Impact of Herbivory and Plant Competition on the Growth of Hydrilla in Small Ponds

摘要

Insect herbivory and competition have been shown to negatively impact the ability of hydrilla (Hydrilla verticillata (L.f.) Royle) to grow and reproduce (Doyle et al. 2002). Previous research conducted at the Lewisville Aquatic Ecosystem Research Facility (LAERF), Lewisville, TX and other field sites has shown that sustained levels of herbivory by the leaf-mining flies (Hydrellia pakistanae Deonier and H. balciunasi Bock) can reduce hydrilla biomass by 30 percent, reduce reproduction via reduction in flowering and tuber/turion production, and impact the ability of hydrilla to photosynthesize (Grodowitz et al. 2003; Doyle et al. 2002; Doyle et al., in review). This technical note evaluates the impacts of insect herbivory and competition on dioecious hydrilla biomass, and tuber and turion production in small ponds.