Research Entomologist

Professional Biographical Information:

Ph.D. in Entomology, Statistics Minor (1981), Pennsylvania State University

M.S. in Ecology (1981), Pennsylvania State University

M.S. in Forestry (1977), University of Idaho

B.S.F. with Highest Honors and Highest Distinction (1975), University of Maine

1985-present; Research Entomologist, Appalachian Fruit Research Station

1982-1985; Adjunct Assistant Professor, West Virginia University, Appalachian Fruit Research Station

1981-1982; Research Associate, Mississippi State University

Research Objective:

The objective of my research is to develop sustainable insect pest management methods for apple and peach, thus leading to a reduction in the use of chemical insecticides.  Modification of orchard management practices to make orchards more attractive to natural control organisms the environment is the primary thrust of my research program for increasing biological control.  The implementation of this type of conservation biological control will require input from all other disciplines involved in orchard management; the scientific staff at the Appalachian Fruit Research Station provides this diversity of disciplines needed to modify orchard management. An orchard relying on conservation biological control for pest management must be more attractive to beneficial species by offering them food and shelter. The orchard environment must also be made to be less harmful to the beneficial species, requiring fewer insecticides and those that are used to be more specific to the pest. I am using flowering companion plants in the orchard to provide shelter and food in the form of nectar and pollen to attract insect predators and parasitoids. We have shown that fruit from an orchard with companion plants and reduced insecticide use is of equal quality to fruit from conventionally managed (using insecticides) orchards.  Another method of providing food resources for biological control is through the addition of peach trees that produce large amounts of extrafloral nectar.  A grant from CSREES is facilitating a collaborative project with Dr. Clarissa Mathews, Institute for Environmental Studies, Shepherd University, to further investigate the interactions between peach extrafloral nectar and biological control.  A project in collaboration with Dr. Thomas Tworkoski has also shown that the application of compost mulch underneath orchard trees increases the biological control of several insect pests.  Current research is aimed at developing orchard planting designs that maximize biological control of arthropod pests while maintaining current levels of fruit production.

Accomplishments:

Woolly apple aphid. Research on the woolly apple aphid showed that the currently used threshold for control of this aphid is too high in the mid-Atlantic region and significant reduction in apple yield is being caused by low population densities feeding on apple tree roots.  Woolly apple aphid feeding reduces apple tree productivity by disrupting the water flow through the roots and by altering nitrogen allocation within the tree.  Work is continuing on the woolly apple aphid through cooperation with the Dr. Gennaro Fazio, Plant Genetic Resources Unit, ARS, Geneva, NY, to identify apple rootstock resistant to woolly apple aphid feeding.  

Spirea aphid.  Research on aphids on apple showed that the spirea aphid had replaced apple aphid as the dominant aphid on apple during the summer. Research on the ecological interactions between these species demonstrated how the spirea aphid was able to dominate apple orchards and led to revised recommendations for managing aphids. Biological control of spirea aphids was found to be adequate in apple orchards if insecticides that are toxic to aphid predators were not used. Biological control of aphids increased when the exotic Asian lady beetle (Harmonia axyridis) became the dominant predator of aphids on apple.

Stink bugs.  Damage caused by stink bug feeding on apples in late summer and fall is similar to the physiological disorder called cork spot.  The damage caused by stink bugs has been characterized and several apple cultivars have been evaluated for different levels of susceptibility to injury.  Research is continuing to develop methods to manage stink bugs and their damage through environmentally save methods.