298 - Development of a Water-Jacketed Membrane Feeder Repellent Testing System for Black Flies (Diptera:Simuliidae)

Abstract: The University of Georgia Black Fly Research and Resource Center maintains the only known colony of black flies (Diptera: Simulidae). Specimens from this colony were used to develop an in-vitro repellent testing system. Simulium vittatum is autogenous, depositing their first batch of eggs without a blood meal. By using post-ovipostion females we take advantage of their enhance propensity to bite. The repellent testing system is based on a Rutledge-style water-jacketed glass membrane feeder design. Every 2 hours up to 12, 40 new post-oviposition female black flies were exposed to treated latex membranes. An observation frame was developed to allow instant, visual confirmation of the biting/repellency behavior. The membranes were treated with 15ul of one of three commercially available insect repellents. The repellents tested were: Repel® Plant-Based Lemon Eucalyptus Insect Repellent 2 (30% Oil of Lemon Eucalyptus [OLE]), OFF!® Botanicals Insect Repellent IV (10% p-Menthane-3, 8-diol [PMD]), and Zevo™ On-body (20% IR3535®). Untreated membranes served as a control. In lieu of blood, the membrane feeders were filled with 10ml of 10% sucrose. Three replications of each repellent treatment were conducted. Products OFF!® Botanicals Insect Repellent IV (10% PMD) and Zevo™ On-body (20% IR3535®) had negative correlations between repellency rate over time [IR3535 (m = -6.64), PMD (m = -5.28)] while Repel® Plant-Based Lemon Eucalyptus Insect Repellent 2 (30% OLE) did not exhibit a change in repellency rate over the 12 hour testing period [OLE (m = 0)].