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 P<0.05) Most of the mosquitoes collected were unfed and nulliparous (87.1%). In spite of the high proportion of M. africana, its parous rate was low 0.53 and 0.59 in rice fileld and plantation, respectively. The highest parity was seen in Ae. aegypti (0.81-0.86) and An. gambiae, (0.69-0.68)

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)