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Ornamentals and Turf |
Let's be realistic. Whether it is praying or preying, how good are these insects? The preying mantis has a good reputation as a beneficial insect. But this insect is a generalist and will consume any insect that passes within it's reach, whether syrphid fly, leaf beetle or even other mantids. It would be more desirable to classify it as neither beneficial nor harmful. How about helpful? Should one spend money to release them in a garden? Well, that's up to you. They are interesting insects.
Peachtree borers are caterpillars of a clearwinged moth. The moths resemble wasps, but of course the moths do not sting. These moths emerge throughout the growing season, but the vast majority of them are in flight between August 15 and September 15. Consequently, most of the borers can be managed preventively by spraying esfenvalerate, permethrin, cyfluthrin or other pyrethroid insecticide around September 1. The pyrethroid insecticides require three or four applications spaced every two weeks. The moths lay eggs at the base of peaches, plums, cherrylaurels, and ornamental cherries. From these eggs hatch tiny, white caterpillars that bore into the bark and tunnel in the cambium at the base of the tree. If many borers infest a tree, the cambium may be completely girdled beneath the bark and the tree will die. The borers pupate inside the infested tree during late spring and summer and then emerge as moths a few weeks later. Look for gummy plugs containing frass or partially projecting pupal skins. Pheromone traps are available (see http://www.gemplers.com or http://www.greatlakesipm.com on the Internet). It is important to spray to prevent further borers from invading the tree. The only control otherwise is to try to gouge the borer out from under the bark without injuring the tree excessively.
Armyworms are occurring in a few places, particularly in southeastern North Carolina. While the wet conditions have given them plenty of alternative vegetation to eat, we need to keep a watch for them. The 2 percent soapy water flush is a great tool to bring them to the turf surface and find them during the day.
Mole cricket damage is becoming quite obvious this time of year. Control is much more difficult and don't expect 80 percent or greater control in August and September. Green June beetle grub damage is also becoming much more obvious. I see a lot of locations with Scoliid wasps flying around in a Figure 8 pattern about a foot over the turf surface. These wasp (not a threat to humans) are actually parasites of green June beetle grubs. If you see a lot of these one inch to one inch and a half long dark blue wasps flying around it is an indication that a serious green June beetle grub infestation is present in the turfgrass. Remember that with green June beetle grubs an application of Sevin insecticide (carbaryl) will work very well for this species of grub, but you will end up with a lot of dead grubs on the surface.
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 August 25, 2003 by Stephen J. Toth, Jr.
