Dissertation

Another parasitoid, Agathis stigmatera (Hymenoptera: Braconidae) was introduced fromPeru into Florida in the early 1930's and into Louisiana in the late 1940's and early 1950's. In theCaribbean islands and much of South America, it had been known to be parasitizing Diatraeaspp. since the 1920‘s (Smith et al., 1993). Other parasitoid species released in Louisiana afterthe original introductions included tachinids, braconids, and scelionids. Some of the abovespecies have become established in Louisiana and Florida, but none have provided consistentstem borer population suppression (White and Reagan, 1999).1.1.4. The Fall ArmywormThe fall armyworm, Spodoptera frugiperda, is a polyphagous insect which is animportant pest on several crops (Luginbill, 1928). It was originally reported as a pest of rice inGeorgia in 1881 (Riley, 1881). Although its host range is wide, cereals and grasses are the mostpreferred among it host plants (Crumb, 1927). When infesting rice, S. frugiperda rapidlydefoliates seedlings. Larvae typically feed and develop and become fully grown in two to threeweeks. Most larvae that develop on flooded rice never pupate, as larvae normally pupate in thesoil, and because of this, are considered a sporadic pest of rice in the southern United States(Bowling, 1978; Smith et al., 1986). In other countries, however, S. frugiperda has beenreported to cause severe damage to rice at the seedling stage (Chandler et al., 1977; Machado,1978; Navas, 1976). Despite its ability to rapidly defoliate stands of rice, Lye and Smith (1988)found that maximum larval weight of S. frugiperda was higher when fed three-leaf stage O.sativa foliage, but weights were lowest when larvae were fed material from older plants.Similarly, Hardy et al. (1986) reported that both neonate and fourth instar S. frugiperda larvaefeed more on new growth than on older growth of tall fescue grass.10