Balancing pest and pollinator management in cucurbit production systems

Production of cucurbit crops present growers with a number of challenges. Striped cucumber beetle Acalymma vittatum (F.) and squash bug Anasa tristis (DeGeer), are major direct pests and plant pathogen vectors. Management is critical due to the severe status of these pests and can include mechanical barriers, such as row covers, and chemical applications. However, considerations must also be made for pollinating insects, as adequate pollination affects the quantity and quality of fruit. Insecticides may negatively affect pollinators; a concern that has been enhanced in recent years in light of honey bee Colony Collapse Disorder, but when row covers are removed, pests are allowed access to fields along with the pollinators. If the pollination services of native bees could be harnessed for use under full-season row covers, both concerns could be balanced for growers. The pollination efficiency of Peponapis prunosa (Say), a specialist bee of cucurbits, was assessed in a field experiment where continuous row covers were employed over plots of acorn squash. Experimental treatments were either naturally or artificially infested with P. prunosa, and compared against negative and positive controls for pollination. Pests in the positive control were managed using standard practices utilized in certified organic production, while negative controls remained inaccessible to pests and pollinators alike. The marketable yields gleaned from plots inoculated with P. prunosa were statistically indistinguishable from those produced under standard practices, indicating that this system would provide adequate yields to growers without the time and monetary inputs of insecticide applications.