Thermal Regimes, Age and Sex Modulate Feeding Attributes of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae)

Feeding attributes of phytophagous insects are greatly influenced by abiotic and biotic factors. Therefore, we assessed the combined effect of temperature, age and sex on food consumption and utilization efficiencies of Zygogramma bicolorata Pallister. This Mexican beetle is known as one of the most promising candidates for the biocontrol of Parthenium hysterophorus Linnaeus, a noxious weed of barren, grazing and farming lands. Temperature, age and sex influenced food consumption, its utilization and ecological efficiencies of the beetle. Temperature between 27°C and 30°C was found optimal for 20-day-old adults of Z. bicolorata to convert and utilize the food biomass to body mass. Above and below the optimal temperature and age, the feeding attributes declined. Young females kept at 27°C consumed more food and laid more number of eggs compared to other females at different temperatures. This study reveals that females are more voracious feeders than the males regardless of temperature regimes. The present findings can be helpful to mass-multiply Z. bicolorata in the laboratory for the biocontrol of Parthenium weed in fields and agricultural farms. The results also suggest that global climate change may affect the biocontrol potential of the insect, but field investigations are needed to support the present findings.