113 Natural parasitisation of castor lepidopteran pests by hymenopteran parasitoids T R Ranganath, B K Shivanna and Ramesh M Maradi Department of Agricultural Entomology, College of Agriculture, UAHS Shivamogga, Karnataka. India. Email: trranganath1@gmail.com Indian Journal of Plant Protection Vol. 48 No. 1&2, 2020 (113-116) Short Communication The magnitude of insect pest problem in castor is quite high in southern India where castor is grown mainly as rainfed crop, resulting in lower seed yield. The major pest problems in castor include the defoliators, semilooper, Achaea janata L.; tobacco caterpillar, Spodoptera litura Fab.; capsule borer, Conogethes punctiferalis Guenn. and the sucking pests, leafhopper, Empoasca flavescens Fab.; thrips, Retithrips syniacus Mayet and whitefly, Trialeurodes ricini Misra (Lakshminarayana and Raoof, 2005). Yield loss of 19 to 85 per cent has been reported in castor due to semiloopers and capsule borers (Singh et al., 1992). Indiscriminate use of pesticides leads to development of resistance in insects to insecticides, toxic effect on natural enemies, pest resurgence and pesticide residues on food and adverse effect on human beings and causes environmental pollution (Metcalf and Luckmann, 1982). These negative externalities, though cannot be eliminated altogether, their intensity can be minimized through development, dissemination and promotion of alternative technologies such as integrated pest management as well as good agronomic practices rather relying solely on chemical pesticides. Keeping all the above facts in view, a basic study was undertaken to know the extent of parasitization by natural enemies of castor lepidopteran pests, to enhance knowledge in biocontrol agents and to help efforts in biocontrol programmes. To study the incidence and parasitisation by various natural enemies on insect pests of castor during kharif 2018, the castor variety DCH-177 was sown in an area of 200m 2 with a row spacing of 90cm and 60cm between the plants and all other recommended agronomic practices were followed as per the package of practices (POP, 2008) at AHRS, Bhavikere. The possible number of eggs, larvae and pupae of pests were collected randomly from the field along with leaves at weekly intervals. The collected materials were placed in the cage/glass vials for the emergence of the adults and parasitoids. Data on total number of eggs, larvae and pupae and parasitized/emerged natural enemies were recorded daily. Thus, parasitisation was worked out. Later the collected specimens were identified by the experts at the institutes viz., UAS, GKVK, Bangalore and NRCB, Trichy. In the present study, efforts were made to find out natural enemies of major lepidopteran pests of castor viz., C. punctiferalis, A. janata and S. litura. Among these A. janata larvae were found parasitized by Microplitis maculipennis Szepligate and Euplectrus leucostomas Rohwer (Fig.1+2) and larval parasitoids viz., Eriborus sp. and an intermediate Ichneomonid (Fig. 3 unientified) on C. punctiferalis (Table1.) Per cent parasitisation is presented in the Table 2. Among the larval parasitoids, the braconid, M. maculipennis (Fig. 1) appeared to be promising parasitoid attacking A. janata. It was an internal and solitary larval parasitoid affecting third instar larvae. The parasitized larvae were seen in the field carrying at the posterior end a brown pupal cocoon of the parasitoid. The parasitized larvae do not feed and die of starvation and another gregarious and ecto-parasitoid, E. leucostomus (Fig. 2) was found to parasitise grown- up semilooper. Apart from these, some common predators like praying mantid and coccinellids were noticed during the study period. Parasitisation by M. maculipennis ranged from 4 to 8.33 per cent with an average of 5.85 per cent during study period, while peak parasitisation (8.33%) was recorded during 42 nd SMW, while parasitism of E. leucostomus ranged from 2.77 to 6.25 per cent with average of 1.67 per cent with parasitisation (6.25) during 44 th SMW. In case of castor capsule borer, Conogethis punctiferalis larval parasitism by Eriborus sp. varied from 5.00 to 8.33 per cent with an average of 3.55 per cent during study period with peak parasitization (8.33%) during 50 th SMW. Manjunatha et al. (2018) documented parasitism of M. maculipennis and E. leucostomus from September to December with peak incidence of 32.30% and 4.30 per cent, respectively. Rao et al.(2007) reported M. maculipennis as one of the important larval parasitoid of A. janata in castor cropping system, where they observed