Unknown parasitoid wasp reared from a Neodiprion sawfly. Photo courtesy of Ian Fefchak-Robinson.
Divergence across trophic levels
A primary goal of the Bagley lab is to describe the community of natural enemies associated with the pine sawfly genus Neodiprion. The genus contains a fair number of pest species, and so has unusually abundant natural history information available. In recent years, genomic resources have also been developed for this group, and population genomic patterns of several widespread species have been evaluated. This gives us a unique opportunity to determine if and when divergence in sawflies has impacted other trophic levels, including parasitoids (lethal parasites) and viruses. This work will use a combination of natural history records, classification of natural enemies reared from previous and future sawfly collections, and the development of genomic resources/genome-scale datasets.
Parasitoid wasps are likely one of the most species-rich groups in organisms on earth, as most of them specialize on a single or small handful of hosts. Figure modified from Forbes et al. 2018.
Evaluating the “Pie of Life”
Although it seems like something biologists should know, a longstanding question is which groups of organisms have the most species. The tried and true method of finding and counting species is to collect, investigate, and formally describe them. However, there are multiple issues with this approach, especially for organisms that are small or have complex life cycles that limit their apparency in the environment. We seek to use a combination of literature reviews, collections of insects from various habitats, and next-generation sequencing to estimate the relative diversity of different groups of organisms. Of particular focus are insects, nematodes, mites, fungi, and bacteria; all of which harbor vast numbers of undescribed species. Additional goals of this project include describing the ecological axes that are associated with increased species diversity, and uncovering cryptic relationships between taxa. This work is performed in conjunction with collaborator Andrew Forbes (UIowa).
A female sawfly adult ovipositing. Oviposition is a precarious behavior for sawflies, as they cut literal pockets inside of pine needles. If the female cuts too deeply – the eggs dry out and die.
Investigating the role of host use between pine sawfly populations
The project that started it all! Biologists have long wondered why there are so many plant-feeding insects. A leading hypothesis proposes that shifts and subsequent adaptations to new host plants may directly drive insect speciation. To investigate this question, we pair ecological and genomic information to determine what role utilizing different pine host plants plays in driving divergence between populations of the widespread redheaded pine sawfly, Neodiprion lecontei. I investigate this question with sawflies collected from across eastern North America, which allows evaluation at a variety of different temporal and spatial scales. This work is performed in conjunction with collaborator Catherine Linnen (Kentucky).