Monday, December 10, 2007 - 10:41 AM

Management of a whitefly-borne virus and aphids in zucchini squash using living and synthetic mulches with imidacloprid

Teresia Nyoike, and Oscar E. Liburd, University of Florida, Entomology and Nematology, Bldg 970 Natural Area Drive, Gainesville, FL

Living mulch, buckwheat Fagopyrum esculentum Moench, and UV reflective mulch in combination with (Imidacloprid [Admire 2F]) significantly reduced Cucurbit Leaf Crumple Virus, a whitefly-borne virus and its vector (B biotype of Bemisia tabaci Gennadius), and aphid populations in zucchini squash. Treatments evaluated included living mulch with and without Admire 2F and UV reflective with and without Admire 2F. The mulches were compared with standard white mulch in fall 2005 and 2006 in Florida. In 2005, there were no incidences of insect-transmitted viruses where as in 2006 Cucurbit leaf crumple virus (CuLCrV), a virus new to Florida was found. Plants growing within white mulch had the highest incidences of CuLCrV while the lowest incidences were observed in mulches with Admire 2F. Similarly, mulches with Admire 2F were more effective in reducing whiteflies than mulches without the insecticide. In 2005, treatments with Admire 2F had significantly fewer aphids per leaf compared with all other treatments including control. Alate aphid counts from the pan traps indicated that there were no significant differences between treatments with and without Admire 2F. Yield results were consistent between the two years of the study. Reflective mulch with Admire 2F had significantly higher yields than the living mulch treatments and the control. Living mulch treatments had consistently lower yields than all the other treatments. Addition of Admire 2F enhanced yield only in the living mulch treatment in 2005. Overall, reflective and living mulch with Admire 2F reduced whitefly densities and hence the virus incidence.

Species 1: Hemiptera Aleyrodidae Bemisia tabaci (silverleaf whitefly, B biotype)
Species 2: Hemiptera Aphididae Aphis gosspyii (melon aphid)