Life table analyses and feeding behaviors of cannabis aphid, cotton aphid, and green peach aphid (Hemiptera: Aphididae) on industrial hemp.

Abstract

Industrial hemp, Cannabis sativa L., is an herbaceous annual plant that has recently re-entered crop production both in the field and in greenhouses within the United States. Like many agronomic crops, hemp production faces several insect pest challenges. Aphids pose a unique threat to hemp, being found in both indoor and outdoor production. Aphids affect hemp by reducing plant growth, bud production, concentrations of cannabinoids, and removing photosynthate. Additionally, aphids are vectors of plant viruses, and several species are known to transmit viruses to hemp. Limited research exists regarding the host suitability of hemp for common aphid pests in Louisiana. Thus, experiments were conducted to determine the life table statistics and feeding behaviors of Myzus persicae, Aphis gossypii, and Phorodon cannabis to determine the potential pest population dynamics of these pests on hemp. Hemp cv. Maverick was not a good host for either A. gossypii or M. persicae, resulting in negative intrinsic rates of increase and no sustained colonization. Although individuals of M. persicae and P. cannabis initiated probes at comparable rates, M. persicae probe durations were significantly shorter and probes were more frequent, indicating an absence of positive responses to probing hemp. A significant difference was observed in the percentage of individuals of A. gossypii initiating probes, and probe duration was significantly shorter than P. cannabis and significantly longer than M. persicae. Both A. gossypii and M. persicae spent significantly less time probing in phloem when compared with P. cannabis. These electrical penetration graph results indicate that A. gossypii and M. persicae do not find C. sativa cv. Maverick a suitable host; however, both species of aphids may still pose a threat to C. sativa production as virus vectors.