A study on the bioremediation potentials of the earthworm Hyperiodrilusafricanus (Beddard) in soil contaminated with crude oil was investigated. Dried and sieved soils were contaminated with 5 ml each of crude oil with replicates and inoculated with earthworms and monitored daily for 12 weeks. Physicochemical parameters such as pH, total organic carbon, sulfate, nitrate, phosphate, sodium, potassium, calcium and magnesium were determined using standard procedures. Total petroleum hydrocarbon (TPH) was determined using atomic absorption spectrophotometer (AAS), while BTEX constituents and earthworms tissues were analyzed using Gas Chromatography with Flame Ionization Detector (GC-FID). The results showed that the earthworm significantly enhanced the physicochemical parameters of the contaminated soil resulting in a decrease of the total organic carbon (56.64 %), sulfate (57.66 %), nitrate (57.69 %), phosphate (57.73 %), sodium (57.69 %), potassium (57.68 %), calcium (57.69 %) and magnesium (57.68 %) except pH (3.90 %) that slightly increased. There was a significant decrease in the TPH (84.99 %), benzene (91.65 %), toluene (100.00 %), ethylbenzene (100.00 %) and xylene (100.00 %). Analyses of the tissues of the earthworm at the end of the experiment showed that the earthworms bioaccumulated/biodegraded 57.35/27.64 % TPH, 38.91/52.73 % benzene, 27.76/72.24 % toluene, 42.16/57.85 % ethylbenzene and 09.62/90.38 % xylene. The results showed that the earthworms H. africanus could be used to bioremediate moderately polluted soil with crude oil contamination in the Niger Delta region of Nigeria.

The influence of larval diet, body weight at imago, size of blood-meal and age on the fecundity of Culex quinquefasciatus was investigated. The mean weights of mosquitoes at adult.emergence varied significantly with larval diet. Larvae reared on liver diet grew into heavier adults, and produced more eggs than those reared on milk. The volume of blood engorged by the female mosquitoes apparently remains constant during each gonotrophic cycle. However, the number of eggs produced is a function of both the blood-meal size and age of the mosquitoes. These results were discussed in relation to the need for full knowledge of the reproductive potential of this species of filaria vectors.Resume-L'influence due regime larvaire, du polds (du corps) a imago, de la quantity due sang suce et de l'age sur la recondite de Culex quinquefasciatus a ete etudiee.Le poids moyen des moustiques quand ils emergent a l'age adulte varie considerablement selon le regime larvaire. Les larves eleve'es sur un regime de foie sont devenues des adultes pesant plus lourd et produisant un nombre plus ilevi d'oeufs que celles elevens sur un regime de lait. Le volume de sang englouti par les femelles demeure apparemment inchange tout le long de chaque cycle gonotrophique. Cependant, le nombre d'oeufs produit depend non seulement de la quantite due sang suce mais aussi de l'age physiologique des moustiques.Ces resultats ont ete examines par rapport a la necessite d'avoir une connaissance plus complete due potentiel reproductif de cette espece de vecteurs filaires.

This study investigated the larvicidal activities of methanol leaf extracts of six tropical plants against Anopheles gambiae s.l mosquitoes. 10 healthy laboratory stabilized larvae were treated with extracts of Ocimum gratissimum, Chromolaena odorata, Terminalia catappa, Carica papaya, Vernonia amygdalina and Cymbopogon citratus with different concentrations (0, 200, 400, 600, 800 and 1000 ppm) for 24, 48 and 72 hours after which the percentage mortality was calculated. All extracts tested were seen to possess moderate to good larvicidal effect against An. gambiae larvae in a concentration dependent manner with the highest mortality observed in O. gratissimum with 100%, Cy. citratus with 93%, Ca. papaya and V. amygdalina with 83%, T. catappa with 73% and the least being Ch. odorata with 63%at the end of the exposure period of 72 hours. These results showed that these plant extracts may be used as alternative insecticides against An. gambiae mosquitoes, with a further study on their phytochemicals, characterization and synergistic activities and their adaptability to field assay highly recommended.

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The JapanSociety of Medical Entomology and Zoology CJpn. Abstract: The effect of the source and size of bloodmeal on egg production in Culex quinguefasciatus was investigated. Three vertebrate hosts (man, rat and chicken) were used as sources of bloodmeal. Results show that the differences in the amount of blood engorged from the various hosts were not significant.However, the number of eggs produced by the mosquitoes fed on the blood of the various hosts varied significantly (p