Comparative toxicity effect of bush tea leaves (Hyptis suaveolens) and orange peel (Citrus sinensis) oil extract on larvae of the yellow fever mosquito Aedes aegypti

The ethanolic extracts of the orange peel (Citrus sinensis) and bush tea leaves (Hyptis suaveolens) were compared for their toxicity effect on the larvae of the yellow fever mosquito Aedes aegypti collected from disused tyres beside College of Natural Sciences building University of Agriculture, Abeokuta, Nigeria. Eight graded concentrations, 0.9ppm, 0.8ppm, 0.7ppm, 0.6ppm, 0.5ppm, 0.4ppm, 0.3ppm and 0.2ppm of both plant extracts were tested on the larvae. The mean lethal dose LD10, was 0.15 ppm for C. sinensis, 0.01 for H. suaveolens, while LD50 for C. sinensis was 0.4ppm, H.suaveolens 0.60ppm and LD90 for C. sinensis was 0.9ppm and H.suaveolens was 1.45ppm. LD10 for the control 0.65ppm, LD50 0.9ppm and LD90 2.0 ppm. The extract of C. sinensis peel caused higher mortality rate at concentrations 0.8ppm (95%) and 0.3ppm (90%) of the larvae while the extract of H. suaveolens caused high mortality rate on the larvae at concentrations of 0.9ppm (80%) and 0.3ppm (80%). Significant differences were observed between untreated and treated larvae (exposed to either of the extract) at the various concentrations (P< 0.05). Keywords: Citrus sinensis, Hyptis suaveolens, larvae, mortality, Aedes aegypti, NigeriaTanzania Health Research Bulletin Vol. 7(3) 2005: 174-17

Sampling mosquitoes with CDC light trap in rice field and plantation communities in Ogun State, Nigeria

Mosquito species were sampled to determine the mosquito composition and abundance in rice field and plantation communities in Ogun State Nigeria. Mosquitoes were caught once weekly from four selected houses in each of the two communities by means of CDC light traps. A total of 47,501 mosquitoes representing fifteen species were caught in the two communities of which the rice field community accounted for 63.8% of the total catch. Mansonia Africana constituted the most important biting mosquito in the two communities representing 62.1% and 39.1% in rice field and plantation communities, respectively. Other species in decreasing order of abundance were M. uniformis, Anopheles gambiae, Coquilletidia fuscopennata, An. moucheti, An. funestus, An. nili, Culex quinquefasciatus, Eretmapodites chrysogaster, Coq.metallica, Cx annulioris, An. rhodesiensis, Aedes aegypti, An. Squamosus and An. Maculipennis. Seven mosquito species were caught throughout the year but mostly in the months of May to October. Abundance varied significantly between the study sites and between the months (F,1.11 =241.9

A survey of adult mosquitoes in the hostels of the University of Agriculture, Abeokuta, Ogun State, Nigeria

A survey of adult mosquitoes was carried out in the male and female hostels of the University of Agriculture, Abeokuta using two methods: human baits and residual spray catch. Volunteered human baits were positioned indoors and outdoors (with legs exposed) once in a week from 0600-0800 hours and 1800-2000 hours between September 2000 and August 2001. A total of 10,704 Mosquitoes representing four genera - Aedes, Anopheles, Culex and Mansonia - were encountered. Of all the genera collected, Aedes (59%) was the most abundant, while Anopheles and Mansonia spp. Were the least with 13.18 and 13.15%, respectively. From the human bait catch, 4,238 and 3,666 mosquitoes were caught indoors and outdoors, respectively, of which 8.16% of the Anopheles caught were blood fed and 8.14% gravid, 70.25% of the Aedes were fed and 60.5% gravid; 56.0% of the Culex caught were fed and 69.0% gravid; 30.50% Mansonia were fed and 32.0% gravid. The indoor and outdoor catches were not significantly different P>0.001. in all, 2,800 mosquitoes were caught resting indoors of which 36.75% were Aedes spp 29.00% Anopheles sp, 24.75% were Culex and 9.5% Mansonia spp. The Nigerian Journal of Parasitology Vol. 24 2003: 167-17

Horizontal and vertical distribution of mosquitoes (Diptera: Culicidae) in the rainforest of Maromizaha, Madagascar: implications for pathogen transmission to humans and animals

International audienceThe horizontal and vertical distribution of mosquito species was studied in Maromizaha rainforest, Madagascar. In November 2014, horizontal distribution was studied using light traps that were placed in four habitat types, ranging from degraded forest to primary rainforest. In November to December 2016, vertical distribution was studied using light traps placed near to the ground and elevated near the canopy. From the horizontal survey, 476 adults were collected: Uranotaenia (52.10%) and Culex (35.2%) were the most abundant genera. The highest numbers of mosquitoes were observed in the rainforest edge habitat, while the highest mosquito diversity was observed within primary rainforest. From the vertical survey, 276 adults were collected: Culex was the most abundant genus and represented 75.70% of adults caught. Mosquitoes were more abundant in traps placed near the ground than those near the canopy. The highest species diversity was observed near the canopy. The higher abundance of mosquitoes at the forest edge agrees with the role of this zone as an ecotone between intact rainforest and the nearest human habitation. Increased mosquito abundance in lower strata might heighten their contact with particular vertebrate hosts. The presence of vectors in different habitats and in varying elevations likely influences the risk of pathogen transmission between animals and humans in this rainforest

Nigeria Anopheles vector database: an overview of 100 years' research.

Anopheles mosquitoes are important vectors of malaria and lymphatic filariasis (LF), which are major public health diseases in Nigeria. Malaria is caused by infection with a protozoan parasite of the genus Plasmodium and LF by the parasitic worm Wuchereria bancrofti. Updating our knowledge of the Anopheles species is vital in planning and implementing evidence based vector control programs. To present a comprehensive report on the spatial distribution and composition of these vectors, all published data available were collated into a database. Details recorded for each source were the locality, latitude/longitude, time/period of study, species, abundance, sampling/collection methods, morphological and molecular species identification methods, insecticide resistance status, including evidence of the kdr allele, and P. falciparum sporozoite rate and W. bancrofti microfilaria prevalence. This collation resulted in a total of 110 publications, encompassing 484,747 Anopheles mosquitoes in 632 spatially unique descriptions at 142 georeferenced locations being identified across Nigeria from 1900 to 2010. Overall, the highest number of vector species reported included An. gambiae complex (65.2%), An. funestus complex (17.3%), An. gambiae s.s. (6.5%). An. arabiensis (5.0%) and An. funestus s.s. (2.5%), with the molecular forms An. gambiae M and S identified at 120 locations. A variety of sampling/collection and species identification methods were used with an increase in molecular techniques in recent decades. Insecticide resistance to pyrethroids and organochlorines was found in the main Anopheles species across 45 locations. Presence of P. falciparum and W. bancrofti varied between species with the highest sporozoite rates found in An. gambiae s.s, An. funestus s.s. and An. moucheti, and the highest microfilaria prevalence in An. gambiae s.l., An. arabiensis, and An. gambiae s.s. This comprehensive geo-referenced database provides an essential baseline on Anopheles vectors and will be an important resource for malaria and LF vector control programmes in Nigeria