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Ornamentals and Turf |
Species of periodical cicadas (Brood IX) are emerging in northwestern regions of North Carolina, and it should be a fairly spectacular emergence in some locations. This seems to be one or two weeks earlier than expected. Periodical cicadas are sometimes incorrectly called locusts (true locusts are Old World grasshoppers). Periodical cicadas are all 1 to 1.5 inches long including the wings. The eyes, legs and margins of the wings are orange. Periodical cicadas sing and fly in spring whereas other species of cicadas usually sing and fly during the summer. After spending years in the soil, cicada nymphs dig their way to the surface (and sometimes even construct mud chimneys up to 3 inches tall). Usually, in late May or early June, the nymphs crawl to the trunk of a tree or some other object and cling there. Soon the insect molts into the winged adult stage, leaving behind the cast skin. Adult males begin to sing with a shrill buzzing noise to attract females. After mating, females use their saw-like ovipositors to open slits in the bark of hardwood twigs and insert eggs in two rows. Damage by cicadas is caused by the tiny slits made during egg laying. Heavily-damaged twigs may die back. This is normally not a significant problem with large trees. After 6 or 7 weeks, the eggs hatch and tiny, ant-like first stage nymphs drop to the soil to burrow in for the next two or more years (periodical cicadas develop for 13 to 17 years). While in the soil, the nymphs feed on the roots of many kinds of trees but do not cause noticeable damage. Farming and urbanization of suitable habitats has reduced the populations of many cicadas, and it is thought that some broods of periodical cicadas may be extinct.
In woodlands, around homes and in most landscapes it is neither practical nor desirable to try to eliminate cicadas. However, landscapers, nurserymen and apple growers may want to protect valuable woody shrubs and small trees. Covering with a lightweight fabric can protect ornamental trees and shrubs that are small enough. For more information on these and other species of cicadas, see Ornamentals and Turf Insect Information Note No. 17, or visit the University of Michigan periodical cicada web site.
Dead flies are being reported poised atop shrubs and asparagus ferns in gardens and landscapes. Many of these are seedcorn maggot flies that were infected with fungus and landed upon an elevated perch on which to die. The fungus sporulates from this vantage point. (Good for the fungus, bad for the fly.) Seedcorn maggot flies are grayish-brown and about one-fifth inch long. The legs are black and there are bristles scattered on the body. Flies that are infested with Entomophthora fungi become bound to twigs, leaves, wires and other objects by the mouthparts. Infected flies are swollen and have pinkish-colored bands on the abdomen. Sometimes gray Entomophthora spores are visible on the fly and on the substrate nearby.
Seedcorn maggots feed primarily on decaying organic matter, but sometimes infest the seeds and seedlings of vegetables such as corn and beans. The dead, fungus-infected flies are sometimes abundant on the dead twigs of dogwood and crape myrtle in the spring. Most of the damage is caused by the maggot stages that sometimes kill germinating vegetable seeds; this results in poor stands and the need to replant. Injury is usually most severe during wet, cold seasons and on land rich in organic matter. Although the fungus-infected flies appear to be sucking the life out of a plant, these adult flies are harmless. For more information, see Ornamental and Turf Insect Note Number 20 and North Carolina Cooperative Extension Service Bulletin AG-271.
Tiny red mites by the billions may be seen crawling about lawns, walkways, houses, and the pink flamingo in your yard. Adult mites are rusty-brown to dark red in color and smaller than the head of a pin. The front legs are longer than the body. Immature stages are bright red. This mite can reproduce without mating and large populations can develop quickly. Clover mites breed and feed in grasses, clovers and certain ground-covers surrounding homes and buildings. There have been reports in the literature of Bryobia damage to impatiens and lobellia. The worst infestations are often reported in new lawns and lawns that have been heavily fertilized. Differing weather patterns seem to elicit differing behaviors or different Bryobia species. Clover mites are a cool-season mite. They seem to be most numerous in the spring, but may also be abundant during the Fall or on warm days in the winter.
They are no threat to people or pets and are more of an annoyance if they move into houses around doors and window sills. They will not survive indoors. For more information, see Ornamental and Turf Note Number 124.
May and June beetles (not including green June beetle) are already beginning to appear. These scarab beetles are among the group called white grubs or Polyphaga. Grubs spend two or three years in the soil and emerge as black or brownish beetles in the spring. They are attracted to lights and will occur on porches or banging against your windows at night. This is such a broad group that there are no specific control measures to offer. Sometimes the grubs are found in high densities in turf or nursery stock such that insecticides are required, but there is no cure for the beetles banging against the window at night except to go to bed early.
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 19, 2003 by Stephen J. Toth, Jr.
