Progress 05/01/11 to 10/31/12
OUTPUTS: Collections of overwintering adult H. convergens from the Sierra Nevada Mountains in California for augmentative releases have been conducted for over a century. Many augmentative releases have targeted pest species in California agricultural systems. But for at least the past 50 years, field collected H. convergens from California have been sold and released east of the Rocky Mountains. Do beetles from California mate with local populations causing potential deleterious effects on eastern populations of H. convergens Previuosly we have documented that there are no reproductive barriers between H. convergens from California and Iowa. Do eastern and western populations of H. convergens in North America show genetic differences that might be related to adaptations to local environmental conditions These genetic questions related to potential inter-population differences among North American populations of H. convergens and the effects of augmentative releases of California beetles are the focus of this proposal. I spent a three month sabbatical leave (May 1, 2011 to July 31, 2011) in the laboratory of Dr. Fred Janzen, Department of Ecology, Evolution and Organismal Biology at Iowa State University. During these 3 months, I conducted a project that examined the ecological genetics of the predatory lady beetle species Hippodamia convergens, a widely distributed species in North America. This predatory species is collected from overwintering sites in California and commercially sold for augmentative releases throughout the United States. One concern that has been raised about this human movement of H. convergens from California is the effect on local populations of H. convergens. The ultimate goal of this project is to determine if there is introgression of California genes into local H. convergens populations. PARTICIPANTS: During this three month sabbatical leave (May 1, 2011 to July 31, 2011), I worked in the laboratory of Dr. Fred Janzen, Department of Ecology, Evolution and Organismal Biology at Iowa State University. One of Dr. Janzen's PhD students (Mr Arun Sethuraman) trained me in laboratory methods of DNA extraction and PCR. Mr. Sethuraman learned a great deal about lady beetle biology and ecology during my sabbatical leave. This leave has initiated a cooperative project on lady beetle genetics with Dr. Janzen at Iowa State University. TARGET AUDIENCES: This project provides preliminary data on differences between western and eastern North American populations of Hippodamia convergens. Target audiences include individuals interested in the conservation of native predatory lady beetles. Individuals in the eastern US who purchase Hippodamia convergens from California would become aware of the potential differences between naturally occurring individuals and those purchased from California. PROJECT MODIFICATIONS: Not relevant to this project.
During this three-month sabbatical leave, I extracted DNA from 4-8 adults from each of 8 populations of H. convergens (Arizona, Arkansas, California, Iowa, 2 locations in Kansas, Kentucky and Oklahoma). Using 10 microsatellite primers developed by a colleague at Ohio State University and PCR techniques, each individual beetle was genotyped at the Iowa State University DNA facility. Sixty-five individuals have been genotyped using these microsatellite markers. Preliminary analyses indicate that the Midwestern populations share many genetic similarities, but no unique markers for the California populations have been discovered. Additional samples are being examined to complete the analysis of the population structure of H. convergens.
- No publications reported this period