Squash bug host preference is associated with cucurbit yellow vine disease incidence across cucurbit species

Cucurbit yellow vine disease (CYVD), caused by Serratia ureilytica and transmitted by the squash bug [Anasa tristis (De Geer), 1773], is a recurring threat to cucurbit production in the United States, yet information on vector host preference and its relationship to disease incidence remains limited. Understanding squash bug-host associations is critical for improving integrated pest management (IPM) strategies for CYVD. We evaluated squash bug abundance and CYVD incidence across six cucurbit species (Cucurbita maxima, C. pepo, C. moschata, Cucumis melo, C. sativus, and Citrullus lanatus) in field trials conducted in Geneva, NY, USA, from 2023 to 2025. Adult, nymph, and egg abundance were recorded weekly, and CYVD incidence and plant mortality were assessed throughout the season. Squash bug populations differed significantly among cucurbit species and years, with consistently higher abundance observed on Cucurbita spp. compared with Cucumis spp. and Citrullus sp. In addition, CYVD incidence and plant mortality were highest in Cucurbita spp. Interannual variation in squash bug abundance and disease incidence was associated with temperature and growing degree-day accumulation, with the highest disease pressure observed in 2024 following a mild winter. Linear regression analyses indicated that squash bug abundance was correlated with CYVD incidence across host species. These results demonstrate that, although other factors might play a role in CYVD incidence, host preference by squash bugs appears to strongly influence CYVD incidence in cucurbits. Insights from this study provide a foundation for improving predictive models and IPM strategies for CYVD and targeted scouting and potential trap cropping for squash bugs.