Bionomics of livestock‐associated Culicoides (biting midge) bluetongue virus vectors under laboratory conditions

Abstract

This research contributes to knowledge of the basic bionomic parameters of vector and non-vector Culicoides species. Field-collected gravid C. imicola and Obsoletus complex showed the longest lifespans in laboratory conditions. Culicoides paolae and C. circumscriptus seemed to be the most suitable species for laboratory rearing in view of their high oviposition rates, short lifecycles, long adult lifespans and female-biased sex ratios.

Development and lifespan of Culicoides obsoletus s.s. (Meigen) and other livestock‐associated species reared at different temperatures under laboratory conditions

“…The total percentage of oviposition on artificial substrate at different temperatures recorded in this study (18, 25 and 30 °C) indicates that the substrate and the technique were adequate to obtain eggs from field‐collected females (Barceló & Miranda, 2017). Even still, less than 20% of total gravid females collected in both farms managed to lay eggs (Obsoletus complex and the ornithophilic species C. circumscriptus , C. paolae and C. cataneii ) and only two of them (Obsoletus complex and C. circumscriptus ) oviposited eggs at the three temperatures.…”

“…The phenomenon of high abundance of gravid females, especially of C. circumscriptus collected in both farms and also in that of Barceló & Miranda (2017) remains unknown, but was probably related with long gonotrophic cycles of this species (Carpenter et al ., 2006).…”

“…Even still, less than 20% of total gravid females collected in both farms managed to lay eggs (Obsoletus complex and the ornithophilic species C. circumscriptus , C. paolae and C. cataneii ) and only two of them (Obsoletus complex and C. circumscriptus ) oviposited eggs at the three temperatures. The vector species C. imicola and Culicoides newsteadi Austen, as well as the non‐vectors C. jumineri , Culicoides puncticollis (Becker), C. parroti , C. brunnicans and Culicoides comosioculatus Tokunaga were less abundant in samples and did not succeed in ovipositing; however, C. imicola and C. newsteadi have been previously reared under laboratory conditions (Barceló & Miranda, 2017). These low oviposition rates could be linked with the eggs absorption of some Culicoides females related with the unsuitability of the artificial substrate (Carpenter et al ., 2001).…”

“…Gravid females were selected on a chill table (Dyce, 1969) and kept individually in 64 × 50 mm cardboard boxes (Watkins & Doncaster®). Boxes were provided with 5 cm plastic Petri dish at the bottom with moistened cotton wool and filter paper as substrate for oviposition (Barceló & Miranda, 2017) and paper pads with 10% sucrose solution were used to provide a sugar meal, mixed with 0.2% of Nipagin (Methyl p ‐hydroxybenzoate) [AppliChem GmbH (Darmstadt, Germany) & Panreac Química SLU (Barcelona, Spain)] as an antibiotic to prevent fungal proliferation (Veronesi et al ., 2009). After oviposition, eggs from each single gravid female were counted and transferred using a small brush to 100 mm Petri dishes filled with 10 mL of 2% European Bacteriological Agar (CONDA® Laboratories, Pronadisa, Spain) gel medium and humidified daily to prevent desiccation (Boorman, 1985).…”

The applicability of spectrophotometry for the assessment of blood meal volume inartificially fed Culicoides imicola in South Africa

“…For example, Veronesi et al . (2009) reported a mean batch size of only 6.8 eggs/ C. imicola female in midges fed through a membrane compared to batch sizes of 53–263 eggs reported in field collected gravid females (Walker & Boreham, 1976; Braverman & Linley, 1994; Barceló & Miranda, 2018). The mean blood meal volume ingested during artificial feeding either determined by spectrophotometry, 0.06 μL, or by weighing, 0.07 μL, may therefore underestimate the field situation.…”