Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

The impact of levocetirizine dihydrochloride on the development cycle of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae)

Entomotoxicology studies the relationship between toxins and arthropods. In forensic investigations, the postmortem interval (PMI) can be estimated by analyzing necrophagous arthropods and comparing their development stages to known life cycle data. However, drugs present in the deceased’s system can alter the development cycle of these insects, potentially leading to inaccurate PMI estimations. This study examined the effect of the antihistamine levocetirizine dihydrochloride on the development cycle of the common necrophagous fly Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). Two groups of C. vicina were observed under controlled conditions in triplicate containers containing minced beef liver. The control group was placed on plain liver, while the experimental group was placed on liver inoculated with a scaled overdose of levocetirizine dihydrochloride. Throughout the development cycle, fifty larvae from each container were weighed at each developmental stage. After comparing the mass trends, it was found that the development cycle of the drug-exposed group proceeded approximately 1.5 days faster than the control group. These results indicate that levocetirizine dihydrochloride accelerates the lifecycle of C. vicina. If this effect is not considered, PMI could be overestimated, making the time since death appear longer than it actually is. By identifying the presence of this antihistamine and applying the findings of this study, forensic investigators can improve the accuracy of PMI estimations. Further studies are needed to evaluate the effects of other commonly encountered drugs on insect development.