title: Effects of temperature and photoperiod on the development of overwintering immature Culicoides chiopterus and C. dewulfi.
abstract: In areas with harsh winters, several studies have recorded low numbers - or even zero - adult Culicoides during the winter period followed by a population peak in the subsequent spring. This experimental study determined whether temperature, photoperiod, or the combination thereof affect the development of overwintering immature dung breeding Culicoides, resulting in this peak. Temperature had a significant impact on the development period of Culicoides chiopterus (Meigen), 1830 and C. dewulfi Goetghebuer, 1936. In treatments with constant high temperature, emergence occurred shortly after the beginning of the experiment (mean=day 9). In contrast, no individuals emerged from the other two treatments, as long as the temperatures were below 10°C. In these treatments, the emergence of Culicoides started when the temperature exceeded 20°C for some days (mean=day 33). There was no significant difference between the two photoperiods (February or April day length; 9 h:15 h [light:dark] vs. 13 h:11 h). Our results highlight the importance of temperature on the spring emergence of C. chiopterus and C. dewulfi, but the response to the four temperature-photoperiod treatments did not differ between the two species.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Germany. Electronic address: luehken@bnitm.de.
authors.forename: Renke
authors.initials: R
authors.lastname: Lühken
authors.affiliation: Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Steinke
authors.affiliation: Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Germany.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Hoppe
authors.affiliation: Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Kiel
mesh_terms: D000818:Animals; D002519:Ceratopogonidae / Q000254:growth & development / Q000502:physiology*; D017440:Photoperiod; D012621:Seasons; D013696:Temperature
keywords: C. dewulfi; Ceratopogonidae; Cowpat; Culicoides chiopterus; Larvae; Overwintering; Photoperiod; Temperature