Year 2017, Volume 2, Issue 2

Year : 2017
Volume : 2
Issue : 2
   
Authors : Salim LEBBAL, Aissa LEBBAL, Azzeddine ZERAIB
Title : IN VITRO SCREENING OF INSECTICIDAL EFFECT OF PLANT AQUEOUS EXTRACTS ON THE COWPEA APHID APHIS CRACCIVORA
Abstract : The research of new control methods that have low negative effects represent an alternative aiming to limit disadvantages of chemical control of pests. This study aimed to test the effect of 11 aqueous plant extracts belonging to four species (Santolina africana, Juniperus thurifera, Artemisia herba-alba and Pituranthos scoparius), on the larvae of the aphid Aphis craccivora installed on the leaves of Robinia pseudoacacia under laboratory conditions. The insecticidal effect of aqueous extracts on the mortality of aphids was evaluated by the introduction of acacia 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 aphids by putting the latter in a position of choice between six leaflets, each treated with a different extract. In addition, a phytochemical screening was carried out to detect the presence of saponins and polyphenols in the extracts studied. Through our study, the extract obtained from S. africana at a concentration of 15% was the most effective 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, they did 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 tested plant extracts.
For citation : Lebbal, S., Lebbal, A., Zeraib, A. (2017). In vitro screening of insecticidal effect of plant aqueous extracts on the cowpea aphid Aphis craccivora. AGROFOR International Journal, Volume 2. Issue No. 2. pp. 75-81. DOI: 10.7251/AGRENG1702075L
Keywords : Santolina africana, orientation, mortality rate, polyphenols, saponins
   
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