Malaria parasites are transmitted in nature through the bites of female Anopheles mosquitoes. However, the vector distribution varies in time and space. This study aimed to determine the species composition, abundance and climatic factors influencing Anopheles mosquitoes in Anambra East Local Government Area of Anambra State, Nigeria from October 2016 to September 2017. Adult Anopheles mosquitoes were collected from indoor and outdoor locations using Pyrethrum Knockdown Collection (PKC) and Human Landing Catch (HLC) Methods respectively. Anopheles mosquito larvae were collected using dipping method. Morphological identification of Anopheles species was carried out using standard identification keys. Climatic data was obtained from Nigerian Meteorological Agency Office in Anambra State. A total of 8181 female Anopheles mosquitoes which comprised 4127 (50.4%) larvae and 4054 (49.6%) adults were collected (P > 0.05) in the study. Four Anopheles species: An. gambiae s. l (70.1%), An. funestus group (18.2%), An. moucheti (6.3%) and An. nili (5.4%) were identified (P < 0.05). In the study area, 2608 (31.9%), 3025 (37.0%) and 2548 (31.1%) Anopheles mosquitoes were collected from Aguleri, Igbariam and Nsugbe respectively; with 100% species overlap. In each selected selected town, the Simpson’s index of diversity was ~2 and Shannon-wiener diversity was ~1. Only An. gambiaes l showed varied seasonal abundance with wet season contributing 67.9% and dry season 32.1% of the overall An. gambiaes. l collection (P < 0.05). The correlation between rainfall and An. gambiae s. l. abundance was significantly strong (r = 0.66; P < 0.05). No significant correlation was found between Anopheles species abundance and temperature as well as relative humidity. The study revealed the preponderance of four Anopheles species: An. gambiae s. l., An. funestus, An. moucheti and An. nili; and rainfall is the only climatic factor that causes temporal change in the abundance of one of the species, An. gambiaes. l. in the study area. Keywords: Anopheles mosquitoes, abundance, temperature, rainfall, relative humidity

Long Lasting Insecticide Nets (LLINs) reduce human-mosquito contact through the provision of physical barrier, repellent effect or mortality effect. This study evaluated the physical integrity and residual effect of insecticides in Perma Net® 2.0 of 6 months, 1 year, 2 years, 3 years and 4 years duration of use. Perma Net®2.0 used were obtained from systematically picked households within Ifite Awka and new Perma Net® 2.0 serving as control were collected from Society for Family Health. Adult mosquitoes were collected from picked households using Pyrethrum knockdown Collection method before the Perma Net® 2.0 were removed. The top and four sides of the nets were examined for presence of holes. Also, net pieces measuring 25cm × 25cm were obtained from Perma Net® 2.0 of different duration and subjected to WHO cone bioassay using Randomized Block Experimental Design. The Culex quinquefasciatus and Aedes aegypti used for the bioassay were collected from breeding sites within Ifite Awka, reared and maintained in an insectary. There was at least one hole in 10%, 30% and 40% of LLINs with 2 years, 3years and 4 years duration of use respectively. Significant differences were found in the physical integrity of the nets (P < 0.05). Culexquinquefasciatus and Aedes aegypti constituted 40.9% and 27.0% of all mosquitoes collected indoors respectively. There was no significant difference in the indoor abundance of the two mosquito species (P >0.05). However, their abundance depended on the duration of LLINs usage (P < 0.05). The mortality effects of16%, 8%, 7%, 5%, 5% and 2% on Culex quinquefasciatus were recorded for Perma Net® 2.0 of 0 month, 6 months, 1 year, 2 years, 3 years and 4 years respectively. The mortality effects of 23%, 12%, 9%, 6%, 5% and 3% on Aedes aegypti were recorded for Perma Net® 2.0 of 0 month, 6 months, 1 year, 2 years, 3 years and 4years respectively. The new LLINs produced significantly highest mortality effect (P < 0.05) on both mosquito species than nets of other duration of usage. The mortality effect of Perma Net® 2.0 on Culex quinquefasciatus, and that on Aedes aegypti were similar (P > 0.05). It shows that Perma Net® 2.0 offer physical barrier more than repellency and mortality effect against Culex quinquefasciatus, and Aedes aegypti.

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