Journal of Bacteriology & Parasitology

Laboratory oviposition studies of Culicoides species (Diptera: Ceratopogonidae) associated with orbivirus transmission in the US

4^th International Conference on Parasitology

September 01-02, 2017 | Prague, Czech Republic

Dinesh Erram and Nathan Burkett-Cadena

Florida Medical Entomology Laboratory, University of Florida IFAS, 200 9th Street SE, Vero Beach, FL 32962, USA

Scientific Tracks Abstracts: J Bacteriol Parasitol

Abstract:

Statement of the problem: Culicoides insects (biting midges or no-see-ums) transmit pathogens such as bluetongue virus and epizootic hemorrhagic disease virus to ruminants, exerting a significant economic impact on animal agriculture in the US and other parts of the world. However, very little information exists on various fundamental biological aspects of Culicoides species complicating the implementation of effective midge management strategies. In this study, we examined the attractiveness of various natural sources on the oviposition of Culicoides insignis Lutz and C. stellifer Coquillett (confirmed/suspected vectors of BTV/EHDV particularly in southeastern US) under laboratory conditions. Methodology: Culicoides insignis and C. stellifer females were collected from the field using CO2 baited-CDC UV-light traps. Midges were blood-fed on live chicken and were allowed to oviposit on substrates containing mud or vegetation from a breeding site against a control of moist cotton (two-choice tests). Findings: Overall, a high proportion of midges (both species) (�?� 75.0%) preferred to oviposit on substrates with breeding site mud or vegetation over control substrates. C. stellifer deposited significantly high number of eggs on substrates containing breeding site mud (40.7 ± 14.2) (mean ± SEM) and vegetation (38.2 ± 9.5) than control substrates (�?� 5.8). The proportion of egg batch deposited by individual females was significantly high during trials with breeding site vegetation (100.00 ± 0.00%) than with mud (57.9 ± 13.2%). Similarly, C. insignis deposited greater number of eggs on substrates with breeding site mud (48.8 ± 15.0) than control substrates (16.5 ± 6.6). Further experiments are in progress. Conclusions and significance: A variety of volatile and/or contact cues emanating from different sources in the habitat serve as oviposition attractants/stimulants in Culicoides species. A better understanding of Culicoides oviposition preferences/cues may lead to development of novel midge control strategies by targeting gravid females and/or better midge survey methods.

Biography :

Dinesh Erram, PhD, focuses on understanding various biological aspects of arthropods of medical and/or veterinary importance with an aim to design/improve integrated management strategies against target species. Hemorrhagic disease in ruminants is a significant threat to animal agriculture in the US and other parts of the world. This disease is caused by orbiviruses, which are transmitted by Culicoides insects commonly referred to as biting midges or no-see-ums. Unfortunately, effective midge control strategies do not exist currently. Our ongoing research on the oviposition of C. insignis and C. stellifer provides the first insight into oviposition preferences and potential cues involved in oviposition site selection in these species, which may in the long run provide clues towards their control by potentially targeting gravid females and/or larvae.