Variation Among Muskmelon Cultivars in Attractiveness to Striped Cucumber Beetle and Severity of Bacterial Wilt

Muskmelon (Cucumis melo L.), is one of the most important vegetable crops in the United States. Bacterial wilt of cucurbits, which is caused by Erwinia tracheiphila and vectored by striped cucumber beetle (Acalymma vittatum F.), is one of the most serious diseases of muskmelon that influences quality and yield. Many cultivars of muskmelon are grown around the United States, especially in the Midwest. Muskmelon cultivars differ in attractiveness to the striped cucumber beetle (SCB) and susceptibility to bacterial wilt (BW), and no cultivar resistant to BW has been introduced. We conducted field studies in 2015 with 10 to 11 cultivars at three locations in Indiana to identify those most and least attractive to SCB and susceptible to BW. Replicated plots of each cultivar were grown and natural populations of SCB allowed to feed. At one location, additional plots of each cultivar were populated with 5 SCB per plant, and row covers applied to keep the SCB near the plants for 3 weeks. Results differed among locations. Without row covers, cultivars Diplomat and RML 9818 attracted higher numbers of SCBs than most other cultivars at one location each. ‘Dream Dew’ (at all locations) and ‘RML 9818’ (at two locations) had significantly higher percentages of BW than the least susceptible cultivars. Without row covers, ‘Superstar’, ‘Aphrodite’ and ‘Wrangler’ produced significantly greater yield than the lowest yielding varieties at all locations. With row covers, early season beetle populations did not differ among cultivars and BW was greatest in ‘Dream Dew’ and least in ‘Superstar’ with other cultivars intermediate. With row covers, ‘Athena’ and ‘Superstar’ produced greater yield than many other cultivars. Experiments will be continued in summer 2016.