Life table analysis of known noctuid pests of hemp, Cannabis sativa (L.)

Life table analysis of known noctuid pests of hemp, Cannabis sativa (L.)

Abstract

Recent faunistic studies have reported Chrysodeixis includens (Walker), Spodoptera exigua (Hübner), and Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) as defoliating pests of hemp, Cannabis sativa (L.). Increasing acreage of hemp across the United States provides a potential alternative host plant for these polyphagous pests. However, it is unknown if these species can complete their life cycle on this novel host. The objective of this study was to construct lifetables for C. includens, S. exigua, and S. frugiperda reared on hemp and two known hosts, cowpea and soybean. Neonate larvae were reared on foliar tissue throughout the duration of the experiment. Mortality, percent defoliation, and larval instar via head capsule slippage was monitored daily until pupation. Pupae were sexed and placed into mating containers. Life table statistics were calculated by observing daily egg deposition per adult female, total egg eclosion rates, and mortality. Preliminary data indicates the ability of C. includens, S. exigua, and S. frugiperda to complete an entire life cycle on hemp, suggesting that hemp is a viable alternative host plant for these polyphagous insects. This study provides important information to the growing body of literature on the pest complex of hemp in the United States.



Keywords: Noctuidae, Chrysodeixis includens, Spodoptera exigua, Spodoptera frugiperda