Effects of Tramadol Hydrochloride (an opioid) Injection on the Developmental Rate, Larval Weights and Body Lengths of the Lucilia sericata (Meigen) (Diptera: Callophoridae) Reared on Rabbit (Orctylagus cunicunus) Carrions

Abstract

This research work was carried out to ascertain the effect of tramadol hydrochloride (an opioid) on the body lengths and weights of the larvae and the developmental rate of the blowfly Lucilia sericata (Diptera: Calliphoridae) reared on rabbit carrions injected with 150ml (50ml/mg) ( 1/2LD50), 300ml (LD50), 600ml (2LD50) dosages and control (no tramadol). These dosages are the same with those that are normally observed in homicide and abusive cases involving tramadol hydrochloride injection overdose. Mettler Toledo weighing balance (with sensitivity of 0.001-1g) was used to record the weights of the larvae and the pair of compass was used to measure the body length and read with a transparent meter rule while all stages of the insect were monitored and observations recorded. The mean maximum lengths and weights were reached (17.50mm and 0.0930g for 2LD50 at 96hrs, 14.13mm and 0.0810g for LD50 at 96hrs and 13.13mm and 0.0510g for the LD50/2 at 108hrs) earlier in those larvae reared on the rabbits injected with tramadol hydrochloride than those of the control (11.38mm and 0.0500g at 108hrs). However the total developmental period appreciated immensely with increased injected dosages and ranged from 362.15hrs in the 2LD50, 345.15hrs in the LD50 and 309.46hrs in the LD50/2. Whereas the control mean developmental period is 280.25hrs. There was significant differences in the mean body length (H ═ 0.174, P>0.05) and the mean larval body weight (H ═ 0.055, P>0.05) using the non-parametric Kruskal Wallis analysis. Arising from the results therefore, special caution must be taken in the application of the toxicological analysis of insect larvae data of fatal tramadol and other drug related cases.
Keywords: Entomotoxicology, insects, Lucilia sericata, forensic entomology, carrions