Incidence of Groundnut Leafminer (GLM), Aproaerema modicella (Deventer) (Lepidoptera: Gelechiidae) and its Parasitic Fauna on Alternate Leguminous Hosts in Tamil Nadu, India

Abstract

Background: The groundnut leafminer (GLM), Aproaerema modicella is an important pest of several legume crops which causes 50 to 100 per cent yield loss in India. The exploration of indigenous natural enemies is crucial to the success of every biological control strategy. Besides, alternative host plants act as a source of both herbivorous pests and their natural enemies. In this view, occurrence of GLM and their parasitic fauna on groundnut, alternate leguminous hosts viz., redgram and babchi were recorded. Methods: Survey on damage potential of GLM and their parasitic fauna were recorded on groundnut at Sivagangai and Coimbatore districts of Tamil Nadu, India during 2016 to 2018. Survey was also conducted to find the damage potential of A. modicella on alternate leguminous hosts viz., redgram, babchi and their parasitic fauna at Coimbatore district. The damage potential of A. modicella, per cent parasitization and parasitoid emergence were assessed from A. modicella infested groundnut, redgram and babchi leaves. Result: Severe incidence of A. modicella was recorded as 98.10% (2016 to 2017) and 98.45% (2017 to 2018) at Sivagangai district. The parasitization of GLM was also found higher at Sivagangai recording 46.67% in both the years which was positively related with the pest population. 13 hymenopteran parasitoids belonging to eight families were recorded. Among them, Avga choaspes Nixon recorded high per cent parasitoid emergence (20.00%). Furthermore, GLM incidence on redgram and babchi indicated the highest damage potential of 38.20 and 34.50 per cent and parasitization of 33.33 and 20.00 per cent, respectively during 2017 to 2018.