Tropicultura (Jan 2005)
Préférences alimentaires de Sahlbergella singularis Hagl. (Hemiptera: Miridae) vis-à-vis de quelques clones de cacaoyers (Theobroma cacao L.)
Abstract
Feeding Preferences of Sahlbergella singularis Hagl. (Hemiptera: Miridae) to some Cocoa (Theobroma cacao L.) Clones. The selection of cocoa clones, resistant to Sahlbergella singularis Hagl. was done in the laboratory according to the standardized method of indoor microtests based on the study of mirid feeding preferences. Fourteen cocoa clones were involved. The Sca6 clone was the control. An index (i) which expresses the ratio of the number of stings on the clone to that obtained on the control was calculated for each cultivar. Which has enabled to quantify the levels of attractiveness of cocoa clones to S. singularis and to classify these clones in three groups: less attractive clones (i< 1), non different (i= 1) and more attractive (i> 1). The results obtained showed that the mean numbers of feeding stings on the control (tr) ranged from 5.49 to 5.62 (5.49≤ tr≤ 5.62) and that obtained on the other clones (tc) from 5.29 to 6.18 (5.29≤ tc ≤ 6.18). The Na33 clone had the highest stings mean number (6.18) and IFC 100 the lowest one (5.29). The High Amazonian clone Na33 was the most attractive and the clones ICS100, IFC100, (exotic trinitario), Sca12 (catongo) and Na32 (High Amazonian) were less attractive. On the other hand the clones IFC1363, IFC1362, IFC1374 (catongo), UPA337, T60/887, ICS1 and IMC60 (High Amazonians) and ICS95 (exotic trinitario) were non different. The reactivity seemed not depending on the origin of the clone. Save the High Amazonian clone Na33 which was the most attractive there were among non different and less attractive clones as well exotic trinitario, catongo as High Amazonians.
