Thomas P Agyekum1, John Arko-Mensah1, Paul K Botwe1, Jonathan N Hogarh2, Ibrahim Issah1, Duah Dwomoh3, Maxwell K Billah4, Samuel K Dadzie5, Thomas G Robins6, Julius N Fobil1. 1. Department of Biological, Environmental and Occupational Health Sciences, School of Public Health, University of Ghana, Accra, Ghana. 2. Department of Environmental Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 3. Department of Biostatistics, School of Public Health, University of Ghana, Legon, Ghana. 4. Department of Animal Biology and Conservation Science, University of Ghana, Accra, Ghana. 5. Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana. 6. Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan, USA.
Abstract
OBJECTIVE: This study investigated the effects of temperature on the development of the immature stages of Anopheles gambiae (s.l.) mosquitoes. METHODS: Mosquito eggs were obtained from laboratory established colonies and reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38 and 40°C), and 80 ± 10% relative humidity. Larvae were checked daily for development to the next stage and for mortality. Pupation success, number of adults produced and sex ratio of the newly emerged adults were recorded. Larval survival was monitored every 24 h, and data were analysed using Kaplan-Meier survival analysis. Analysis of variance was used where data followed normal distribution, and a Kruskal-Wallis test where data were not normally distributed. Larval and pupal measurements were log-transformed and analysed using ordinary least square regression with robust standard errors. RESULTS: Increasing the temperature from 25 to 36°C decreased the development time by 10.57 days. Larval survival (X2 (6) = 5353.12, p < 0.001) and the number of adults produced (X2 (5) = 28.16, p < 0.001) decreased with increasing temperature. Increasing temperatures also resulted in significantly smaller larvae and pupae (p < 0.001). At higher temperatures, disproportionately more male than female mosquitoes were produced. CONCLUSIONS: Increased temperature affected different developmental stages in the life cycle of An. gambiae (s.l.) mosquitoes, from larval to adult emergence. This study contributes to the knowledge on the relationship between temperature and Anopheles mosquitoes and provides useful information for modelling vector population dynamics in the light of climate change.
OBJECTIVE: This study investigated the effects of temperature on the development of the immature stages of Anopheles gambiae (s.l.) mosquitoes. METHODS: Mosquito eggs were obtained from laboratory established colonies and reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38 and 40°C), and 80 ± 10% relative humidity. Larvae were checked daily for development to the next stage and for mortality. Pupation success, number of adults produced and sex ratio of the newly emerged adults were recorded. Larval survival was monitored every 24 h, and data were analysed using Kaplan-Meier survival analysis. Analysis of variance was used where data followed normal distribution, and a Kruskal-Wallis test where data were not normally distributed. Larval and pupal measurements were log-transformed and analysed using ordinary least square regression with robust standard errors. RESULTS: Increasing the temperature from 25 to 36°C decreased the development time by 10.57 days. Larval survival (X2 (6) = 5353.12, p < 0.001) and the number of adults produced (X2 (5) = 28.16, p < 0.001) decreased with increasing temperature. Increasing temperatures also resulted in significantly smaller larvae and pupae (p < 0.001). At higher temperatures, disproportionately more male than female mosquitoes were produced. CONCLUSIONS: Increased temperature affected different developmental stages in the life cycle of An. gambiae (s.l.) mosquitoes, from larval to adult emergence. This study contributes to the knowledge on the relationship between temperature and Anopheles mosquitoes and provides useful information for modelling vector population dynamics in the light of climate change.
Authors: Thomas P Agyekum; John Arko-Mensah; Paul K Botwe; Jonathan N Hogarh; Ibrahim Issah; Duah Dwomoh; Maxwell K Billah; Samuel K Dadzie; Thomas G Robins; Julius N Fobil Journal: J Med Entomol Date: 2022-07-13 Impact factor: 2.435
Authors: Thomas Peprah Agyekum; John Arko-Mensah; Paul Kingsley Botwe; Jonathan Nartey Hogarh; Ibrahim Issah; Samuel Kweku Dadzie; Duah Dwomoh; Maxwell Kelvin Billah; Thomas Robins; Julius Najah Fobil Journal: Parasit Vectors Date: 2022-05-08 Impact factor: 4.047