Lesser Cornstalk BorerWayne N. Dixon - Forest Entomologist, Florida Divisions of Foresty and Plant Industry, Gainesville, FL. Cordell C.E., Anderson R.L., Hoffard W.H., Landis T.D., Smith R.S. Jr., Toko H.V., 1989. Forest Nursery Pests. USDA Forest Service, Agriculture Handbook No. 680, 184 pp. Hosts The lesser cornstalk borer (Elasmopalpus lignosellus) affects seedlings of Arizona cypress, bald-cypress, black locust, dogwood, tupelo-gum, loblolly pine, redcedar, sand pine, slash pine, and sycamore. Agricultural host plants (over 60 species) include beans, corn, millet, peas, sorghums, and soybeans. Distribution Complete girdling results in death of the seedling. Partially girdled seedlings usually recover. Mortality in Arizona cypress may be increased by infection of wounded seedlings by the fungus Dothiorella sp. Diagnosis
After emerging from the soil in late spring, moths mate, and female moths deposit eggs singly in the soil at the bases of host plants or on stems and lower leaves. Each female lays approximately 125 eggs. Eggs hatch within 1 week, and larvae mine lowermost branches or begin semisubterranean feeding on stems and roots. Larvae feed from 2 to 3 weeks. Pupation occurs in silk tunnels or soil litter and takes 2 to 3 weeks. Then new adults emerge, mate, and live about 10 days. Larvae or pupae overwinter in the soil or soil litter. Control Cultural - Certain cover crops, sandy soils, and droughty weather encourage infestations in forest nurseries. Practice general sanitation measures, late fall plowing, and nonsusceptible cover crop rotation to reduce the incidence of lesser cornstalk borer. Chemical - Apply a preventive insecticide. Granular insecticides like carbofuran, chlorpyrifos, diazinon, fensulfothion, or fonofos can be applied to the soil when the cover crop is planted. The insecticide used will depend on the cover crop. A remedial, supplementary treatment may also be required. Apply an insecticide such as carbaryl or diazinon as a soil drench at the first sign of seedling damage. Additional applications may be needed because the silk tunnels of the larvae make it difficult to ensure that the insect has been adequately exposed to the insecticide. Selected References Davis, T.C.; Goggans. J.F.; Meier, R.J. 1974. Pest control problems encountered in seedling production of Arizona cypress in Alabama. Tree Planters' Notes. 25(2): 7-9. Leuck. D.B. 1966. Biology of the lesser cornstalk borer in south Georgia. Journal of Economic Entomology. 59: 797-801. |