LIFE TABLE OF THE PARTHENIUM BEETLE, ZYGOGRAMMA-BICOLORATA PALLISTER (COLEOPTERA, CHRYSOMELIDAE) IN BANGALORE, INDIA

Time-specific life tables were constructed for the Mexican beetle, Zyg ogramma bicolorata Pallister (Coleoptera: Chrysomelidae), which is a p romising biological control agent of the Neotropical weed, Parthenium hysterophorus L. (Asteraceae) in and around Bangalore, India. Infertil ity of eggs (46.00-71.10%) was found to be the key mortality factor, f ollowed by death during the pupal stage (15.76-21.38%), as confirmed b y key mortality factor analysis and construction of survivorship curve s. No parasitoids or predators were recorded on this insect, while som e of the dead pupae/pre-pupae (2.27-17.24%) were found to be infected by Metarhizium anisopliae (Metchnikoff) Sorokin. The high generation t rend values (305.88-557.14), give an indication of the biotic potentia l of this insect, which was found to cause rapid defoliation of the we ed under field conditions.