5/22/2016  |   10:30 - 10:45   |  311-312

CADDISFLY BEHAVIORAL RESPONSES TO DRYING CUES IN TEMPORARY PONDS: IMPLICATIONS FOR EFFECTS OF CLIMATE CHANGE Organisms in high elevation ponds are vulnerable to climate-change-induced alterations in snowpack, snowmelt, and evaporation. Caddisfly larvae, Asynarchus nigriculus live in high-elevation temporary ponds, and engage in mob cannibalism to supplement detritus diets to escape from drying basins. Extraordinarily early drying of those ponds motivated 2 mesocosm experiments to test effects of drying on aggressive behaviors between caddisflies that are precursors to cannibalism and on development time to pupation. We manipulated caddisfly density to simulate crowding during pond drying and reduced water levels and supplemented protein to mimic the dietary benefits of cannibalism. Frequency and duration of agonistic encounters increased as a function of larval density and were higher in drying than nondrying treatments, especially in the absence of supplemental protein. Pupation occurred earlier in high- than low-density treatments and earlier with than without supplemental protein. Our findings provide evidence that both declining water levels and crowding are cues enabling caddisflies to adjust behavior and development in drying habitats. However, early drying events exceeding the limits of this flexibility may result in extirpation from habitats that historically supported this species.

Scott Wissinger (Primary Presenter/Author), Allegheny College, swissing@allegheny.edu;


Jessica Lund ( Co-Presenter/Co-Author), University of Wisconsin, Jessicaolund@gmail.com;


Bobbi Peckarsky ( Co-Presenter/Co-Author), University of Wisconsin, bobbipeckarsky@gmail.com;


Presentation:
This presentation has not yet been uploaded.

5/22/2016  |   10:45 - 11:00   |  311-312

SPECIES-SPECIFIC FEEDING PATTERNS OF CORIXIDS (HEMIPTERA: CORIXIDAE) AS INDICATED BY STABLE ISOTOPE ANALYSIS Corixids (Hemiptera: Corixidae) are a diverse group of aquatic insects that exhibit variable feeding habits, yet are often treated as having homogenous diets in food web studies. Using a diverse corixid assemblage (Callicorixa audeni, Cenocorixa bifida, C. dakotensis, Cymatia americana, Hesperocorixa atopodonta, H. vulgaris, Sigara bicoloripennis and S. decoratella) collected from wetlands near Saskatoon, Saskatchewan, we determined the carbon sources and trophic positions of different species using stable isotope ratios of carbon, delta13C, and nitrogen, delta15N. All species relied on a mix of pelagic and benthic carbon sources, with an overall heavier reliance on the benthic source pathway, except for H. atopodonta, which was completely reliant on 13C-depleted plankton. Carbon source usage varied significantly among sites for all species except C. bifida. Trophic position estimates ranged more than a full level across species, with C. dakotensis occupying a predatory niche. Other species were intermediate between the primary and secondary consumer levels, and differed significantly in trophic position among sites. These results indicate plastic feeding behaviors within and among species that could be advantageous in variable habitat conditions.

Stephen Srayko (Primary Presenter/Author), University of Saskatchewan, shs176@mail.usask.ca;


Iain Phillips ( Co-Presenter/Co-Author), University of Saskatchewan, iain.phillips@wsask.ca;


Tim Jardine ( Co-Presenter/Co-Author), University of Saskatchewan, tim.jardine@usask.ca;


Doug Chivers ( Co-Presenter/Co-Author), University of Saskatchewan, doug.chivers@usask.ca;


Presentation:
This presentation has not yet been uploaded.

5/22/2016  |   11:00 - 11:15   |  311-312

POPULATION STRUCTURE OF BURROWING BOG CRAYFISHES (FALLICAMBARUS SPP.) IN SOUTH ALABAMA, USA A fundamental issue in conservation ecology is determining connectivity between populations to assess levels of genetic diversity. Prior studies with endemic crayfishes in southeastern US streams have demonstrated low levels of population connectivity. Because of their isolated nature and presumably limited dispersal ability, burrowing crayfish potentially show even lower levels of connectivity. The objective of this study was to assess the population genetic structure of two narrowly distributed burrowing crayfishes in south Alabama (Fallicambarus burrisi and F. byersi). We collected chelae tissue from 46 F. byersi and 106 F. burrisi from 17 sites across the species’ range. Using AMOVA based on mitochondrial cytochrome c oxidase subunit I (COI) gene sequences, there were significant differences in structuring between drainages, between sites, within drainages, and within site for F. burrisi while F. byersi had no significant differences at any level. This implies that there are differences in evolutionary history between these two similar species. These results also suggest cryptic genetic diversity and phenotypic similarity within and between nominal species, significant genetic isolation and extremely low levels of connectivity between populations.

Mallary Clay (Primary Presenter/Author), Auburn University, mmc0024@auburn.edu;


Presentation:
This presentation has not yet been uploaded.

