Influence of Orchard Weed Management Practices on Soil Dwelling Stages of Plum Curculio, Conotrachelus Nenuphar (coleoptera: Curculionidae)

Plum curculio, Conotrachelus nenuphar Herbst (Coleoptera: Curculionidae), is a key pest of peaches in the southeastern United States. Part of its life cycle, specifically, the pre-pupal, pupal and pre-adult stages are spent in the soil. Experiments were conducted in 2 peach orchards to evaluate the effects of some common orchard weed management practices on the development of the soil dwelling life stages of plum curculio. Four common orchard weed management practices (treatments) were evaluated in plots (3 m × 3 m) located under peach tree canopies: centipede grass, Eremochloa ophiuroides (Munro) understory (soil covered with centipede grass); weed free understory (bare soil, weeds removed with herbicide sprays); weedy (natural weeds) understory; and pine bark understory (soil covered with pine bark). Fewer numbers of adult plum curculio emerged from the centipede grass understory plots compared with weed free, weedy or pine bark treated understories. Similar results were obtained in the greenhouse: fewer adults emerged from centipede grass than bare soil in spring 2009. Possible reasons for the lower emergence of plum curculio in centipede grass plots are proposed.