R. S. Bal ¹, Z. S. Dhaliwal ¹, S. S. Bains ¹

Affiliations
1 Department of Entomology, Punjab Agricultural University, Ludhiana - 141 004, IN

Abstract

Observations on the survival, development and reproduction of Pyrilla perpusilla (Walker) and its ectoparasitoid, Epiricania melanoleuca (Fletcher) were recorded in the laboratory to determine the comparative rates of population growth in these species. The finite rate of increase (λ) was higher (8.984/♀/month) in the parasitoid than that of the host (4.7111/♀/month). Host specificity and inadequate availability of the proper host stage for the randomly searching parasitoid larvae were found to be limiting for the rapid multiplication of the latter under field conditions. In view of the above limitations of E. melanoleuca, a control strategy against pyrilla has been suggested.

Keywords

Pyrilla perpusilla, Epiricania melanoleuca, Rate of Increase.

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R. S. Bal ¹, Z. S. Dhaliwal ¹, S. S. Bains ¹

Affiliations
1 Department of Entomology, Punjab Agricultural University, Ludhiana 141 004, IN

Abstract

Biological effects or parasitism by Epiricania melanoleuca (Fletcher) on the nymphal and adult stages of Pyrilla perpusilla (Walker) have been investigated under laboratory conditions. Parasitoid-Infected Injuries caused high mortality (95.9%) In the first Instar nymphs within two days of parasitisation. Appreciable nymphal mortality (70%) also occurred in the parasitised second, third, fourth and fifth Instars In the Iorm of weak nymphs, nymphal-adult Intermediates and weak adults though after a prolonged nymphal duration In the later three stars. Fecundity or the parasitised adults was reduced by 22 per cent but their longevity was enhanced significantly.

Keywords

Epiricania melanoleuca, Pyrilla perpusilla, Biological Effects, Parasitism.

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