Lethal and Sub-lethal effects of insecticides on the biological attributes of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae): a biocontrol agent of Parthenium hysterophorus L.
Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae) is an exotic and the most important biocontrol agent of Parthenium hysterophorus L. (Asteraceae). It was first introduced to Australia from Mexico in 1980 and subsequently to India in 1983. It became abundant within 3 years of introduction, resulting in a significant reduction in parthenium density in local areas. Further, biocontrol programs were initiated in Jammu and Kashmir in 1989, and large-scale releases were made in 1992. Neonates feed voraciously on young leaves and undergo four molts and completed development within 11–13 days. Fullygrown larvae burrow into the soil to pupate; the pupal period lasts for 2 weeks. Life cycle is completed in 23–30 days with four generations/ year, depending on rainfall and food availability. Zygogramma bicolorata have shown its biocontrol potential in different parts of the country ranging fromnegligible to excellent under different field conditions. Despite of its tremendous importance, efforts have been made to study the effect of insecticides on survivorship, mortality, fecundity, and life indices, so that, population trend may be ascertained. Literature is not available on the effects of insecticides on the life table parameters and development of Z. bicolorata that decreased its performance on parthenium, so that, we can minimize the load of synthetic chemicals upon this biocontrol agent of parthenium as well as increasing the economy of growers and saving the environment for future generation of human being and his environment.
Fazil Hasan and M. Shafiq Ansari (2017). Neotropical Entomology, DOI 10.1007/s13744-017-0485-3