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Ornamentals and Turf |
The scentless plant bug, Niesthrea louisianica, is associated with rose-of-Sharon and hibiscus. It feeds on flower buds and seeds. Eggs are laid in masses, deposited on the undersides of leaves and it may have more than one generation per year in North Carolina. It is usually not damaging enough nor common enough to be considered a real economic pest as it usually does not cause noticeable injury. The most famous scentless plant bug is the boxelder bug which does no damage to boxelder, but is somewhat of a nuisance because it congregates on tree trunks and in homes in the fall. Other scentless plant bugs feed on various weeds and shrubs but usually do not cause noticeable injury. If Niesthrea louisianica becomes abundant enough to cause concern, a pesticide can be applied for control on flower buds, spent blooms, and undersides of leaves (if eggs are noticed). Avoid spraying open blooms to prevent killing bees. Hand removal is also effective if practical. Several agricultural chemicals are labeled for plant bug control on ornamental plants. Any of the following insecticides should give adequate control: pyrethrins, Sevin or most common lawn and garden insecticides. Landscapers may also use Tempo, Talstar One, or Mavrik.
The glassywinged sharpshooter, Homalodisca coagulata, is primarily a southeastern species of leafhopper. However, in the last few years, introductions into western states, especially California, has caused serious problems, primarily because of it's ability to transmit Pierce's disease which can be a major problem on grapes. Pierce's Disease also exists in dozens of other hosts. Fortunately, is rarely reported as a problem in North Carolina.
Heavy infestations of the sharpshooter produce copious amounts of leafhopper rain, making it a possible nuisance for those standing underneath an infested tree. We recently read of such a report in Pamlico County thanks to Ray Harris. Sharpshooters excrete honeydew droplets when they feed on plants. These droplets eventually wet people, cars, backyard play equipment, cars, sidewalks or whatever is beneath the tree. Sharpshooters filter out minerals and amino acids from the liquid sucked from plants. Each leafhopper must filter so much fluid to get adequate nutrition that it excretes a sizeable droplet of liquid about every few seconds. When dry, the watery excrement can leave trees and shrubs with a white-washed appearance. The glassywinged sharpshooter host list includes more than 100 species of plants. Favorite residential host plants for the sharpshooter include ash, camellia, crapemyrtle, magnolia, mulberry, oak, privet, apple, most stone fruits, blackberry, oleander, pine, sycamore, trumpet flower, wisteria, willow and yucca.
If control is necessary, any insecticide listed for leafhopper control may be used. Merit (imidacloprid) is labeled and a very effective systemic for this insect in ornamentals.
Rain, rain, rain. This seemed like a record season for darkwinged fungus gnat larvae and adults. Twolined spittlebugs did well and had a long run. The cool wet weather held off the armyworms so far this year which were almost eating our shoe laces at this time last year. Japanese beetles seemed below par or were, at least, more spread out over the season. Tent caterpillars seemed late and less abundant as did the fall webworms. Where were all the yellowjacket calls?
Don't forget the Ornamentals and Turf Insect Notes on the Internet at: http://insects.ncsu.edu. If you have any needs for insect notes that we don't have posted, send us a message via electronic mail.
A few pest problems remain in turf despite the summer coming to an end. There are still a few chinch bugs in St. Augustinegrass, but they really haven't had a chance to do much this year because of all the rain. Mole crickets are now large and causing serious damage in warm season turfgrass in sandy soils. Any brief periods without rain allow for the appearance of fire ant mounds and it seems like this Spring the fire ants were successful in establishing a lot of new colonies.
We have had a few reports of armyworms in turf, but this has been mostly in the southeastern portion of the state. White grubs are occurring everywhere and green June beetle grub damage is really peaking in mid September. Problems with pests like digging wasps (cicada killer wasps) seem to be declining.
When reseeding or resodding it is very important to give special attention to the likelihood of a fall armyworm infestation. While we haven't seen many this year so far, they really prefer new stands of grass and the moths will rapidly lay eggs on new sod or newly seeded stands. Watch such areas closely until we have had a hard, killing frost.
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 September 15, 2003 by Stephen J. Toth, Jr.
