Characterization of early floral damage by cranberry tipworm (Dasineura oxycoccana Johnson) as a precursor to reduced fruit set in rabbiteye blueberry (Vaccinium ashei Reade)
Title:
Characterization of early floral damage by cranberry tipworm (Dasineura oxycoccana Johnson) as a precursor to reduced fruit set in rabbiteye blueberry (Vaccinium ashei Reade)
Author:
Dernisky, Andrea K. Evans, Rodger C. Liburd, Oscar E. Mackenzie, Kenna
Appeared in:
International journal of pest management
Paging:
Volume 51 (2005) nr. 2 pages 143-148
Year:
2005-04
Contents:
The cranberry tipworm, Dasineura oxycoccana, is an important insect pest of rabbiteye blueberries, Vaccinium ashei, in the southeastern United States, with annual losses from infestation and damage exceeding $20 million USD. Using rabbiteye flowers from a range of developmental stages, we examined floral tissues microscopically to determine specific areas targeted by D. oxycoccana, as well as the impact of oviposition and larval feeding. Our results indicate that oviposition by D. oxycoccana occurs early in the growing season, as larvae were found exclusively between bracts of expanding inflorescences and the base of developing flowers. When bracts were removed, tissue necrosis resulting from larval feeding was found encompassing the calyx tube region near the pedicel. Such damage potentially leads to premature floral bud abscission, or aesthetically compromised fruit when mature. In the field, evidence of D. oxycoccana infestation would be undetectable until overlying bracts had abscised, and damage had already progressed to an extreme state.