Efficacité de la coccinelle aphidiphage Semiadalia undecimnotata Schn. en serre

Abstract

RÉSUMÉLast-instar larvae of Semiadatia undecimnotata were used in inundative releases against eggplant aphids in the glasshouse. The number of larvae placed on each plant was determined according to the feeding rate of this instar and the total biomass of aphids. In most cases, these biological treatments induced a very appreciable decrease of aphid populations. In spite of these hopeful results, the method seems difficult to apply in large glasshouses. The main reasons for this are : the reproductive potential of the aphids, the need for a large number of larvae, the necessity for a minimum prey density in order to maintain the larvae on the plant, their prefered localization on the middle level of the eggplants, and the larval and adult mobility which results in a wastage of the biological agent. The problems which the adult mobility of this predator presents for its acclimatization in glasshouses through the crop growing period can perhaps be resolved by searching for better adapted exotic species or by selecting for less mobile strains.

Intra- and inter-specific interactions between <i>Coccinella transversalis</i> and <i>Cheilomenes sexmaculata</i> in relation to prey abundance

“…Here, the fourth instar showed better predation activity than the third larval instar and the adult consumed more aphids as compared to the 3 rd and 4 th instar grubs. Possibly because they have higher energy requirements (Ahlawat et al, 2008;Mishra et al, 2012) and store energy for future development and metamorphosis (Ferran & Larroque, 1977). Earlier studies reported that older instar required more food than the previous instar due to bigger size, longer duration and accumulated nutrients for the pupal period (Pandi et al, 2012;Işikber, 2005;Prabhakar & Roy, 2010).…”