Seasonal abundance of predatory bugs, Eocanthecona furcellata (Wolff.) and Rhynocoris fuscipes (F.) and its olfactory responses towards plant andpest mediated semiochemical cues in Pigeonpea ecosystem

Abstract

Studies on seasonal abundance of the predatory bugs, Eocanthecona furcellata (Wolff.) and Rhynocoris fuscipes (F.) on short duration pigeonpea variety Manak during 2012-14 revealed that the incidence of both the heteropteran bugs commenced from the 36th meteorological standard week and persisted up to 47th meteorological standard week of both the years. These bugs were found predating on larvae of spotted pod borer, Maruca vitrata (Geyer), one of the major insect pests of pigeonpea. Correlation studies with different weather variables indicated that the populations build up of these bugs exhibited a significant positive correlation with maximum temperature, minimum relative humidity and rainfall. In order to identify the semiochemical cues mediating the host seeking behavior of these predatory bugs towards M. vitrata, a laboratory experiment was conducted using four-arm olfactometer. The predatory bugs displayed a much higher preference for volatiles produced by M. vitrata infested pigeonpea flowers and early instar larvae of M. vitrata.