Monday, December 10, 2007 - 10:53 AM

Influence of four different lawn management programs on the abundance of plant-feeding and beneficial arthropods

Victoria Caceres, and Douglas S. Richmond, Purdue University, Department of Entomology, 901 W. State Street, West Lafayette, IN

This study examined the influence of four different lawn management programs on the abundance of plant feeding and beneficial arthropods over the course of two field seasons. Management programs included a Consumer /garden center program, an IPM program, an Organic program and a No input program that served as an experimental control. Applications of fertilizers and synthetic pesticides in the IPM and Consumer programs had measurable although inconsistent effects on the abundance of herbivores, predators and decomposers over the two years of the study. Total cumulative abundance of plant feeding arthropods was lower in the IPM program compared to the rest of the programs and this trend was also observed on certain individual sampling dates. Although no insecticides were used in the IPM program during the 2006 season, total cumulative predator abundance was significantly lower than all other programs. This effect was mainly manifest in lower numbers of Coccinelids, Orius spp., Geocoris spp. and Carabids. Decomposer abundance, mainly dung beetles and collembola, was reduced by synthetic pesticide applications made in the IPM program during 2005 and in the Consumer program during 2006. Overall, the IPM program was the most effective at lowering herbivore abundance followed by the Consumer program. However these two programs had negative impacts on beneficial arthropods such as predators and decomposers. Although decomposers and predators were unaffected in the Organic and No input programs, herbivore abundance was higher in both programs contributing to slower growth and reduced vigor of the turfgrass stand.