Approaches for assessing the impact of Zea mays (Poaceae) on the behavior of Spodoptera frugiperda (Lepidoptera: Noctuidae) and its parasitoid Cotesia marginiventris (Hymenoptera: Braconidae)

Authors: Block, Anna; Mendoza, Jorrel; Rowley, Amy; Stuhl, Charles; Meagher, Robert - Rob

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/26/2020
Publication Date: 1/19/2021
Citation: Block, A.K.; Mendoza, J.S.; Rowley, A.L.; Stuhl, C.J.; Meagher Jr, R.L. 2021. Approaches for assessing the Impact of Zea mays on the behavior of Spodoptera frugiperda and its parasitoid Cotesia marginiventris. Florida Entomologist. 103:505-513. https://doi.org/10.1653/024.103.00414
DOI: https://doi.org/10.1653/024.103.00414

Interpretive Summary: The insect pest fall armyworm is a global problem for agriculture particularly impacting the production of staple corn crops. Multiple overlapping approaches are required to combat this pest. ARS scientists from Gainesville FL have developed a technique to assess the attractiveness of individual corn varieties to this pest with the goal of discovering or breeding less attractive varieties that are more resistant. Furthermore, the scientists have developed a technique to assess the ability of a parasitoid wasp to act as an effective biocontrol agent on different corn varieties. These techniques can aid in selection of corn lines that both hide from fall armyworm infestations and are more amenable to the use of biocontrol, thus helping to control armyworm without relying solely on pesticide use.

Technical Abstract: Plant derived volatiles are widely used cues that guide the behavior of plant associated insects, influencing both the ability of insects to locate host plants as well as tritrophic interactions with predators or parasitoids. An understanding of how volatiles impact a specific ecological system can therefore aid the development of plants that are less attractive to pests or more amenable to biocontrol. As each plant-insect interaction is different it is important to develop bioassays to compare plants with different volatile profiles and assess their comparative attractiveness to specific insects. To this end we developed a laboratory-based pair-wise choice assay to determine the oviposition preference of Spodoptera frugiperda (fall armyworm), a global crop pest, to Zea mays (maize) plants with different volatile profiles. An alternative greenhouse-based assay was also developed to assess the effect of different Z. mays plants on the oviposition behavior of Cotesia marginiventris, a parasitoid wasp that can be used as a biocontrol agent for S. frugiperda. These bioassays are easily adaptable for use on a range of plant-insect interactions.