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ARS Home » Southeast Area » Charleston, South Carolina » Vegetable Research » Research » Publications at this Location » Publication #435250
Research Project: Basic and Applied Approaches for Pest Management in Vegetable Crops

Location: Vegetable Research

Title: Squash silverleaf disorder in Cucurbita spp.: a problem caused by the sweetpotato whitefly (Bemisia tabaci)

Author
item LUCKEW, ALEXANDER - University Of Georgia
item SARI, NEBAHAT - University Of Georgia
item SRINIVASAN, RAJAGOPALBABU - University Of Georgia
item Simmons, Alvin
item MCGREGOR, CECELIA - University Of Georgia

Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2026
Publication Date: 6/2/2026
Citation: Luckew, A.S., Sari, N., Srinivasan, R., Simmons, A.M., Mcgregor, C. 2026. Squash silverleaf disorder in Cucurbita spp.: a problem caused by the sweetpotato whitefly (Bemisia tabaci). Scientia Horticulturae. https://doi.org/10.1016/j.scienta.2026.114928.
DOI: https://doi.org/10.1016/j.scienta.2026.114928

Interpretive Summary: The sweetpotato whitefly is a tiny insect that causes significant damage to crops worldwide. One major issue is that it creates "squash silverleaf," which affects plants like squash and pumpkins. When immature whiteflies feed on these plants, their leaves change from a healthy green to a distinct silver color. Research shows that some squash cultivars possess a natural genetic ability to resist this silverleaf disorder. Interestingly, some plants naturally have silver leaves even without whiteflies, leading scientists to suggest that squash silverleaf might be a plant's defense mechanism mimicking this natural silvering. This knowledge is invaluable for farmers, helping them protect crops by managing whitefly populations and using resistant plants.

Technical Abstract: The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a devastating sap-sucking insect, is one of the most economically damaging agricultural crop pests worldwide. Squash silverleaf (SSL) is a disorder in plants in the genus Cucurbita that is caused by feeding by B. tabaci nymphs. Leaves of Cucurbita plants fed on by nymphs change from a healthy green to a silvery appearance. The severity of SSL disorder can be reduced by reducing the population of this pest by cultural, chemical, biological control, and host plant resistance. Genetic studies have shown that SSL disorder resistance is controlled by a single recessive gene, sl, along with modifying genes in both C. pepo and C. moschata. Leaf variegation with a silver appearance also occurs in Cucurbita in the absence of whiteflies. We revisit earlier studies that suggested that this silvering in Cucurbita is associated with insect non-preference and hypothesize that SSL disorder might be a defense response mimicking leaf variegation.