Biological attributes, predatory potential and functional response of syrphid, <i>Episyrphus viridaureus</i> (Weidemann) on potato aphid, <i>Macrosiphum euphorbiae</i> (Thomas) infesting tomato

<i>Macrosiphum euphorbiae</i> (Thomas) (Hemiptera: Aphididae), commonly known as potato aphid, is an economically damaging pest in tomato agroecosystem. Farmers often resort to chemical insecticides for its control, but this approach poses long-term ecological challenges. Biological control, which involves the strategic use of natural enemies, offers a more sustainable and effective alternative for managing insects. The syrphid, <i>Episyrphus viridaureus</i> (Weidemann) (Diptera: Syrphidae) is a natural predator of potato aphid within tomato fields. However, comprehensive information on its developmental biology, population growth parameters, predatory potential and functional response remain limited, prompting this study. In the present study, <i>E. viridaureus</i> was able to complete its lifecycle successfully while feeding on <i>M. euphorbiae</i> with an intrinsic rate of increase (<i>r</i>) (offspring/individual/day) of 0.103 and finite rate of increase (λ) (offspring/day) of 1.108. The larvae of <i>E. viridaureus</i> consumed 332.35 aphids out of which third instar larvae made the maximum contribution by consuming 232.69 aphids. All the three larval instars exhibited a type-II functional response against different densities of <i>M. euphorbiae</i>. Functional response parameters like attack rate (a) increased and handling time (<i>T</i>_h) decreased as the larval stages advanced. This research highlights the potential of <i>E. viridaureus</i> as an effective biocontrol agent against <i>M. euphorbiae</i>, contributing to sustainable pest management.