Bee Pollination in Pumpkin Production

Declines in managed honey bees over the last several years due to Colony Collapse Disorder, coupled with decreased populations of wild bees has led to an interest in assessing the utility of alternative pollinators in fruit and vegetable production. Vine crops are some of the most valuable crops in New York State, and require transfer of pollen by bees for fruit set.  Previous research has shown that on an individual fruit basis, the common eastern bumble bee was the most efficient pollinator of pumpkins, compared with other common species including the honey bee and squash bee. In 2011 I began work on a project that compares pumpkin yield in fields either supplemented with bumble bees, honey bees or nonsupplemented control fields. This work also investigates what role wild bees might have in pumpkin pollination and the landscape factors that might influence their pollination services provided to pumpkin.  

Delimiting Species of Wet Meadow Crane Flies

Uncovering the evolutionary and ecological process that has lead to biodiversity has been, and continues to be one of the most fascinating aspects of biology.  One way to assess such processes is to study the diversity and limits of species.  One group of interest in biodiversity are the crane flies (Diptera: Tipuloidea) because of their extreme diversity (>15,000 described species, representing 10% of all Diptera).  Little is known about the patterns and processes responsible for creating such species diversity in crane flies. 
The first and most basic aspect of clearly defining evolutionary lineages includes a systematic revision of genera or subgenera. As part of my dissertation I described a new subgenus, Neophylidorea and a new species within the subgenus.  

New procedures have opened the door to define species like never before. The species of Neophyildorea did not have distinct limits described in the original descriptions and therefore needed revision to represent distinct evolving lineages. I used four different approaches to delimit species of Neophylidorea. The first was a simple morphological analysis using hierarchical clustering to identify distinct morphological differences between species. The second approach used geometric morphometrics of wing vein features to cluster and discriminate species based on wing morphology. The third approach used fresh specimens from the subgenus to compare and contrast the gene trees from two sets of data: mitochondrial (COI and COII) and nuclear (CAD). Lastly, I used ecological niche modeling to test the niche identity among pair-wise species comparisons. A consensus of these approaches revealed areas where a singular approach may have been misleading, but when taken together they generally limit species similarly. 

Iowa Insect Biodiversity in Unusual Habitats

The Adopt-a-Trap: Iowa Insect Survey Project was born from a paucity of knowledge about the distribution and identity of insects in Iowa. A survey such as this has not been conducted in Iowa since the 1940s, and at that time, it was preliminary at best.  To effectively monitor the impact of environmental change on insect diversity, baseline data on the resident fauna are critical. In 2007, we initiated the Adopt-a-Trap project by sampling insects using Malaise traps at locations across Iowa. Volunteer school groups, individuals, and conservation  organizations are helping with different aspects of the project, including sorting, identifying, and collecting specimens.  The results of the survey will be published as an interactive Webbased learning tool whereby students, educators, and the public will have access to information on the insects of Iowa, including a checklist of insect families. We are currently in the process of sorting, identifying, and sending specimens to amateurs and specialists. Individuals interested in any of our bycatch is welcome to contact me (see homepage for contact info).

This project was funded by the Iowa Department of Natural Resources - Wildlife Diversity Program and State Preserves Board.

Landscape Ecology of Prairie Butterflies

The fragmented Midwestern U.S.A landscape creates prairie remnants embedded in an agricultural matrix, potentially impermeable to dispersing individuals. Conservationists are recognizing the importance of protecting tallgrass prairie along railways because these remnants represent a significant amount of unplowed prairie. These small but relatively common remnants are important from the perspective of right-of-way management and aesthetic beauty, but may also help insure a sustainable future for native species by providing important floral and larval resources for pollinators. We sampled butterflies in 2003 and 2004 at prairie remnants to examine the differences in species composition between linear and block (e.g. prairie preserves) habitats. We used a multiscale approach to determine local and landscape factors on butterfly diversity and community composition. Contrary to our hypothesis, results indicate that linear habitats have a greater total number of species and total number of disturbance-tolerant species than block habitats. Linear and block habitats do not significantly differ in the abundance of habitat-sensitive butterfly species. Correspondence analysis, which examines community composition, clearly separates linear from block habitats. Results from partial least squares regression suggest there are indeed effects of the landscape on butterflies at all scales investigated (local; 0.5, 1.0, 1.5, and 2.0 km). Litter was the local variable most highly correlated with butterfly abundance while roads in the landscape were highly correlated with abundance. Variance partitioning using partial canonical correspondence analysis indicated that landscape variables add additional explanatory power beyond local variables. From this we conclude that although linear habitats harbor a different assemblage of butterflies than block habitats, linear habitats provide important habitat for habitat-sensitive species in Iowa. Understanding landscape scale patterns and processes may enhance our knowledge of butterfly diversity on prairie fragments in the Midwest, USA.