Determination of Key Mortality Factor of Mexican Beetle, <I>Zygogramma Bicolorata</I> Pallister

R. Bhoopathi; Sudhida Gautam; R. D. Gautam; Subhash Chander

doi:10.18311/jbc/2011/3743

Jump To References Section

Authors

R. Bhoopathi
Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012 ,IN
Sudhida Gautam
Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012 ,IN
R. D. Gautam
Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012 ,IN
Subhash Chander
Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012 ,IN

DOI:

https://doi.org/10.18311/jbc/2011/3743

Keywords:

Life Table, Zygogramma Bicolorata, Parthenium hysterophorus.

Abstract

Life tables were constructed under Delhi conditions for Zygogramma bicolorata in order to determine the key mortality factor acting on the species. The pupal stage was found to be the key mortality stage that contributed most to the overall mortality followed by egg stage. Pupal malformation, failure to lay eggs and infertility were prominent mortality factors. The main cause of mortality of older larvae was their inability to burrow into hard and dry soil for pupation. Besides, weather factors in general were found to have an effect on all developmental stages of Z. bicolorata. The sex ratio was biased towards females with their proportion being 0.6-0.7. The generation trend index was very high (272.21) during July followed by October (231.07) and August (199.40). The generation mortality was low during June-October while it was high during January, May and December.