Identification of insects colonizing carrions of tramadol-intoxicated rabbits and guinea pigs in relation to seasonal variances in Cairo, Egypt

Abstract

This study gives out the identification of insect faunal waves colonizing decomposing carrions of rabbits and guinea pigs treated with certain drug agent (tramadol) in Cairo, Egypt. Each of six rabbits and six guinea pigs is divided into 2 groups, where the first was killed by tramadol and the second group was killed by asphyxia as a control experiment. Generally, decomposition process was observed to have a slower rate in winter. Reaching to the skeletal stage was delayed in tramadolintoxicated carcasses in comparing to the control carcasses. A total of 12966 arthropod individuals (Immature stages and adults) were collected. In concern of class Insecta, 67 species belonging to 6 Insecta orders and 2 Arachnida orders, 37 families and 51 genera were identified from this study during winter and summer seasons. Significantly lower numbers of immatures were observed and collected in the present study from the treated carcasses. The proportions of adult insects were also significantly different in control carcasses when compared with tramadol intoxicated ones in both winter and summer season for both rabbits and guinea pigs. This study provides background for the influence of tramadol on the colonizing wave of arthropod fauna which is of relevance to forensic science. We can conclude that drugs and toxins present in a decomposing body may alter the rate of insect invasion of that body.

Comparative Study on Forensic Insects encountered on Rabbit Corpses killed with different methods in Upper Egypt

“…Herein, it was observed that the number of cadaver colonized insects particularly calliphorids and sarcophgids was very low at the fresh stage in all study cases during all seasons then gradually increased in both bloating and active decay stages which reached to the maximum number because the odor become obvious and the cadavers have been already occupied by eggs and larvae and then decreased again at both of the advanced and dry stages. This result is agreed with Hamdy et al (2022).…”

“…Likewise, Abd El-bar and Sawaby (2011) recorded only 16 species, Al-Shareef and Al-Mazyad ( 2016) reported fewer forensic insects (9 species), Aly et al (2017) recorded 18 species and El-Samad et al ( 2021) listed 17 species. However, some other studies collected more insect species such as Wang et al (2008), Abd El-Bar et al (2016 and Hamdy et al (2022) collected 47 species, 36 species and 67 species, respectively. This difference in number of the collected species may be attributed to the used carrion size, climatic conditions, the geographic region, the killing methods and antemortem ingestion of drugs or toxins (Hamdy et al, 2022).…”

“…However, some other studies collected more insect species such as Wang et al (2008), Abd El-Bar et al (2016 and Hamdy et al (2022) collected 47 species, 36 species and 67 species, respectively. This difference in number of the collected species may be attributed to the used carrion size, climatic conditions, the geographic region, the killing methods and antemortem ingestion of drugs or toxins (Hamdy et al, 2022).…”

“…This is not compatible with Abd El-bar and Sawaby (2011) in Qalyubiya Governorate in Egypt, who carried their study with organophosphate insecticide in summer season which found Calliphoridae was the predominant family in their work. Also, Hamdy et al (2022) in Cairo, Egypt, conducted their study with tramadol hydrochloride in winter and summer seasons where stated that Dermestidae (Order: Coleoptera) was the predominant family in winter, whilst Formicidae (Order: Hymenoptera) was the most predominant family in summer.…”

“…The most accurate and possibly approach to estimate PMI after 72 hours after death is the forensic entomology (Sharma et al, 2022). Forensic entomology can be used not only to determine the PMI but also, in detect the cause of death as drug abuse or poisoning by chemicals (Hamdy et al 2022).…”