Click here to listen to Enchenopa binotata.

An important goal of this National Science Foundation sponsored research is to understand the role of mating signals in promoting genetic divergence, and ultimately speciation in sympatric populations of phytophagous insects. This is a collaborative project with Thomas K Wood (deceased), University of Delaware and Reginald B. Cocroft, University of Missouri. The model system that we are studying is Enchenopa binotata which is actually a complex of nine as yet unnamed species of treehoppers that are specialists on various trees and shrubs in eastern North America (see Wood et al. 1999). This summer attraction calls emitted by males collected from across the eastern United States were recorded in the Cocroft lab and here at IUS. Ongoing analyses are aimed at determining variation within and among populations and species. In addition to research on existing species, we are studying populations of Enchenopa that have been experimentally shifted to novel hosts in an effort to understand the interplay between natural and sexual selection in promoting genetic divergence in sympatric populations.

Wood, TK, Tilmon, KJ, Shantz, AB, Harris, CK, and Pesek, J. 1999. The role of host-plant fidelity in initiating insect race formation. Evol Ecol Res 1:317-332.

Click here to listen to Graminella nigrifrons.

Graminella nigrifrons is a leafhopper that occurs throughout the eastern United States and a vector of maize chlorotic dwarf virus (MCDV). In the past, I have examined how this virus is acquired and transmitted to corn plants and the role of mating behavior in plant virus epidemiology. Our current work focuses on chorusing behavior in males and how such behavior mediates competition among males for mating opportunities.

Click here to listen to Macropsis fumipennis.

Macropsis fumipennis is an ant attended leafhopper that is a specialist on honeylocust trees. Our long-term goal is to understand the possible role of vibrational signal in attracting ants and how the presence of ants may modify signaling behavior.

Click here to listen to Homalodisca coagulata.

The glassy-winged sharpshooter, Homalodisca coagulata, is an important vector of the bacterium that causes Pierce's disease in grape plants. This leafhopper was introduced to southern California from the southeastern United States several years ago. Populations have expanded at a tremendous rate resulting in outbreaks of Pierce's disease and devastating losses to the grape industry. The United States Department of Agriculture is funding our efforts to determine the role of vibrational signals in the mating behavior of this leafhopper and to determine the feasibility of using vibrational signals to improve the efficiency of traps used to monitor populations.