Corresponding Author Email: abiodunobembe@yahoo.com Phone: +234 8064860782 JASEM ISSN 1119-8362 All rights reserved J. Appl. Sci. Environ. Manage. Vol. 22 (6) 981 –985 June 2018 Full-text Available Online at https://www.ajol.info/index.php/jasem http://ww.bioline.org.br/ja Differential Behaviour of Endophilic Anopheles Mosquitoes in Rooms Occupied by Tobacco Smokers and Non-smokers in Two Nigerian Villages 1,2,4* OBEMBE, A; 2 POPOOLA, KOK; 3 ODUOLA, AO ; 4 AWOLOLA, ST *1 Department of Biosciences and Biotechnology, Kwara State University Malete, Nigeria 2 Department of Zoology, University of Ibadan, Ibadan, Nigeria 3 Department of Zoology, University of Ilorin, Ilorin, Nigeria 4 Molecular Entomology and Vector Control Research Laboratory, Nigerian Institute of Medical, Research, Yaba, Lagos, Nigeria. *Corresponding Author Email: abiodunobembe@yahoo.com Phone: +234 8064860782 ABSTRACT: The behavioural effect of tobacco smoke on endophilic Anopheles mosquitoes was observed in two North Central Nigerian villages. Pyrethrum spray and exit trap collections of mosquitoes were conducted, between April and November 2014, in two different villages where tobacco smoking was common among the residents. Anopheles mosquito samples collected were identified to sibling species level using species-specific polymerase chain reaction. Presence of human blood in the blood-fed mosquitoes was determined by Enzyme-linked immunosorbent assay. Numbers of mosquitoes collected from the rooms inhabited by tobacco smokers and non-smokers were compared using Student’s t-test (p<0.05). At least four times higher exit rates, five times less gravid females and significantly lower numbers of An. gambiae s.l mosquitoes were found in rooms inhabited by tobacco smokers compared to equal sized rooms occupied by non-smokers in each village. Blood feeding rates (77-88%) and human blood indices (0.82-0.87) of mosquitoes were generally high in the habitations of both tobacco smokers and non-smokers. There was predominance of An. gambiae (≥ 86%) species compared to An. coluzzii (≤ 14%) in both villages. Reduced mosquito endophily was observed in the habitations of tobacco smokers compared to the non-smokers. Widespread tobacco smoking habits should be investigated for possible contributions to mosquito behavioural resistance and residual malaria parasite transmission within rural communities. DOI: https://dx.doi.org/10.4314/jasem.v22i6.23 Copyright: Copyright © 2018 Obembe et al. This is an open access article distributed under the Creative Commons Attribution License (CCL), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Dates: Received: 11 May 2018; Revised: 25 June: 2018; Accepted: 30 June 2018 Keywords: Anopheles mosquitoes, Tobacco Smoke, Exophily, Malaria Personal protective measures like the in-house combustions of domestic fuels (Anthony et al., 1992; Bockarie et al., 1994) and repellent plant materials (Seyoum et al., 2002; Moore et al., 2007) have been reported to induce reduced Anopheles mosquito endophily within rural communities. Possible exophilic or irritant effects of other non-targeted human practices on indoor resting mosquitoes should be profiled. Otherwise, such induced exophilic effects shown by low numbers of indoor mosquitoes may be erroneously considered as positive results from an applied intervention or the existence of generally low vector biting densities within a specific community. Here, we report differential Anopheles mosquito exophily found between rooms inhabited by tobacco smoking and non-smoking single-adult-male residents within the same villages in Kwara State, Nigeria. MATERIALS AND METHODS Description of study area: This observation was noticed by serendipity during monthly pyrethrum spray collections (WHO, 2003) of mosquitoes in two different villages; Akorede (N 08 o 40.048 E 004 o 31.370) and Lumoh (N 08 o 38.001 E 004 o 33.740) located within Moro Local government area of Kwara State, Nigeria. Mud houses (14 in Akorede and 12 in Lumoh) spread across each village had separate kitchens, corrugated iron roofing and no ceilings. Community residents were interviewed during mornings of mosquito collection to confirm the numbers of room occupants and absence of the use of any personal protective measures including bed nets. Male household heads in each village had separate sleeping rooms from other members of the households. Some of the male household heads were observed to smoke cigarettes, with their doors and windows closed, within the early morning hours (6.30 – 7.30am). The closed smoke-filled rooms were usually the last to be surveyed in the two different villages because the inhabitants were the last to exit the rooms to allow for mosquito collections. At least 58% of the singly occupied rooms (14 in Akorede and 12 in Lumoh) had a cigarette smoking male household head as the only occupant. Many of the residents smoked