Indoor and outdoor winter activity of Culicoides biting midges,vectors of bluetongue virus,in Italy |
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| Authors: | A. MAGLIANO P. SCARAMOZZINO S. RAVAGNAN F. MONTARSI G. DA ROLD G. CINCINELLI A. MONI P. SILVESTRI A. CARVELLI C. DE LIBERATO |
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| Affiliation: | 1. Istituto Zooprofilattico Sperimentale del Lazio e della Toscana ‘M. Aleandri’, Rome, Italy;2. Istituto Zooprofilattico Sperimentale delle Venezie, Rome, Italy;3. Azienda Unita' Sanitaria Locale (USL) Toscana Sud Est, Arezzo, Italy;4. Azienda USL Toscana Nord Ovest, Massa Carrara, Italy;5. Azienda Sanitaria Locale (ASL) Rieti, Rieti, Italy |
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| Abstract: | Indoor and outdoor winter activity of Culicoides spp. (Diptera: Ceratopogonidae) in central Italy was investigated in order to evaluate whether indoor activity might account for the overwintering of bluetongue virus, as has been hypothesized by some authors. Weekly Culicoides collections were performed at three farms over three consecutive winter seasons. At each farm, two black‐light traps were operated simultaneously, indoors and outdoors. Culicoides were identified using both morphological and molecular means. The Culicoides obsoletus group accounted for 98.2% of sampled specimens. Within this group, C. obsoletus s.s. accounted for 56.8% and Culicoides scoticus for 43.2% of samples. Nulliparous, parous and engorged females were caught throughout the entire winter, both indoors and outdoors. At times, indoor catch sizes outnumbered outdoor collections. A significant inverse correlation was found between minimum temperature and the proportion of indoor Culicoides of the total midge catch, thus indicating that lower outdoor temperatures drive Culicoides midges indoors. High rates of engorged females were recorded indoors, possibly as the result of the propensity of C. obsoletus females to feed indoors. Higher proportions of parous females were found in indoor than in outdoor catches, indicating higher survival rates indoors and, consequently, higher vectorial capacities of midges sheltering indoors compared with those remaining outdoors. |
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| Keywords: | Culicoides bluetongue indoor vectors winter Italy |
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