Even in organically managed potato fields, Leptinotarsa decemlineata is frequently controlled using chemical pesticides. Mulching presents a promising alternative for suppressing egg deposition and larval populations of L. decemlineata. We evaluated its effects through three field trials, each replicated four times, comparing unmulched control plots (a) with plots mulched using grass-clover (b) or triticale-vetch (c). In 2020 and 2021, larvae and their developmental stages were monitored twice weekly on 30 marked potato plants per plot, whereas in 2022, observations occurred three times over the season on 16 plants per plot. To investigate potential microclimatic changes induced by mulching, temperature loggers were positioned 15 cm above the canopy and underground. Across all mulched treatments, larval numbers were reduced on average by 65%, and advanced larval stages appeared later and in smaller numbers than in unmulched plots. In 2022, the emergence of a second-generation adult population of L. decemlineata was observed, with densities in mulched plots reduced by approximately 90%. During warm and hot conditions, canopy temperatures in mulched plots were substantially higher than in unmulched plots, often exceeding the optimal range for L. decemlineata development. Overall, mulching appears to delay or decrease adult beetle immigration and may slow egg and larval development
