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Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/9/2008 Publication Date: 10/8/2008 Citation: Sisterson, M.S. 2008. Egg load dynamics of Homalodisca vitripennis. Environmental Entomology. 37(5):1200-1207(8). Interpretive Summary: The glassy-winged sharpshooter, Homalodisca vitripennis, poses a serious threat to grape production due to its ability to vector Xylella fastidiosa, the causal agent of Pierce’s disease. This insect is native to the Southeastern United States and has recently expanded its range into Texas, California, and French Polynesia. A detailed understanding of the reproductive biology of this insect will aid in developing novel control strategies. Thus, the timing of egg maturation and deposition relative to female age was investigated. Females did not produce mature eggs until at least one week after adult emergence. Egg deposition reduced the number of mature eggs carried by females, indicating that eggs were deposited faster than they were matured. Studies with females over their entire natural life span indicated no association of female age with the number of eggs deposited. Finally, the number of eggs matured per female, per day in field populations was estimated. The maximum number of eggs matured per female, per day was 5 and varied with time of year. Technical Abstract: Homalodisca vitripennis, the glassy-winged sharpshooter, poses a serious threat to grape production due to its ability to vector Xylella fastidiosa, the causal agent of Pierce’s disease. The glassy-winged sharpshooter is native to the Southeastern United States and over the last twenty years has expanded its range into Texas and California and more distantly into French Polynesia. A better understanding of the reproductive dynamics of H. vitripennis will aid in assessment of the invasiveness of this insect and may aid in refinement of control strategies. First, females of known age were dissected to determine egg maturation schedules. Females did not produce mature eggs until at least one week after adult emergence. Oviposition reduced the number of mature eggs carried by females, suggesting a continuous cycle of egg deposition followed by egg maturation where females may experience transient egg limitation. Second, males and females were monitored over their entire lifetimes to determine longevity and fecundity. Males and females were long lived with an average lifespan of 4 months. Females displayed one of three temporal patterns of oviposition: 1) laid no eggs, 2) began laying eggs <40 days after emergence or 3) began laying eggs >40 days after emergence. In general, oviposition was independent of female age. Finally, egg maturation rates of field collected females were determined. Egg maturation rates varied with time of year and maximum egg maturation rates coincided with periods when oviposition was expected to be high. The highest egg maturation rate observed was 5 eggs per female per day. |
