Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/8/1997
Publication Date: N/A
Interpretive Summary: Infestations of beet armyworm and other pests occurring on south Texas cotton were monitored during the 1996 production season. Although beet armyworm moths were detected continuously at each of two locations during a 4-month study period, immature forms on cotton remained at extremely low levels and caused no appreciable damage to cotton plants. Survival studies sindicated an extremely high incidence of mortality (greater than 99%) amon immature beet armyworms, much of which was caused by a complex of native predators. Natural enemies were generally abundant at both locations and appear to have been primarily responsible for maintaining beet armyworm infestations at the extremely low levels that were evident throughout the 1996 cotton season. Results of these studies demonstrated the significance of native natural enemies in the natural control of beet armyworm, and emphasized the need to conserve these important insects in areawide pest management and suppression efforts.
Technical Abstract: Population trends of beet armyworm, Spodoptera exigua (Hubner), and its natural enemy associates on south Texas cotton were monitored during the 1996 production season. Pheromone traps detected a continual presence of beet armyworm moths at each of two study locations throughout a 4-month study period. However, infestations of the pest in a series of cotton plantings remained at innocuous levels throughout the season and caused no appreciable damage to plants. The latter trend was attributed to an extremely high incidence of mortality among immature stages (>99%), much of which was caused by members of an indigenous natural enemy species complex. The principal natural enemy groups included a complex of spiders, predaceous bugs (e.g., Orius and Geocoris spp.), beetles (e.g., Hippodamia and Scymnus spp.), and green lacewings (e.g., Chrysoperla spp.). The significance of indigenous natural enemies in the beet armyworm life system mof southern Texas is discussed.