morning of May 23, first true leaf cotton in untreated check plots in our thrips tests near Rocky Mount were already showing significant damage. Based on hand lens observations, thrips levels seem to be moderate to high. We planted these tests three weeks ago on May 2. At this point, all of the seed treatments (sprayed yesterday) and Temik plots looked fair to good. With our generally cool nights, cotton seedlings have been “growing off” slowly. Much of the early planted seed-treated cotton in the middle and southeastern parts of the state is now showing 1 to 3 true leaves and has already been sprayed for thrips.
So far, this year is more like 2006 than 2007 in terms of moisture, so we hope that once day and night time temperatures warm up, seedling “grow-off” conditions will improve. As is often the case, mid to late April-planted cotton can be expected to take much more of a beating from thrips than cotton planted after the first week in May. As we have advised in the past, try to spray all cotton following seed treatments with a foliar application for thrips within three weeks of planting or at the first true leaf stage. With our generally high thrips levels and slow “grow-off” conditions, this approach almost always pays of itself.
All other thrips treatment decisions either following Temik or after any previous foliar spray for thrips should be based on scouting. Focus these efforts on finding immature thrips in the bud area. Because individuals vary in their ability to find thrips, the use of a hand lens or beating some cotton seedlings onto a flat object or into a flat small box is advised. The finding of even 1 to 2 immature thrips per plant in the bud area and/or upper terminal of 1 to 2 true leaf cotton usually means that reproduction is underway and treatment is indicated. If scouting is thorough, 3 and 4 leaf cotton can probably tolerate an average of 3 to 4 or so more immature thrips per plant without economic loss.
From today’s forecast, it looks like we may be in for some mid to high 80 degree days beginning early next week to help push our young crop to the thrips-safe 5 to 6 true leaf stage. However, if hot weather arrives without rainfall, expect even greater levels of adult thrips migrating into cotton from drying hosts. In years past, the last week in May and the first week in June has been crunch time for thrips.
From: Steve Bambara, Extension Entomologist
I normally don't see this often, but within the last two weeks I've received two reports of cottony camellia scales (image by Anne Edwards) on holly from coastal counties, so I thought it was worth mentioning. The "cottony" scales can be fairly obvious with their nicely extruded cottony egg sacs. Cottony camellia scale certainly occurs on camellia, but also on holly (Ilex) and a few other hosts. Though it is found on other parts of the plant, one characteristic is how it tends to line up along the margins of the leaf on the underside. Crawlers should be present now, or soon. For information on some common pests of holly, see Ornamentals and Turf Insect Note No. 141 at: http://www.ces.ncsu.edu/depts/ent/notes/O&T/specificplants/note143/note143.html.
This scale is similar to the more famous cottony cushion scale that we are also seeing now and is famous on Pittosporum and Nandina. See Ornamentals and Turf Insect Note No. 51 on the web at http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note51/note51.html for information on cottony cushion scales.
Oak treehoppers, Platycotis vittata, feed gregariously on oaks throughout the eastern United States. These insects are somewhat closely related to leafhoppers, but tend to be larger and to have the forward part of the thorax variously modified into bumps and spines. The oak treehopper is unusual in that there is a white with red and black markings form (image by Steve Bambara) and a dull brown or green form. They are undoubtedly Darth Vader's favorite insect. This insect overwinters as females who lay their eggs the following spring. When the eggs hatch, the new nymphs gather around a slit in the bark made by the female. The nymphs apparently feed at the slit and the female "broods" over them. The nymphs have two tiny "horns" on their backs and they tend to be contrastingly marked with white, black and red. Oak treehoppers are usually of little importance to shade trees. Most of the contact pesticides will give adequate control of oak treehoppers, but usually there is no need to control these critters.
The hackberry woolly aphid is a fluffy little creature (image by P. M. Choate, University of Florida) that can produce a lot of honey dew and subsequent black sooty mold fungus. You don't want to park beneath one of the infested hackberrry trees. Populations of this aphid, Shivaphis celti, may vary from year to year, but once they find your tree, they will probably be there every year. If you do not have much hackberry (Celtis) in your landscape, you may not have noticed. There doesn't seem to be any long term damage to the trees. The University of Florida has a helpful insect note on the web (http://creatures.ifas.ufl.edu/trees/asian_hackberry.htm) if you want additional information.
The ash borer is one of the clearwing moths that resemble a wasp as an adult. They overwinter as late instar larvae in the wood, usually nearer to the base of the plant. They pupate in the stems (image by Dan Wall) and emerge as adults in May/June, roughly. Heavily damaged trees and shrubs should be removed. Preventive bark sprays may help in May and June. The May 21, 2004 issue of North Carolina Pest News (http://ipm.ncsu.edu/current_ipm/04PestNews/04News6/ornament.html) has a list of some homeowner borer sprays. Virginia Tech University has an insect note about this borer at http://www.ext.vt.edu/pubs/entomology/444-278/444-278.html.
This week I received some nice photos of periodical cicadas (1, 2, 3, 4, 5, 6) (images by Bobby Ward) from Weaverville, North Carolina. I thought you might enjoy them. They are courtesy of Mr. Bobby Ward. Plan your trip to the mountains now.
The net-winged lycid beetle (image from Steve Bambara), in the family Lycidae, is related to lightning bugs. There is not much information about them. They are not pests, but are reported to eat fungi and may be found emerging from mulch, and around wooded areas. This group of beetles is said to be "bad tasting", but so far that goes untested in our lab.
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 24, 2008 by Stephen J. Toth, Jr.
