1985 Fall Armyworm Symposium: Chemical Control: Oviposition and Subsequent Infestation of Corn by Fall Armyworm (Lepidoptera: Noctuidae)

Harrison, Floyd P.

Abstract


The events following oviposition by fall armyworm, Spodoptera frugiperda (J. E. Smith) on corn, Zea mays L., in the whorl stage are not adequately described. Infestation is obscure for some time after eggs hatch and larvae migrate from plant to plant until they mature. These characteristics confound field monitoring therefore the time from oviposition until foliar feeding is visible and the potential infestation from each egg mass needs to be quantified. Neonates feed in whorls and eventually become large enough for their feeding to be obvious. This damaged foliage then grows out of the whorl and is visible ca. 13 days after oviposition. The number of plants becoming infested by each egg mass is somewhat dependent on egg density. In the plots observed here, egg mass density ranged from 5 to 20 egg masses per 100 plants while the number of plants damaged as a result of larvae from each egg mass ranged from 5.16 to 3.06 plants per egg mass respectively.

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