2008 Annual DSA Meeting Attendees

Pictorial highlights of an odonatological expedition to southern Ecuador, 27 March to 13 April 2008, will be presented. Areas primarily in Azuay, El Oro, Loja, and Zamora-Chinchipe Provinces, including locations in coastal areas, the Andes, and the Amazon drainage, were visited. Approximately 80 species were found.

Research into the evolutionary ecology of long-distance insect migration has been limited by the technical difficulty of effectively tracking large-scale movement, with few species from only a handful of orders studied to date. Here we inferred the scale and direction of individual movement as well as gene flow patterns of adult North American dragonflies (Anax junius) by combining stable isotopic analysis with multilocus genotyping. Using isotopic approaches, we found evidence that individuals flying along major coastal migration corridors are primarily from inland wetlands rather than coastal regions. We found that adult dragonflies migrated an average 8° latitude south, with a net displacement of up to 25° south latitude before capture. Based on genetic data, we inferred that eastern North American represents a single population, and we suggest that southward migration is driven by access to seasonally available fish-free wetlands. Our study is the first to provide empirical evidence of large-scale migration in the order Odonata and describes both intra- and intergenerational movement for the same group of individual insects. By extension, our study also reveals a synergistic new model for studying insect movement.

Dragonfly larvae have been an important contributor to the field of ichnology (the study of traces of organismal behavior). Sanddragons, of the family Gomphidae, create intricate patterns in river sandbars due to their crawling movements. They are adapted to life in swift, sandy rivers. I have shown Progomphus borealis (Odonata: Gomphidae), the Northern Gray Sanddragon, to have the fastest burrowing speed on record, at .72 seconds (time from initial movement on sand surface to coverage with sand) (McMullen in prep.). I observed and quantified sanddragon burrowing behavior on the Big Sandy River in Arizona in Spring 2007. The average burrowing speed was 2.38 seconds, and differed by instar, with smaller instars burrowing more quickly. The average sandbar trail length was 180.97 cm. 37% of sandbar trails crossed themselves at least once. Ichnological studies can be important for species records over time, behavioral studies related to feeding or survival, or studies of habitat distribution.

A few years ago Tanypteryx hageni was considered to be a rare and possibly endangered species. The use of consumer-grade Global Positioning System (GPS), computer mapping programs and the Internet has allowed us to pinpoint the locality of larval/breeding sites. The number of known sites has increased from a few dozen to more than 100 through the use of these technologies.