Thermal preference of Culicoides biting midges in laboratory and semi-field settings.

Autor: Hochstrasser AL; National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zürich, Zürich, Switzerland., Mathis A; National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zürich, Zürich, Switzerland., Verhulst NO; National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zürich, Zürich, Switzerland. Electronic address: niels.verhulst@uzh.ch.
Jazyk: angličtina
Zdroj: Journal of thermal biology [J Therm Biol] 2024 Jan; Vol. 119, pp. 103783. Date of Electronic Publication: 2024 Jan 12.
DOI: 10.1016/j.jtherbio.2024.103783
Abstrakt: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are hematophagous insects, and some species can transmit a plethora of pathogens, e.g., bluetongue virus and African horse sickness virus, that mainly affect animals. The transmission of vector-borne pathogens is strongly temperature dependent, and recent studies pointed to the importance of including microclimatic data when modelling disease spread. However, little is known about the preferred temperature of biting midges. The present study addressed the thermal selection of field-caught Culicoides with two experiments. In a laboratory setup, sugar-fed or blood-fed midges were video tracked for 15 min while moving inside a 60 × 30 × 4 cm setup with a 15-25 °C temperature gradient. Culicoides spent over double the time in the coldest zone of the setup compared to the warmest one. This cold selection was significantly stronger for sugar-fed individuals. Calculated preferred temperatures were 18.3 °C and 18.9 °C for sugar-fed and blood-fed Culicoides, respectively. The effect of temperature on walking speed was significant but weak, indicating that their skewed distribution results from preference and not cold trapping. A second experiment consisted of a two-way-choice-setup, performed in a 90 × 45 × 45 cm net cage, placed outdoors in a sheltered environment. Two UV LED CDC traps were placed inside the setup, and a mean temperature difference of 2.2 °C was created between the two traps. Hundred-fifty Culicoides were released per experiment. Recapture rates were negatively correlated with ambient temperature and were on average three times higher in the cooled trap. The higher prevalence of biting midges in cooler environments influences fitness and ability to transmit pathogens and should be considered in models that predict Culicoides disease transmission.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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