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Anopheles mosquitoes are the vectors of Plasmodium species, the causative agent of malaria, and a major cause of death in tropical Africa. The distribution of Anopheles species in time and space is a function of ecological factors in a given habitat. This study investigated the distribution of anopheles mosquitoes in the early wet season of 2017, in Keffi Area, Nasarawa State, Nigeria. Mosquito’s collection was carried out in four locations in the study area using two methods: Pyrethrum Spray Catch (PSC) and Centre for Disease Control (CDC) light traps. Indoor and outdoor mosquitoes were collected. All mosquitoes collected were morphologically identified using standard procedures. A total of 973 mosquitoes were collected and identified. This comprised culicines 742 (76%) and anophelines 231 (23%). There was a progressive increase in number of anophelines from April 93 (40.3%) to May 138 (59.2%). Four species of Anopheles mosquitoes were identified in the study area: An.gambiae 221 (95.7%). An.coustani 7 (3.0%), An.squamosus 2(0.9%) and An.pharoensis 1(0.4%).More Anopheles mosquitoes collected showed a statistical significant difference between the 2 months and between indoors and outdoors collection (P<0.05). These findings show the presence of the vector of malaria in the study area during the early wet season and recommends early vector control before and during the season to reduce incidence of malaria in Keffi area of Nasarawa State, Nigeria.

Anopheles mosquito’s resistance to insecticides has been one of the major challenges in eradicating malaria. This study was carried out to determine the susceptibility status of Anopheles mosquitoes to Deltamethrin and Bendiocarb in some communities of Nasarawa Local Government Area of Nasarawa State for four months. The research was carried out at the insectary laboratory of Nasarawa State University Keffi. Center for Disease Control (CDC) bioassay bottle and WHO impregnated papers were used to test the susceptibility of Anopheles mosquitoes. The result shows that Anopheles mosquitoes exposed to Bendiocarb and Deltamethrin using CDC bioassay bottles were susceptible at 15mins, there was no mortality recorded from the control at 30 minutes of exposure. Anopheles mosquitoes exposed to WHO impregnated paper of Bendiocarb and Deltamethrin were susceptible at 60 minutes, mortality was recorded at 24h post exposure time from the control. χ2analysis of Bendiocarb and Deltamethrin insecticides exposed to CDC bioassay bottles was statistically insignificant p>0.05, while χ2 analysis of Bendiocarb and Deltamethrin exposed to WHO impregnated papers was also insignificant p>0.05. These results indicated susceptibility of Anopheles mosquitoes to Bendiocarb and Deltamethrin for the two methods of susceptibility test. The use of these synthetic insecticides in the control of malaria should be encouraged and made available.

Malaria vector control continues to be a major challenge in -Nigeria. Hyptis suaveolens (Bush tea) is one of the traditionally used mosquitos repellent. The effect of methanolic leaf extract of Hyptis suaveolenson larvae of Anopheles gambiae sampled from Keffi, was conducted following the world Health Organization guidelines for laboratory testing. Samples of the leaf were collected and used for test Procedures. Larvae of A. gambiae were exposed to 50, 100, 150,200, 250 and 0.00(control) mg/ml concentrations of leaf extract for 72 hours. Percentage mortality was calculated by using Abott’s formular and lethal concentration (LC50) was determined by a log dosage probit mortality. The result revealed highest and lowest mortality rate of 25.00 ± 0.00 and 1.66± 0.00 for larvae respectively. There were significant differences at (P<0.05) on the mortality rate on the larvae exposed to different concentrations of the plant extracts. The 72 hours LC50 value leaf extracts on larvae was 52.00mg/ml. The result of this study indicated that Hyptis suaveolens possess larvicidal repellant properties and it should be encouraged to be used in communities at zero expense.