Submitted to: Entomological Society of America Regional Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 3/7/2006
Publication Date: 3/8/2006
Citation: Meagher Jr, R.L., Nagoshi, R.N., Stuhl, C.J. 2006. Larval preference of fall armyworm to corn and stargrass. Entomological Society of America Regional Meetings.
Technical Abstract: Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) is a noctuid pest of field crops, turf and pasture grasses, and cotton. The species is composed of two host strains: one feeds predominately on large grasses such as corn and sorghum (corn strain), while the other is found predominately in small grass and rice habitats (rice strain). Larval-choice studies were conducted using multiple bioassays to determine whether neonates of both strains have a preference for corn (Zea mays L. ‘Truckers Favorite’) or stargrass (Cynodon nlemfuensis Vanderyst var. nlemfuensis ‘Florona’). When given a choice of a section of each host-plant in a Petri dish bioassay, neonates of both strains chose corn sections significantly more than stargrass sections. When whole plant material was presented, corn strain larvae showed a preference for stargrass, while rice strain larvae were evenly distributed between the two plants. A plastic cage/wind-tunnel bioassay was developed to observe movement of larvae upwind through one host-plant to another. Corn strain larvae were evenly distributed between the two plants, regardless of plant position. Rice strain larvae showed a strong trend toward whichever host-plant it first encountered. These results suggest that there are genetic differences in larval behavior between the two host strains.