Kenneth F. Haynes
Professor, Insect Behavior/Chemical Ecology
Ph.D. University of California, Davis (1982)
Department of Entomology
S-225 Agricultural Science Center N
University of Kentucky
Lexington, KY 40546-0091
Ph: 859.257.1618
Fax: 859.323.1120
Email: khaynes@uky.edu
Mating behavior in insects is often mediated by chemical signals called pheromones. In most moths and many other insects, a species-specific pheromone blend is released by the female. The signal is detected by a downwind male via sensory receptors on the antennae. Males then initiate upwind flight toward the pheromone source. When the male arrives at the source of the pheromone, courtship and mating occurs. Pheromonal blends often determine the species-specificity of the emitted signal. Studies of these types of chemical communication systems could lead to an understanding of the process of speciation. In addition, synthetic pheromones can be used in a variety of ways to control insect pests.
My research program focuses on genetic, physiological, behavioral and evolutionary aspects of chemical communication in insects. I am interested both the evolutionary origin and the diversification of species-specific pheromones. I expect that these studies will contribute to an understanding of speciation and the potential to use pheromones for insect pest management. Within my program we analyze chemical and behavioral aspects of pheromone signaling, and characterize physiological and behavioral components of the response.
Graduate Student Projects
Publication List
Research Priorities
Speciation and the evolution of sex pheromone blends
Chemical signals often mediate the reproductive behaviors of insects. These sex pheromones are nearly ubiquitous in moths, with females producing a blend of chemical compounds that are detected by males of the same species. Typically males will only respond to the specific blend emitted by the female. When synthetic pheromones are used in agriculture to disrupt mating, they impose selection on the communication system, leading to the potential for the evolution of resistance to this control tactic. We will study the potential for such evolutionary changes in the pheromone communication system of the cabbage looper moth. Within this species, we have discovered a single gene mutation that results in a dramatically different pheromone blend. In addition, we have determined that there are males with different response specificities to these pheromone blends. We will determine if there are inherited differences in the specificity of the males behavioral responses to different pheromone blends. Such variation would be an essential prerequisite for changes in the communication system. We will also determine if mating disruption using a typical pheromone blend results in selection favoring females with different pheromone blends, and/or males with atypical behavioral response specificities. We expect that these studies will give us new insights into the potential for evolution of resistance to synthetic pheromones when they are used to control mating behavior. By understanding this potential, we hope to preserve the utility of pheromones when they are used to control mating behavior. This work involves a collaboration with Dr. Allen Moore (Entomology, Manchester, England).
Origins of chemical communication
The female southern masked chafer, Cyclocephala lurida (a scarabaeid beetle, shown right), releases a sex pheromone that attracts conspecific males. The presence of the same chemicals in the larval stage of this insect suggests that pheromone signals may have originated from larval odors. This work currently involves a collaboration with Dr. Daniel A. Potter (Entomology, University of Kentucky), Dr. Jerold Meinwald (Chemistry, Cornell), Dr. Athula Attygalle (Chemistry, Cornell), and Dr. Walter Leal (Japan).
Aggressive chemical mimicry of prey pheromones
Evolutionary specialization of a predator on a few prey species has potential advantages and disadvantages. Such a predator can evolve to become highly efficient at finding, handling, and utilizing its prey, but the predator becomes dependent on availability of these particular prey, which could be costly in years of prey scarcity. The bolas spider Mastophora hutchinsoni (shown right) is an extremely specialized predator. The adult female emits chemical attractants that mimic the sex pheromones of its moth prey, a form of aggressive chemical mimicry. The spider exploits the inherent mate-finding behavior of its victims, which are male moths. Two moth species, one active early at night and the other late at night, account for more than 90% of this predator's prey; only two other moth species are ever captured. When prey approach the spider, it strikes them with a sticky ball at the end of a short thread. This capture device, called a bolas, represents a highly reduced web that the spider swings with one of its forelegs. To attract mates, female moths of the two principal prey species release blends of chemical compounds that do not overlap in their components. The spider could produce a master blend of all these components, but preliminary results indicate this would make the attractant much less efficient in luring one of the spider's two principal prey species. If the spider could adjust its attractant blend to predictable and unpredictable variation in prey abundance, it would be a much more efficient predator and could minimize a major disadvantage of prey specialization. In this research, we propose to use a combination of chemical, electrophysiological, and behavioral approaches to determine if this bolas spider shows flexibility in its behavior or mimetic signal to improve its hunting effectiveness. Specific questions to be addressed include the following: (1) Does the spider's emitted signal change over the course of a night to correspond with the predictably different diel patterns of sexual activity of its principal prey species? (2) Does the emitted signal vary seasonally to correspond with predictable changes in abundance of its prey species? (3) Do hunting tactics and the emitted signal vary plastically with unpredictable prey availability? Studies of this system will lead to an understanding of tradeoffs involved in the evolution of exploitation of chemical communication and the role of behavioral plasticity in minimizing the costs of specialization.
This work involves a collaboration with Dr. Kenneth V. Yeargan (Entomology, University of Kentucky).
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