Effects of conspecific semiochemical footprints on feeding attributes and development of Mexican beetle, Zygogramma bicolorata Pallister.
Parthenium hysterophorus is a toxic weed of agricultural farms and causes asthma, hay fever and allergies in humans. Amongst the known insect species for weed biocontrol, the Mexican beetle, Zygogramma bicolorata Pallister is the only cost effective biocontrol agent that suppresses the growth of the weed. In the present study, feeding attributes and development of immature stages of Z. bicolorata have been assessed in presence of conspecific semiochemical tracks of other co-existing members. Results revealed that the presence of conspecific semiochemical tracks on P. hysterophorus diminished the feeding attributes of Z. bicolorata larvae on the weed. Amongst all the larval instars, the fourth instars displayed the highest consumption rates and conversion efficiencies. Present findings therefore suggest that the presence of conspecific semiochemicals on P. hysterophorus impedes augmentative biological control of the weed by the larvae of Z. bicolorata. However, field based studies are still needed to validate the present findings.