• S S Prasad

      Articles written in Proceedings – Animal Sciences

    • The effect of topical and oral administration of a juvenoid to the last instar larva ofSpodoptera litura Fabr.

      U S Srivastava S S Prasad

      More Details Abstract Fulltext PDF

      The effect of administering different quantities of a JHA topically and orally to the last instar larva ofSpodoptera litura of different ages has been studied. With both modes of treatment the effects comprised prolongation of the life of the instar followed frequently by death; imperfect ecdysis adversely affecting survival; production of non-viable larval-pupal intermediates, and occurrence of extra larval moults. Topical treatment is more effective but ecdysial failure and production of 1-p intermediates are more frequent with oral administration. A single supernumerary larval moult may be caused by administering a large quantity of JHA to 1 day old larva. Supernumerary instars are non-viable. Contrary to expectation, 1-p intermediates produced by early treatment show more pupal characters whereas middle-aged larvae show more larval characters. Prolongation of larval life caused by small quantities of JHA is the largest single effect which results into larval mortality.

    • A study of pupal-adult intermediates produced with juvenoid treatment ofSpodoptera litura Fabr. pupae

      U S Srivastava S S Prasad

      More Details Abstract Fulltext PDF

      Pupae ofSpodoptera litura were treated topically with a juvenoid, 6, 7-epoxy-3-ethyl-1 (p-ethyl phenoxy)-7 methylnonane. The effects comprised death, production of pupal-adult intermediates of varying grades and adultoids. The production of pupal-adult intermediates was studied in relation to age of the pupa at the time of treatment and the dose of the compound administered. It was found that up to the age of 20 hr the degree of morphogenetic response was directly correlated with the dose of the compound administered and inversely with age, but after this age, an increase in the quantity of the hormone, beyond the effective dose did not further augment the effect.

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