ISSN 2347-6893 Volume 9 Number 1 Journalof Advances in Biology 1783 | Page council for Innovative Research April 2016 www.cirworld.com SEASONALITY OF INSECT SUCCESSION ON REMAINS OF RABBITS TREATED WITH AMITRIPTYLINE (ANTIDEPRESSANT DRUG) IN ALEXANDRIA, EGYPT. Lamia M. El-Samad 1 and Mariam H. Youssef 2 Dr_lamialina11@yahoo.com 1,2 Department of Zoology, Faculty of Science, Alexandria University, Alexandria, Egypt ABSTRACT In 2011 and 2012, seasonal field studies on vertebrate carrion decomposition and its associated arthropod fauna were carried out on sixteen healthy domestic rabbits, Oryctolagus cuniculus L., killed by asphyxia (control) and with different doses of a commonly used antidepressant drug amitriptyline (test). Amitriptyline involved in up to 33% of all fatal poisonings, second only to analgesics. Five decomposition stages were recognized: fresh, bloat, active decay, advanced decay and dry. Carcasses in summer and spring decayed at a much faster rate than in fall and winter. The presence of the amitriptyline in decomposing tissues, influences the development and pattern of carrion feeding insects and alter postmortem interval (PMI) estimates based on the rate of larval and puparial development. It should be pointed out that the presence of this drug alter the successional model in Alexandria, Egypt. Diptera was the predominant group, were as Coleoptera ranked 2nd. Calliphorids and Sarcophagids were the most important arthropod invaders of cacassess because of the influence they had on the rapid deterioration of the carcasses. It was of an interest to note that Formicidae was present in all carcasses, mostly in the early stages of decomposition. Carcasses which had been killed by different doses of amitriptyline were found to be unsuitable for certain flies. This study provide an additional knowledge in the context of Egyptian forensic entomology and the influence of amitriptyline which is of relevance to forensic science. Indexing terms/Keywords Forensic entomology – Postmortum interval – Arthropod succession – Antidepressant drug – Amitriptyline. Academic Discipline And Sub-Disciplines Entomology-forensic entomology. INTRODUCTION Forensic entomology is the science of collecting and analyzing insect evidence to aid in forensic investigations (Amendt et al., 2011). Medico-legal forensic entomology cover evidence that may be gathered through arthropod studies at events such as murder, suicide, rape, physical abuse and contraband trafficking (Catts and Goff, 1992). The typical questions posed to the medicocriminal entomologist involve estimating of the time a decedent has been dead (the “ postmortem interval’ or PMI) and less frequently, the place (situs) where death occurred (Hall, 2001). Together, arthropod succession and insect development have been successfully used to determine the PMI in criminal investigations (Amendt et al., 2004; Arnaldos et al., 2005; Matuszewski et al., 2010; Abd El-bar and Sawaby, 2011; Nazni et al., 2011).Succession of insects on carrion is forensically important for two reasons. Firstly, if the pattern of succession is known for a given set of circumstances, one may use it to estimate postmortem interval (PMI) with succession-based method (Goff and Flynn, 1991; Schoenly et al., 1992; Schoenly et al., 1996; Wells and LaMotte, 2001; Matuszewski et al., 2010). Secondly, knowledge on sequence and time of carcass colonization by immature of different taxa is necessary to properly place in time the minimum PMI estimated with development-based method (Smith, 1986; Benecke, 1998; Goff, 2000; Wells and LaMotte, 2001; Greenberg and Kunich, 2002; Arnados et al., 2005; Matuszewski et al., 2010). Succession studies need to be conducted in as many diverse geographic areas as possible, since there can be differences in insect fauna between geographic areas. In some cases, the insect fauna in a specific area can change over time. For example, the black soldier fly, Hermetia illucens (Linnaeus),was found for the first time in Italy as necrophagous in 1997 (Turchetto et al., 2001). Furthermore, insects may serve as important alternative species for toxicological analysis in cases where human samples are not available for this purpose (Goff and Lord, 1994; Verma and Reject Paul, 2013). Over the past several years, drug- related deaths have increased. It has been shown that the presence of substance such as drugs (cocaine, heroin, amitriptyline, etc.) and toxins in the carrion may serve to alter both the rate of development of individual insect species and the pattern of succession onto the carrion (El-Ghaffar et al. 2008). Tricyclic antidepressants (TCAs) are heterocyclic chemical compounds used primarily as antidepressants. The TCAs were first discovered in early 1950s and were subsequently introduced later in the decade (Carson, 2000). They are named after their chemical structure, which contain three rings of atoms (Figure 1). The TCAs include the following agents which are predominantly serotonin and/or norepinephrine reuptake inhibitor: Amitriptyline (Elavil, Tryptizol, Laroxyl). The severe morbidity and mortality associated with these drugs is well documented due to their cardiovascular and neurological toxicity. Additionally, it is a serious problem in the pediatric population due to their potential toxicity (Rosenbaum and Kou, 2005) and the availability of these in the home when prescribed for bed wetting and depression. Amitriptyline involved in up to 33% of all fatal poisonings, second only to analgesics (Thomas et al., 1996).