The larva of the moth Helicoverpa zea (formerly in the genus Heliothis) is a major agricultural pest, found in temperate and tropical regions of the world, mainly in North America. (Helicoverpa armigera, a close relative of H. zea, is a major pest in Asia, Africa and Australia). Helicoverpa zea larvae feed most commonly on corn, but do eat over 100 different plant species as well. Accordingly, the species has been given many different common names. When the larva consumes cotton, it is known as the cotton bollworm. When it consumes corn, it is known as the corn earworm. When it consumes tomatoes, it is known as the tomato fruitworm. Typically the larvae feed on blossoms, buds and fruits, which are often the harvestable portion of valuable crops, and annoyingly, they often feed for just a short time on one fruit before moving on to damage another. Helicoverpa zea overwinters in the pupal stage. Within North America H. zea does not successfully overwinter in states with severe winters (for example, on the east coast, further north than New Jersey) but more northern states will harbor immigrant populations depending on winter severity. Cold states will have only one generation per year, while the warmest areas, for example southern Florida, can have up to seven. Helicoverpa zea is most destructive to crops in states where it can overwinter. The impact of this pest has been and continues to be significant, especially because of the wide range of crops attacked, and the natural abundance of the species in the wild. Several forms of management are used, including planting resistant hybrid crops and spraying chemical insecticides and biological insecticides, such as Bacillus thuringiensiskurstaki (Bt). Natural predators such as the big-eyed bug (Geocoris), the minute pirate bug (Orius), and the spotted lady beetle (Coleornegillamaculata), and parasitic wasps Trichogramma also help keep populations in check.
(Capinera, 2000; Cook and Weinzierl 2004; Hagerman 2011; Wikipedia 2011)
(Capinera, 2000; Cook and Weinzierl 2004; Hagerman 2011; Wikipedia 2011)
- Archer, T.L. and E.D. Bynum, Jr. 1994. Corn earworm (Lepidoptera: Noctuidae) biology on food corn on the High Plains. Environmental Entomology 23:343-348
- Capinera, J.L. 2000, revised August 2007. Featured creatures: corn earworm. University of Florida Institute of Food and Agricultural Sciences. Publication Number: EENY-145. Retrieved September 13, 2011 from http://entnemdept.ufl.edu/creatures/veg/corn_earworm.htm
- Cooke, K.A. and R. Weinzierl, 2004. IPM: Field Crops: Corn Earworm (Heliothis Zea). Retrieved Sept 14, 2011 from http://ipm.illinois.edu/fieldcrops/insects/corn_earworm/index.html
- Ditman, L.P. and E.N. Cory, 1931. The corn earworm biology and control. Maryland Agricultural Experiment Station Bulletin. 328. 482 pp.
- Hagerman, P., 2011. Corn Earworm Factsheet. Ontario ministry of agriculture, food, and rural affairs. Retrieved Sept 14, 2011 from http://www.omafra.gov.on.ca/english/crops/facts/95-065.htm
- Hardwick, D.F. 1965b. The corn earworm complex. Entomological of Society Canada. 40. 246 pp.
- Martin, P.B., P.D. Lingren, and G.L. Greene. 1976a. Relative abundance and host preferences of cabbage looper, soybean looper, tobacco budworm, and corn earworm on crops grown in northern Florida. Environmental Entomology 5:878-882.
- Martin, P.B., P.D. Lingren, G.L. Greene, and R.L. Ridgway. 1976b. Parasitization of two species of Plusiinae and Heliothis spp. after releases of Trichogramma pretiosum in seven crops. Environmental Entomology 5:991-995.
- Neunzig, H.H. 1963. Wild host plants of the corn earworm and the tobacco budworm in eastern North Carolina. Journal of Economic Entomology 56:135-139.
- Neunzig, H.H. 1964. The eggs and early-instar larvae of Heliothis zea and Heliothis virescens (Lepidoptera: Noctuidae). Annals of the Entomological Society of America 57:98-102.
- Neunzig, H.H. 1969. The biology of the tobacco budworm and the corn earworm in North Carolina with particular reference to tobacco as a host. North Carolina Agricultural Experiment Station Technical Bulletin 196. 76 pp.
- Oatman, E.R. and G.R. Platner. 1971. Biological control of the tomato fruitworm, cabbage looper, and hornworms on processing tomatoes in southern California, using mass releases of Trichogramma pretiosum. Journal of Economic Entomology 64:501-506.
- Purcell, M., M.W. Johnson, L.M. Lebeck, and A.H. Hara. 1992. Biological control of Helicoverpa zea (Lepidoptera: Noctuidae) with Steinernema carpocapsae (Rhabditida: Steinernematidae) in corn used as a trap crop. Environmental Entomology 21:1441-1447.
- Quaintance, A.L. and C.T. Brues. 1905. The cotton bollworm. U S.Department of Agriculture Bureau of Entomology Bulletin 50. 155 pp.
- Wikipedia, The Free Encyclopedia April 17, 2011. "Helicoverpa zea". Retrieved Sept 14, 2011 from http://en.wikipedia.org/w/index.php?title=Helicoverpa_zea&oldid=432769340
