Effects of Herbicide Glyphosate on Fitness Attributes of <i>Zygogramma bicolorata</i> Pallister

Abstract

In this study, the effects of glyphosate on the biology and fitness of the biocontrol agent Zygogramma bicolorata against parthenium weed. Bioassay of glyphosate was conducted using a minimum range of the field-recommended dose (0.408%). Results showed that indirect exposure to glyphosate caused significant mortality of I, II, III, and IV instar Z. bicolorata grubs. The highest mortality (23.60%) was recorded in the first instar. Furthermore, the total larval developmental period was significantly prolonged in the group exposed to glyphosate (19.50 days) compared to the unexposed group (17.73 days). The application of glyphosate also caused a variation in pupation period. In addition, the longevity of both male and female Z. bicolorata was negatively impacted by glyphosate treatment. Overall, these findings suggest that glyphosate has an ecotoxic effect on Z. bicolorata and may have significant implications for its use as a biocontrol agent for parthenium. It is important to carefully consider the potential risks associated with the use of herbicides and ensure that they are used in a safe and responsible manner to minimize any negative impacts on non-target organisms.