Incidence of Bitter Gourd gall midge and assessment of Farmers management practices

Two gall midge species viz., Lasioptera falcata and L. bryoniae are found to infest the bitter gourd causing galls in shoots and leaf petiole arresting further growth of the plant. The infestation of the gall midge was high in Coimbatore (78.6%) and Tiruppur district (72.0%) as compared to other seven districts which showed an infestation of 15.3–18.0%. The natural enemies associated with the immature stages of gall midge are identified as Aprostocetus diplosidis, Bracon sp. and unidentified Platygastrinae. The natural parasitization of gall midge was also high in Coimbatore (43.5%) and Tiruppur (39.6%) districts of Tamil Nadu. The farmers growing bitter gourd ranked gall midge pest as second next to fruit fly and are using more than nine insecticides for controlling the pest including one combination insecticide and two synthetic pyrethroids. The other insecticides used belong to organophosphate, neonicotinoid and pyridincarboxamide groups.