IN VITRO SCREENING OF INSECTICIDAL EFFECT OF PLANT AQUEOUS EXTRACTS ON THE COWPEA APHID APHIS CRACCIVORA
2018; Volume: 2; Issue: 2 Linguagem: Inglês
10.7251/agreng1702075l
ISSN2490-3442
AutoresSalim Lebbal, Aissa LEBBAL, Azzeddine Zeraib,
Tópico(s)Insect and Pesticide Research
ResumoThe research of new control methods that have low negative effects represent analternative aiming to limit disadvantages of chemical control of pests. This studyaimed to test the effect of 11 aqueous plant extracts belonging to four species(Santolina africana, Juniperus thurifera, Artemisia herba-alba and Pituranthosscoparius), on the larvae of the aphid Aphis craccivora installed on the leaves ofRobinia pseudoacacia under laboratory conditions. The insecticidal effect ofaqueous extracts on the mortality of aphids was evaluated by the introduction ofacacia leaflet into an extract and infestation of them by 10 larvae of the aphid.Later, a counting of dead larvae after 3, 6, 12 and 24 h was performed. In addition,we investigated the effect of the aqueous extracts on the orientation of the aphidsby putting the latter in a position of choice between six leaflets, each treated with adifferent extract. In addition, a phytochemical screening was carried out to detectthe presence of saponins and polyphenols in the extracts studied. Through ourstudy, the extract obtained from S. africana at a concentration of 15% was the mosteffective with a mortality rate higher than 80% after 24 h of artificial infestation.As for the effect of the four extracts on the orientation of the cowpea aphid, theydid not attract the larvae massively. Regarding phytochemical screening,differences in the chemical composition of the analyzed extracts were observed.These differences may explain in part the variation of aphicidal effects of testedplant extracts.
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