Monday, December 11, 2006 - 9:11 AM

Switched after birth: Performance of viburnum leaf beetle (Pyrrhalta viburni [Paykull]) larvae after transfer to suboptimal hosts

Gaylord Desurmont, and Paul A. Weston, Cornell University, Department of Entomology, 150 Insectary, Ithaca, NY

Pyrrhalta viburni, an invasive chrysomelid native to Europe first detected in the USA in 1994, is becoming a major landscape pest in the northeast and poses a serious threat to a large portion of the U.S. Larvae and adults feed on shrubs in the genus Viburnum, and plants in both managed landscapes and natural areas are at risk. Plants belonging to susceptible species are often killed within a few years, but plants belonging to resistant species are rarely heavily defoliated. Preliminary trials have shown that young viburnum larvae are unable to survive and develop on such species. However, older larvae (3rd instar) have been observed in the field on resistant species. Trials were conducted to evaluate the ability of 3rd instar viburnum leaf beetle larvae to switch from a susceptible viburnum host (Viburnum dentatum) to a moderately susceptible (V. lentago) or resistant (V. sieboldii, V. carlesii) host. Larvae were able to reach pupal and adult stage on all given host plants, but exhibited higher survivorship on V. dentatum and V. carlesii. Weight gained per day and weight reached at pupation was highest for larvae feeding on V. dentatum. These results confirm that V. lentago, V. carlesii, and V. sieboldii are suboptimal hosts for viburnum leaf beetle, but can be used as alternate food to complete larval development under certain situations.

Species 1: coleoptera chrysomelidae pyrrhalta viburni (viburnum leaf beetle)

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