ARS | Publication request: CAN THE ADDITION OF A LIVING MULCH TO SOYBEAN IMPROVE BIOLOGICAL CONTROL OF SOYBEAN APHID?

Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: December 18, 2005
Publication Date: December 18, 2005
Citation: Schmidt, N.P., O'Neal, M., Singer, J.W., Kohler, K.A. 2005. Can the addition of a living mulch to soybean improve biological control of soybean aphid? [abstract]. Entomological Society of America Annual Meeting. Paper No. 0337.

Technical Abstract: We are investigating the impact of living mulches on beneficial and pest insects as part of a long-term study on the addition of living mulches to annual crop production. In 2004, we observed a greater number of soil and foliar-based predators on soybean [Glycine max (L.) Merr.] grown with a living mulch comprised of either alfalfa (Medicago sativa L.) or kura clover (Trifolium ambiguum M.B.). Abundance of aphidophagous predators was greatest in soybean planted with a living mulch in June, when soybean aphids (Aphis glycines Matsumura, Hemiptera: Aphididae) are immigrating from their overwintering host. In 2005, we are testing the hypothesis that natural enemy abundance will increase and soybean aphid establishment and population growth will decline when soybean is grown in an alfalfa living mulch. Replicated plots (4 replications, 30 m wide and 27 m long) of soybean were planted with and without a fall-sown alfalfa. We are measuring natural enemy abundance with yellow sticky cards, pitfall traps and sweep-nets on a regular basis from May to September. To measure the impact of natural enemies on soybean aphid, we are employing natural enemy exclusion cages in soybean grown with and without alfalfa. In June, we will artificially infest caged and uncaged plants with soybean aphid. Natural enemy sampling in May 2005 revealed a nearly 2-fold increase in soybean grown with alfalfa. By comparing the rate of soybean aphid predation in soybean grown with and without alfalfa we will determine if this enhancement of natural enemies leads to pest suppression.