Effective integrated pest management (IPM) of the melon fly Zeugodacus cucurbitae (Coquillett), a devastating pest threatening horticultural production in Africa, is urgently needed. In this study, a caged field experiment was implemented in Thika, Kenya to test the efficacy of Metarhizium anisopliae (Mechnikov) Sorokin ICIPE 69 for Z. cucurbitae control in courgette Cucurbita pepo L. Treatments included: (1) dry conidia of M. anisopliae ICIPE 69 applied in an autodissemination device (fungus); (2) dry conidia of M. anisopliae ICIPE 69 in an autodissemination device combined with cuelure, a male attractant (fungus + cuelure); (3) a commercial insecticide (profenofos + cypermethrin) (insecticide); and (4) an untreated control (control). Each treatment was replicated thrice and the experiment was conducted twice during two seasons. Flies (300/tunnel) and treatments were introduced at flowering. One day later, 25 flies/tunnel were randomly collected from each cage to assess conidial acquisition (for fungus and fungus + cuelure treatments only) and mortality during a 10‐day interval in the laboratory. Flies in the fungus + cuelure treatment acquired more conidia (18.02 ± 0.48 conidia/fly) than those in the fungus treatment (11.93 ± 0.40 conidia/fly). Flies in the fungus + cuelure treatment experienced the highest mortality (95.31% ± 1.69%), while those in the insecticide treatment experienced the lowest (38.70% ± 4.32%). Dry conidia were collected from the autodissemination devices (in the fungus and fungus + cuelure treatment) daily for 7 days after flowering to check for compatibility through germination tests. Percentage germination reduced over time from 86.45% ± 1.77% and 87.72% ± 1.71% on day 1 to 16.39% ± 2.11% and 42.76% ± 1.74% on day 7 (seasons 1 and 2, respectively). The yield was significantly different among treatments and was, across seasons, highest in the fungus + cuelure (6961 ± 550 kg/ha) and insecticide (7267 ± 352 kg/ha) treatments and lowest in the control treatment (2089 ± 155 kg/ha).