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Subject: Entomology × Author: Augustine, Neethu Maria × Start date: 1968 × Thesis Type: M.Sc ×
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    Management of Pyrilla perpusilla (Walker) with ecto-parasitoid, Fulgoraecia melanoleuca (Fletcher) on sugarcane
    (Punjab Agricultural University, 2022) Augustine, Neethu Maria; Shera, P S
    The studies on “Management of Pyrilla perpusilla (Walker) with ecto-parasitoid, Fulgoraecia melanoleuca (Fletcher) on sugarcane” were conducted at the Punjab Agricultural University (PAU), Ludhiana during 2021-2022. The releases of F. melanoleuca cocoons (2000, 4000 and 6000 cocoons ha-1) and eggs (2, 4 and 6 lakh eggs ha-1) were compared with chemical control (chlorpyriphos 20 EC @ 1500 ml ha-1) and untreated control. The overall number of pyrilla nymphs and adults was significantly reduced after two releases of parasitoid eggs and cocoons. The reduction of pyrilla population creased progressively either with increase in number of released cocoons (2000, 4000 and 6000 ha-1) or with released eggs (2, 4 and 6 lakh ha-1). The nymphal and adult parasitism also increased with increase in doses and time and it was significantly higher when parasitoids were released at higher doses, i.e. 6 lakh eggs ha-1 (53.75 %) and 6000 cocoons ha-1 (50.60 %) as compared to lower ones. The augmentative releases of parasitoid eggs and cocoons plays a noteworthy role in increasing the parasitoid count (egg masses, cocoons and adults) in the released plots with time. However, chlorpyriphos 20 EC was found to be highly detrimental to the parasitoid as no parasitism and population count was observed in insecticide sprayed plots. Overall, two releases of F. melanoleuca eggs (6 lakh ha-1) or cocoons (6000 cocoons ha-1) at monthly interval (1st week of August and 1st week of September) proved better with respect to reduction in pyrilla population, increase in parasitoid population and parasitism rate and also rendered higher cane yield and better juice quality. The storage of F. melanoleuca eggs and cocoons at different temperatures (0, 5, 10 and 150C) for various durations (1, 2, 3, 4, 5 and 6 weeks) was compared with ideal temperature (270C) for the overall fitness of the parasitoid. The cocoons of F. melanoleuca can be stored at 100C for 1 week and at 150C for 1-2 weeks as these temperature regimes and storage time exhibited negligible negative effect on developmental and reproductive parameters of the parasitoid. Similarly, eggs can be stored at 150C for 1week without much negative effect on hatchability and incubation period of the parasitoid.