Effects of living and synthetic mulch on the population dynamics of whiteflies and aphids, their associated natural enemies, and insect-transmitted plant diseases in zucchini

Abstract

Living and synthetic mulches were evaluated for control of the silverleaf whitefly, Bemisia argentifolii Bellows and Perring, and aphids in zucchini plantings. Two living mulches, buckwheat, Fagopyrum esculentum Moench, and white clover, Trifolium repens L., and two synthetic mulches (reflective and white) were evaluated during the fall of 2002 and 2003. Results from pan-traps, yellow sticky traps, and foliar counts showed that reflective and buckwheat mulches consistently had fewer numbers of adult whiteflies and aphids compared with the standard white mulch treatments. In 2003, a significant increase in the abundance of natural enemies was recorded in all treatments. Living mulch treatments had higher natural enemy populations than synthetic mulch and bare-ground treatments. However, there were no differences in the species diversity of natural enemies found between treatments. The effectiveness of mulches for controlling immature whitefly numbers and the incidence of squash silverleaf disorder were inconsistent between years. Additional data taken at the end of the 2003 season revealed that two viral strains (PRSV-W and WMV-2) were present in the field. However, visual symptoms associated with these viral diseases did not occur until the end of the season. © 2005 Entomological Society of America.