Anaija Hardmon, a Biology major from Spelman College, worked in the lab of Dr. Nicole Gottdenker to describe the population structure of an important disease vector.
Abstract: Describing the population structure of zoonotic disease vectors includes understanding their life history strategies and population dynamics, as well as the development of vector-borne diseases, and control strategies for the Chagas disease. This disease is caused by the protozoan parasite Trypanosoma cruzi and transmitted by hematophagous members of the familyTriatominae to humans and mammals alike. The objective of this study was to describe and compare the population structure of the principal vector of Chagas disease in Panama, R. pallescens, across different types of anthropogenic land use. We evaluated the population structure of N= 1123 bugs in total, collected from 5 different habitat types in Panama during the wet seasons of 2008 with N= 759 collected and between 2013-2015 in forest patch, pasture, and peridomestic habitats. There was a significant association between bug stage and habitat type (Chi-squared = 37.3, df = 20, p =0.02). The N1 and N2 nymphs were under-represented in the sample, and the estimated numbers of N3, N4, and N5 stage nymphs were significantly greater in disturbed habitats, with N5 stages being particularly scarce in contiguous forest and cattle pasture where the lowest number of bugs were collected. Nymph: Adult ratios did not significantly differ between habitat types, but tended to be higher in pasture sites. In bugs captured between 2013-2015, more bugs were captured in the Trinidad de las Minas site compared to Las Pavas and there were no apparent inter-annual trends in age structure in these sites. Once errors in detectability are accounted for, this data can be used for the analysis of bug population dynamics within and between habitats.