Host-parasitoid relationship between Pyrilla perpusilla (Walker) and Fulgoraecia melanoleuca (Fletcher) on sugarcane
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Date
2021
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Punjab Agricultural University, Ludhiana
Abstract
The studies on the “Host-parasitoid relationship between Pyrilla perpusilla (Walker) and
Fulgoraecia melanoleuca (Fletcher) on sugarcane” were conducted at the Punjab Agricultural
University, Ludhiana during 2019 and 2020. Among the host stages, 4th instar nymphs and
adult females were more suitable for the parasitoid, F. melanoleuca in terms of higher larval
survival, adult emergence, more proportion of females in the progeny and higher fecundity.
The exposure of 1st instar host nymphs to the parasitoid resulted in cent per cent mortality
within two days before any signs of parasitism. None of the parasitized 2nd to 4th instar nymphs
survived as normal adults as all the parasitized individuals died as nymphs, nymph-adult
intermediates or weak adults. However, in case of parasitized 5th instar nymphs, 18.0 per cent
adults were normal. The mean longevity of nymphs parasitized in the 3rd, 4th and 5th instars was
prolonged significantly; maximum prolongation was in the 4th instar. However, longevity of
nymphs parasitized in the 2nd instar was even less than un-parasitized ones. When host adults
were offered to the parasitoid, there were significant differences in mortality of parasitized and
un-parasitized adults. Further, parasitoid-induced prolongation in the longevity of the surviving
parasitized adults was observed for both the sexes. Among different agro-climatic zones,
population count of P. perpusilla and F. melanoleuca as well as natural parasitism was more in
Jalandhar (central plain zone) as compared to Hoshiarpur (sub-mountainous undulating zone)
and Fazilka (Western zone). The parasitoid remained active in overlapping stages during the
months of April to November with peak activity in September month at all the locations. It
overwintered in cocoon or egg stage on sugarcane trash from December to March months.
Among the selected insecticides, chlorpyriphos 20 EC, imidacloprid 17.8 SL and fipronil 5 SC
were comparatively toxic to the parasitoid, while pymetrozine 50 WG, chlorantraniliprole 18.5
SC, flubendiamide 480 SC and flonicamid 50 WG were harmless to moderately harmful. The
prolonged pupal period, reduction in adult emergence and decreased adult longevity were the
sub-lethal effects in the insecticides, chlorpyriphos 20 EC, imidacloprid 17.8 SL and fipronil 5
SC. Biopesticides (Bacillus thuringiensis var. kurstaki 0.5 WP, Metarhizium anisopliae 1.0 WP
and Beauveria bassiana 1.0 WP) and botanicals (azadirachtin 1500 and 50000 ppm) were safer
to all the stages of F. melanoleuca.
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Citation
Sharma,Tarun (2021). Host-parasitoid relationship between Pyrilla perpusilla (Walker) and Fulgoraecia melanoleuca (Fletcher) on sugarcane (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.