Evaluating the impacts of grass and legume living mulches on arthropod pests and beneficials, yield, and fruit quality in cantaloupe.

Abstract

Increasing plant diversity in agroecosystems is often proposed as a way to reduce arthropod pest pressure and support natural enemy populations to reduce reliance on traditional chemical controls. Over 2 field seasons, we examined the effects of interplanting cantaloupe (Cucumis melo L. var. cantalupensis) with alsike clover (Trifolium hybridum L.) and Virginia wildrye (Elymus virginicus L.) on arthropod populations, cantaloupe yield, and fruit quality. Arthropod sampling through visual counts, sticky cards, and pitfall traps focused on herbivores and natural enemies across feeding guilds, with more specialized pests in the cucurbit system being identified to lower taxonomic levels. Living mulches might have delayed initial crop colonization by striped cucumber beetles (Acalymma vittatum F.) but had limited impact on beetle counts, which remained similarly low throughout the study across treatments. Aphid populations were lowest in wildrye interplanted plots, suggesting species-specific impacts on pest suppression. Beneficial arthropods, such as spiders, piercing predators, and parasitoids, were often more abundant in clover than in wildrye or monoculture plots, especially early in the season. However, cantaloupe yield was highest in monoculture plots, where fruit showed increased weight, size, and favorable color metrics compared to those from living mulch plots. These results indicate that while living mulches can support beneficial arthropods and possibly reduce early pest pressure, they may also introduce trade-offs in yield and quality. Future studies should explore adjustments to living mulch management in cantaloupe, such as reduced density or narrower planting strips, to optimize pest suppression benefits while limiting competition with the cash crop.