Master of Science (MS)
The seasonal abundance and species composition of ceratopogonids (Diptera: Ceratopogonidae) in East Baton Rouge parish was described from light trap collections at 15 sites. A total of 4,968 collections were processed, and 48,667 ceratopogonids were collected from 20 November, 2002 through 25 November, 2004. Three genera of ceratopogonids (Forcipomyia Meigen, Atrichopogon Kieffer, and Culicoides Latrielle) and a total of 18 species of the genus Culicoides were identified. Ceratopogonids had distinctive spring and fall population peaks. Ceratopogonids were collected in every month during the study, with the exception of February 2004. These results suggest that certain species of Culicoides may overwinter as adults in Louisiana, which could provide an important maintenance mechanism for arboviruses. New information on the other four species of biting midges was obtained. This study represents the first report of Culicoides edeni Wirth and Blanton in Louisiana and the first description of the seasonal abundance of Culicoides neopulicaris Wirth in Louisiana. The data also showed that Culicoides debilipalpis Lutz and Culicoides stellifer Coquillett have longer seasonal activity periods than previously reported for Louisiana. Pools of specimens of ceratopogonids collected from the 15 sites in East Baton Rouge parish in 2004 were prepared for West Nile virus (WNV) detection assays. Eighty-nine pools with specimens of Culicoides, four pools with specimens of Atrichopogon, and two pools with specimens of Forcipomyia were processed. One pool containing specimens of Culicoides arboricola Root and Hoffman, two pools containing specimens of Culicoides biguttatus Coquillett, and two pools containing specimens of C. stellifer tested positive for WNV RNA. This is the second study in which WNV has been detected in field collected ceratopogonids in the United States. The estimated numbers of plaque-forming units (PFU) found in the pools of specimens of Culicoides were within the range of PFU found in known mosquito vectors of WNV. Based on host availability specimens of C. stellifer, C. biguttatus, and C. arboricola feed on both birds and/or mammals, suggesting that these species could play an important role in transmitting WNV from birds to mammals. These results indicate that the importance of biting midges as vectors of WNV should be investigated in future studies.
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Sabio, Isidra Joselina, "Seasonal abundance and detection of West Nile virus in ceratopogonids (Diptera: Ceratopogonidae) in East Baton Rouge Parish, Louisiana" (2005). LSU Master's Theses. 3494.
Lane D. Foil