Development of molecular markers to assess status of native lady beetles in the Midwest

Lady beetles (Coccinellidae) are one of the most charismatic insects that also provide important economic benefits through the biological control of crop pests. This group of predators also offers a great opportunity to study how the introduction of exotic species with a high degree of niche overlap influence native species assemblages. Survey data illustrate that some native lady beetles have declined coinciding with the introduction and establishment of exotic competitors whereas others have remained common. However, survey data can really only gauge major changes, such as when a species shifts from dominate to very rare, but due to year to year and regional variation it is sometimes difficult to know whether a population is actually declining from historic levels. Population genetics can be a powerful tool for gauging the health of a population using low intrapopulation genetic diversity and high interpopulation genetic fragmentation as indicators for decline in a population. Therefore, molecular markers are currently being developed for the four native species: Hippodamia convergens, Coleomegilla maculata, Cycloneda munda and Hippodamia parenthesis. We will use these markers to compare genetic diversity and genetic fragmentation of current population collected from 17 states with historic specimens collected prior to exotic introductions provided by from university museums within each state. The findings of this study will demonstrate the extent to which native lady beetle populations have declined in recent decades.