Effects of clonazepam on developmental stages of Calliphora vicina Robineau-Desvoidy 1830 (Diptera: Calliphoridae) and its implications for PMI estimation.

Clonazepam (Rivotril®) is among the most widely prescribed benzodiazepines. However, its non-therapeutic use carries a substantial risk of misuse, dependence, and fatal overdose. The presence of such substances in tissues has the potential to complicate post-mortem interval (PMI) estimations in forensic entomology by altering insect growth rates. The present study investigated the effects of clonazepam on the developmental duration, larval weight and length of Calliphora vicina Robineau-Desvoidy 1830 (Diptera: Calliphoridae) under controlled laboratory conditions. Larvae were reared on bovine lung tissues treated with varying concentrations of clonazepam, and developmental duration, larval weight, and length were systematically recorded until adult emergence. The results demonstrated that Clonazepam exposure produced significant, concentration-dependent alterations in development. At the highest concentration tested, larval development was prolonged by 40 h, with a total developmental delay of up to 64 h compared with the control group. Furthermore, larval weight and length were significantly reduced, with developmental responses varying across larval, pupal, and post-feeding stages. Notably, this study reveals for the first time that clonazepam significantly delays the developmental stages of C. vicina. These findings underscore the necessity of correcting PMI estimates in cases of benzodiazepine intoxication, as ignoring this delay could lead to an underestimation of the time since death.