| dc.description.abstract | Postmortem interval (PMI) is the length of time that occurs between death of a person and the subsequent discovery of the body. PMI can be determined in a variety of ways depending on how long the body has been exposed to the environment. Forensic entomologists can use the identity and growth stages of insects to determine the PMI. During the initial stages of decomposition, the primary insects to attack the body are blow flies and flesh flies. The abundance and age of the fly larvae are used to calculate the PMI according to established life cycle times for each species. Several factors can alter the apparent PMI via alterations in the insect activity. These factors include temperature, humidity, sunlight, and chemicals present in or on the body. This research focused on the alteration of PMI by insecticides applied to the body after death. Readily available insecticides were chosen from three classes of pesticides: malathion, an organophosphate; carbaryl, a carbamate; and permethrin, a pyrethroid. Pig carcasses were coated with a 0.5% solution of one of the three pesticides and placed in a remote site protected from predation. The pigs were monitored daily for the appearance of fly larvae. Larvae were collected and analyzed by GC/MS for the presence of the insecticides. The insecticides deterred the arrival of flies in the following decreasing potency: permethrin, carbaryl, and malathion. | |
