2016, Vol. 4, Issue 6, Part D

author(s)
Nosiba S Hamid, Mutaman A Kahil and Nasir A Ibrahim

abstract
Natural products have come from various sources like terrestrial plants, terrestrial microorganism, marine organisms, terrestrial vertebrates and invertebrates. The study was aimed to examine the effects of ethanol extracts of fruit pulp and seeds of bitter apple Citrullus colocynthis against the 3^rd and early 4^th instar of Anopheles arabiensis and Culex quinquefasciatus larvae. A set of 20 larvae of each species were added by means of dropper to a set of 250 ml test cups each containing 250 ml tap water. The ethanol extracts of C. colocynthis fruit pulp and seeds were tested at concentrations of 87.13, 69.74, 52.26, 34.87 and 17.39 ppm. The exposure period was 24 hour. Results revealed that, the ethanol extracts of fruit pulp and seeds illustrated considerable mortality in A. arabiensis and C. quinquefasciatus. The percentages mortality in A. arabiensis larvae treated with ethanol extracts of C. colocynthis fruit pulp ranged between 90% and 45%, and when they were treated with seed extract, mortalities ranged between 85% and 35%. Likewise, the percentages mortality in C. quinquefasciatus larvae after 24 hours, against ethanol extract of fruit pulp ranged between 90% and 45% and when they were treated with the ethanol extract of seed showed a ranged of 90% and 30%. The toxicity values of LC₅₀ which were LC₅₀ values of the ethanolic, extracts of C. colocynthis fruit pulp and seeds were 50.11, 30.90, 25.12, and 39.81 ppm, respectively. In conclusion, In conclusion, this study found that, the ethanol extract of C. colocynthis seeds showed relatively higher larvicidal potentiality against C. quinquefasciatus larvae more than A. arabiensis larvae. The ethanol extract of C. colocynthis fruit pulp showed relatively higher larvicidal potentiality against A. arabiensis larvae more than C. quinquefasciatus larvae (not like the seed extract), also, the seed extract was more potent than the fruit pulp extract by more than two folds against both larvae. This, in turn, could provide a decision for making a recommendation to use C. colocynthis as a safe insecticide alternative for controlling mosquito species.