5/22/2016  |   11:15 - 11:30   |  311-312

PREVALENCE AND SPATIAL DISTRIBUTION OF WOLBACHIA WITHIN AQUATIC INSECTS OF THE MISSOURI RIVER AND ASSOCIATED DRAINAGES Wolbachia is a genus of intracellular bacteria found within the reproductive systems of insects that manipulates those systems of their hosts. While current estimates of Wolbachia prevalence suggest that it infects 40-60% of all insects, these estimates are based almost entirely on terrestrial insects. No systematic survey of Wolbachia in aquatic insects has been performed. Thus it is unclear whether these estimates apply to major aquatic insect taxa. Data lacking on several prominent insect taxa poses a problem for models that predict the global estimate of Wolbachia. To estimate Wolbachia infection frequency among aquatic insect species, we tested 251 insects from the Missouri River plus 9 tributaries. We combined this with a beta binomial model that corrects for potential false negatives. Results indicate that up to >70% of aquatic insect species carry Wolbachia including members of Odonata, Trichoptera, Diptera, Hemiptera and Plecoptera. Trichoptera represents a newly identified infection. These results indicate that Wolbachia is widespread among aquatic insects. This is particularly important given the ongoing introductions of Wolbachia infected mosquitoes as a biocontrol method in aquatic ecosystems.

Eric Sazama (Primary Presenter/Author), University of South Dakota, ericjsazama@gmail.com;


Carmelita Shouldis ( Co-Presenter/Co-Author), University of South Dakota, esaz57@hotmail.com;


Scot Ouellette ( Co-Presenter/Co-Author), University of Nebraska Medical Center, scot.ouellette@unmc.edu;


Jeff Wesner ( Co-Presenter/Co-Author), University of South Dakota, Jeff.Wesner@usd.edu;


Presentation:
This presentation has not yet been uploaded.

5/22/2016  |   11:30 - 11:45   |  311-312

FRESHWATER POLYCHAETES IN THE DETROIT RIVER OF THE LAURENTIAN GREAT LAKES: ABUNDANCE AND LIFE-HISTORY Freshwater polychaetes are relatively rare and little-studied members of the benthos communities. This study presents changes in long-term abundances of M. speciosa over five decades of time and seasonal life-history characteristics in 2009-2010 and 2012-2013. Life-history was derived from; abundance estimates, length-frequency distributions, presence/absence of constructed tubes and young-of-the-year (YOY) in tubes, maturation of YOY, sexual maturity of individuals, and number of YOY in tubes. Long-term abundances decreased in successive time periods between 1961 and 2003 (mean range= 57,570 to 2,583/m2) but little change occurred between 2003 and 2013 (mean = 5007/m2; range/y = 2,355 to 8,216/m2: n = 6 periods). Seasonal abundances varied substantially between sites and years but overall, abundances were low in spring, increased in summer, and decreased in fall. The life span was about 10 months-plus and appeared to be directly dependent on surface-water temperatures. These results agree with, and compliment, laboratory studies of M. speciosa in the Pacific Northwest where M. speciosa caused substantial fish mortalities (40-80% of chinook salmon).

Don W Schloesser (Primary Presenter/Author), U.S. Geological Survey, Great Lakes Science Center, dschloesser@usgs.gov;


Dave M Malakauskas ( Co-Presenter/Co-Author), Francis Marion University, dmalakauskas@fmarion.edu;


Sarah J Malakauskas ( Co-Presenter/Co-Author), Francis Marion University, smalakauskas@fmarion.edu;


Presentation:
This presentation has not yet been uploaded.

5/22/2016  |   11:45 - 12:00   |  311-312

FINDING THE SPATIAL CONNECTION BETWEEN PRODUCTIVE LARVAL HABITATS AND ADULT NUISANCE SWARMS OF THE BLACK FLY SIMULIUM JENNINGSI (DIPTERA: SIMULIIDAE) The black fly Simulium jenningsi (Diptera: Simuliidae) is found in its adult form throughout western Maryland, but is only reported to form severe nuisance swarms by residents in a few communities. We hypothesized the clustered nature of the nuisance swarms were spatially associated with lotic regions of high larval productivity, and that these lotic habitats would be characterized by high flow and nutrient-rich seston. Larvae were qualitatively sampled in 2013 and 2014 to determine which rivers contained S. jenningsi larvae. After determining the main larval source to be the Potomac River, an artificial substrate sampling method was developed in 2015 to determine the density of colonizing larvae at sites above and below the confluence with the Shenandoah River. Seston samples and flow measurements were taken during each substrate deployment. Results from the artificial substrate trials suggest flow had a significant impact on number of colonizing larvae, but there was no difference in colonization density or seston chlorophyll-a content above and below the confluence. Future studies will examine the use of satellite imagery to determine sites of high larval density.

Rebecca Wilson (POC,Primary Presenter), University of Maryland, rcwilson@umd.edu;


William Lamp ( Co-Presenter/Co-Author), University of Maryland, lamp@umd.edu;


Presentation:
This presentation has not yet been uploaded.