AN EVALUATION OF THE LARVICIDAL EFFICACY OF THE SEED OIL EXTRACTS OF SELECTED PLANTS AGAINST SOME MOSQUITO SPECIES.
AN EVALUATION OF THE LARVICIDAL EFFICACY OF THE SEED OIL EXTRACTS OF SELECTED PLANTS AGAINST SOME MOSQUITO SPECIES.
No Thumbnail Available
Date
2015-05
Authors
KAMBA, Bayo.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The evaluation of the larvicidal potency of the plant seeds might lead to the development of safe and environmentally friendly insecticides. The oils of the seeds of Adansoniadigitata, Parkiabiglobosaand Perseaamericanawereevaluated for their chemical composition and theability to kill mosquito larvae of Aedesaegypti, Aedesvittatusand Culexquinquefasciatus under laboratory and outdoor conditions.The seeds of the three plants were extracted from 100g powdered kernel with 300mL petroleum ether using soxhlet extractor for 5-6hr. The solvent was evaporated under vacuum leaving behind oil seed.The extracted oils were quantified gravimetricallyto determine the presence of chemical constituents of larvicidal importance.Bioassay oflate third larval instar was tested using six concentrations of 0.01, 0.02, 0.04, 0.08, 0.16 and 0.32mL ofeach seed oil extract making up to 100mL with distilled water. A batch of 25 mosquito larvae were tested in three replicates for each concentration along with the respective control of distill water devoidof extracts. The chemical composition of the seed oil extracts revealed the presence of acid, free fatty acid, iodine, peroxide and saponification values in different quantities. Acid and free fatty acidvalues did not differ significantly (p>0.05) between the extracts of A. digitata (5.04 and 2.50mgKOH/g) and P. biglobosa(5.05 and 2.50mgKOH/g) except forP. ameriacana (19.63 and 9.90mgKOH/g) (p<0.05) where significance was recorded. Iodine and peroxide differ significantly (p<0.05) across all the three seed oil extracts. Saponins was very high in all the seed oil extracts compared to other phytochemical compositions (acid, free fatty and peroxide values), but was only significant (p<0.05)in P. americana (199.33mL/Kg). The cidal effect of the seed oil extracts was dose-dependent for A. digitata, P. americana and
ix
P. biglobosa. The median lethal concentration (LC50)valuesof Adansoniadigitata seed oiltested against three mosquito species for laboratory and outdoor conditions were respectivelyfound to be as follows:Ae. aegypti0.1179mL/L and 0.4886mL/L;Ae. vittatus0.0998mL/L and 0.00055mL/L; and Cx. quinquefasciatus0.0519mL/L and 0.00397mL/L.For Parkiabiglobosa, theLC50values determined for Ae. aegyptiwere 0.1084mL/L and 0.3327mL/L;Ae. vittatus, 0.1891ml/L and 0.0010ml/L; and Cx. quinquefasciatus 0.1058mL/L and 0.0134mL/L for laboratory and outdoor conditions respectively. Perseaamericanahad the following LC50 values: Ae. aegypti 0.3026mL/L and 0.0561mL/L;Ae. vittatus0.1118mL/L and 7.0x10-6mL/L and Cx. quinquefasciatus 0.0858mL/L and 0.1862mL/L for laboratory and outdoor conditions,repectively.These results suggest that the seed oilsof A. digitata, P. biglobosaand P. americanacan be harnessed for the development of bio-larvicide for the control of the mosquitoesspecies studied and invariably the diseases they transmit.
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF A MASTERS DEGREE IN ZOOLOGY.
Keywords
AN EVALUATION,, LARVICIDAL,, EFFICACY,, THE SEED OIL,, EXTRACTS,, SELECTED,, PLANTS,, AGAINST,, SOME,, MOSQUITO,, SPECIES.