Questions of diversity in tree fruit orchards utilizing grazed hogs

Agricultural monocultures severely limit biodiversity and may constrain ecological services within many agroecosystems. Adding hog rotational grazing to tree fruit agricultural systems not only diversifies farm enterprises but also affects ecological diversity. As hogs graze in the orchard, they consume dropped fruit and root in the soil. Larvae of several economically important insect pest species can be found in dropped fruit and in the soil. Grazing can provide direct biological control services. In particular, rotational grazing of hogs has been found to provide partial management of plum curculio Conotrachelus nenuphar (Herbst), codling moth Cydia pomonella, and Oriental fruit moth, Grapholita molesta (Busck). Hogs have also been found to significantly impact ground cover, thus providing another service through managing weeds and possibly reducing the incidence of fungal disease apple scab (Venturia inaequalis). However, the impacts of grazing hogs are not limited to pests. Beneficial organisms, such as predatory beetles and earthworms, are impacted as well.