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In forensic entomology, entomotoxicology is the analysis of toxins in arthropods (mainly flies and beetles) that feed on carrion. Using arthropods in a corpse or at a crime scene, investigators can determine whether toxins were present in a body at the time of death. This technique is a major advance in forensics; previously, such determinations were impossible in the case of severely decomposed bodies devoid of intoxicated tissue and bodily fluids. Ongoing research into the effects of toxins on arthropod development has also allowed better estimations of postmortem intervals. ==Effects of toxins on arthropods== Drugs can have a variety of effects on development rates of arthropods. Morphine, heroin, cocaine, and methamphetamine are commonly involved in cases where forensic entomology is used. The stages of growth for insects provides a basis for determining a cause in altered cycles in a specific species. An altered stage in development can often indicate toxins in the carrion on which the insects are feeding. Beetles (Order: Coleoptera) and beetle feces are often used in entomotoxicology, but the presence of toxins is often the result of the beetles’ feeding on fly larvae that have been feeding on the carrion containing toxic substances. Flies (Order: Diptera) are the most commonly used insect in entomotoxicology.〔 Gagliano-Candela, R. and Aventaggiato, L. “The detection of toxic substances in entomological specimens.” ''International Journal of Legal Medicine'' 114 (2001): 197-203.〕 Through the study of ''Sarcophaga (Curranea) tibialis'' larvae, barbiturates were found to increase the length of the larval stage of the fly, which will ultimately cause an increase in the time it takes to reach the stage of pupation.〔Musvasva, E. and others. “Preliminary observations of the effects of hydrocortisone and sodium methohexital on development of Sarcophaga (Curranea) tibialis Macquart (Diptera: Sarcophagidae), and implications for estimating post mortem interval.” ''Forensic Science International'' 120 (2001): 37-41.〕 Morphine and heroin were both believed to slow down the rate of fly development.〔Introna, Francesco and others. ”Entomotoxicology.” ''Forensic Science International'' 120 (2001): 42-47.〕〔Carvalho, Lucila M.L.; Linhares, Arício X.; and Trigo, José Roberto. “Determination of drug levels and effect of diazepam on the growth of necrophagous flies of forensic importance in southeastern Brazil.” ''Forensic Science International'' 120 (2001): 140-144.〕 However, closer examination of the effects of heroin on fly development has shown that it actually speeds up larval growth and then decreases the development rate of the pupal stage. This actually increases the overall timing of development from egg to adult. Research of ''Lucilia sericata'' (Diptera: Calliphoridae), reared on various concentrations of morphine injected meat, found higher concentrations of morphine in shed pupal casings than in adults.〔 Bourel, Benoit and others. “Morphine extraction in necrophagous insects remains for determining ante-mortem opiate intoxication.” ''Forensic Science International'' 120 (2001): 127-131.〕 Cocaine and methamphetamine also accelerate the rate of fly development.〔 Some effects depend on the concentration of the toxin while others simply depend on its presence. For example, cocaine (at the lethal dose) causes larvae to “develop more rapidly 36 (to 76) hours after hatching”.〔 The amount of growth depends on the concentration of cocaine in the area being fed upon. The amount of methamphetamine, on the other hand, affects the rate of pupal development. A lethal dose of methamphetamine increases larval development through approximately the first two days and afterwards the rate drops if exposure remains at the median lethal dosage. The presence of methamphetamine was also found to cause a decrease in the maximum length of the larvae.〔 Along with changes in development rates, extended periods of insect feeding refrain and variation in the size of the insect during any stage of development, can also indicate the presence of toxic substances in the insect’s food source.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Entomotoxicology」の詳細全文を読む スポンサード リンク
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