We evaluated the effect of freshly-cut berries, flowers/petals, buds, leaves, stems, and/or seeds from eight plant families on female Aedes aegypti mosquitoes. Plant families included: Apiaceae, Apocynaceae, Asteraceae, Euphorbiaceae, Lamiaceae, Lythraceae, Malvaceae, and Verbenaceae. Standard plastic Petri dishes were used to hold mosquitoes and cut plant parts from 17 plant species. We recorded percent mortality at 24 and 48 h. Three tests per plant part using ten mosquitoes per test were conducted. A 10% sucrose solution served as a food source for mosquitoes during the Petri dish tests. Mosquitoes exposed to freshly-cut plant parts from Apiaceae, Asteraceae and Lamiaceae exhibited over 50% mortality when compared with the controls. Genera of interest include: Chrysanthemum (Chrysanthemum spp. - e.g., Spider Mum), Eryngium (e.g., Eryngium yuccifolium - Rattlesnake Master), Eupatorium (e.g., Eupatorium capillifolium - Dog Fennel), Rudbeckia (e.g., Rudbeckia texana - Texas Cone Flower), Monarda (e.g., Monarda fistulosa - Bee Balm), and Pycnanthemum (e.g., Pycnanthemum muticum - Blue Mountain Mint and P. tenuifolium - Slender Mountain Mint). Mosquitoes exposed to different parts of a chrysanthemum plant (flowers, buds, leaves and stems) exhibited 100% mortality in 24 h. Mosquitoes exposed to cut buds of Pycnanthemum muticum, P. tenuifolium, and Monarda fistulosa exhibited 100% mortality in 24 h. Several species are native to Louisiana and some are considered ethnobotanicals. These studies are part of the Louisiana Native Plant Initiative focusing on the effects of botanical components on mosquito behavior and development.
1 Dept. of Biology and Health Sciences, McNeese State University, Lake Charles, LA; 2 Dept. of Chemistry and Physics, McNeese State University, Lake Charles, LA; 3 Louisiana Environmental Research Center, McNeese State University, Lake Charles, LA
73 • Daniel K. Hasegawa1, Charles E. Beard1, Konstantin G. Kornev2, Peter H. Adler1
Behavior Influences Permeability of the Butterfly Proboscis
The butterfly proboscis traditionally has been viewed as a drinking straw; that is, fluid uptake occurs at the tip, whereas the rest of the proboscis putatively is sealed along the seam of the two halves. To test the permeability of the putatively sealed area, we applied a traceable fluid of water and dye along the semi-transparent proboscis of buckeye butterflies (Junonia coenia). Proboscises were held in a straight position or a flexed position. Drinking was stimulated by applying 15% sucrose to the proboscis tip. Fluid entered the proboscis along the seam of the putatively sealed area within 10 seconds, as visualized with the dye. Significant amounts of fluid entered a flexed proboscis, but not a straightened proboscis, after 30 seconds. Thus, behavioral positioning of the proboscis--flexing it versus straightening it--can influence fluid entry, rendering the entire length of the proboscis permeable or restricting permeability to the tip. The adjustable permeability, compared with the drinking straw model in which uptake is restricted to the tip, might enhance foraging efficiency and contribute to the diversification of Lepidoptera.
1 School of Agriculture Forestry and Environmental Sciences, Clemson University, Clemson, SC; 2 School of Materials Science & Engineering, Clemson University, Clemson SC
74 • Raquel A. Fagundo, Zachary J. Loughman
Feeding Ecology of the New River Crayfish in Anthony Creek, West Virginia
New River Crayfish (Cambarus chasmodactylus) are restricted to the New River drainage of the Central Appalachians. Seasonal dietary habits were investigated in Anthony Creek, West Virginia via dissection of stomachs. Crayfish were collected monthly from May through October 2011. Animals were weighed prior to dissection and following removal of their stomachs to determine stomach mass. Total carapace length was measured and used to place animals in respective demographic groups. Stomach content frequencies were obtained for the following broad categories: organic detritus, inorganic detritus, vegetal, and animal. Food items were identified to the lowest taxonomic level applicable. Additionally, the presence and weight of gastrolyths was noted. General linearized models (GLMs) were utilized to assess the affect of independent variables on feeding preferences. Analysis of proportional stomach content mass indicated that elevated foraging occurred across the population in May and October, with reduced foraging during mid-summer months. Organic detritus was consumed during all sampled months, and was the only item consumed by juveniles. Inorganic detritus was ingested sparingly, with the highest frequency of occurrence in August. Vegetation was primarily consumed by nonreproductive females in the months of June and July. Snails were the predominate animal ingested; benthic macroinvertebrates were rarely consumed. Increased ingestion of exuvia was strongly correlated to two mass molting events occurring in the population in both June and October. When present, exuvia usually occurred alongside gastrolyths. Results indicate New River Crayfish are feeding generalists, and food items vary largely according to season, reproductive state, and molt stage.
Dept of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV
