Effect of Two Parasites, Anisopteromalus calandrae and Choetospila elegans upon Populations of the Maize Weevil Under Laboratory and Natural Conditions12

Anisopteromatus calandrae (Howard) and Choetospila eleegans Westwood were found to be natural parasites of the immature stages of the maize weevil, Sitophilus zeamaize Motschulsky, in weevil-infested corn at several locations in Louisiana. A. calandrae was found more frequently than C. elegans. In a period of 4 months, under laboratory conditions, the numbers of adult weevils produced when A. calandrae ami C. elegane were present were ca. 5 and 11 %, respectively, of the number produced in the absence of parasites. Under laboratory and outdoor environmental conditions, the mean weevil progeny in the A. calandrae treatment was less than ½ that produced in the control under both environmental conditions. C. elegans was less effective under both conditions but appeared to reduce weevil populations by ½ and ¼ under outdoor and under laboratory conditions, respectively. Reproduction by C. elegans was found to he arrhenotokous.