This study investigates the toxicity of the fungicide mancozeb on predatory bug Rhynocoris fuscipes. Female R. fuscipes were collected from groundnut plants in Peppeganj and reared in the laboratory for mancozeb exposure experiments. The bugs were subjected to the field- recommended concentration of mancozeb at varying frequencies (one dip, weekly dip, daily dip, and no dip) to assess mortality rates, developmental duration, and prey consumption. Exposure to mancozeb resulted in either an increase (14.3 ± 0.5 days) or decrease (4.3 ± 0.5 days) in nymphal duration, a reduction in prey consumption capacity (2 ± 0), and elevated mortality rates (60%, 66.66%, 100%) at third, fourth, and fifth nymphal stages in the daily dip (DD) category. Additionally, mancozeb significantly impacted prey consumption capacity (5.8±0.6, 5.9±0.3), developmental duration (48.8±0.2, 46.9±0.2 days), and mortality percentages (30.2%, 40%, and 16.66%, 33.33%) at third and fourth nymphal stages in the weekly dip(WD), and one dip (OD) categories respectively.