HomeJournal of Multidisciplinary Studiesvol. 13 no. 1 (2024)

Insects on Decomposing Pigs and their Forensic Importance at a University in Nigeria

Maduamaka Abajue

 

Abstract:

The use of insects to estimate post-mortem interval (PMI) of cadavers by forensic entomologists, is an innovative science enshrined in the medico-criminal system of the developed world. The science is dependent on the biology of insect species that are found in decomposing cadavers. Thus, insect species that are found on decomposing pigs as model to human cadaver, was studied during the rainy and dry seasons of 2021 in a University forest in Nigeria. The decomposition stages (fresh through skeletonization) of the pig cadavers were monitored, and insects found on them were collected with a sweep net, visually observed, and handpicked. They were identified morphologically using insect identification keys with the aid of a dissecting microscope. The tissues of the pig cadavers decomposed completely in 14 and 10 days, respectively, for dry and rainy seasons. Twenty-seven insect species belonging to the orders; Diptera, Coleoptera, and Hymenoptera were identified. The dipterans consist of the families Calliphoridae, Muscidae, Ulidiidae, and Stratiomyidae. The coleopteran families are the Carabidae, Chrysomelidae, Cleridae, Dermestidae, Histeridae, Scarabaeidae, and Staphylinidae, while Formicidae is the only family for the hymenopteran. The dipteran species were the first group to visit the cadavers during fresh, bloated, and wet decay stages while the coleopterans visited during wet and dry decay stages thus, creating a succession pattern on the cadavers. The insect species that aided the cadaver decomposition at different stages are discussed as forensic indicators, which could be useful as PMI estimators of the study area.



References:

  1. Abajue, M.C., & Ewuim, SC. (2016). Forensic entomology: decomposing
    pig carrion and its associating insects in Okija, Anambra State Nigeria.
    American Journal of Biology and Life Sciences, 4(2), 6-11.
  2. Abajue, M.C., & Ewuim, S.C. (2020). Evaluation of activities of dipteran
    maggots on a poisoned pig cadaver at Nnamdi Azikiwe
    University, Nigeria. Egyptian Journal of Forensic Sciences, 10(33), 1-10.
  3. Abajue, M.C., Ewuim, S.C., & Akunne, CE. (2013). Insects associated
    with decomposing pig carrions in Okija, Anambra State, Nigeria. The Bioscientist, 1(1), 54-59.
  4. Abajue, M.C., Ewuim, S.C., & Akunne C.E. (2017). Insect larvae
    recovered from decomposing pig carrions in Okija, Anambra State, Nigeria. Animal Research International, 14(2), 2764 –
  5. Abajue, M.C., Ewuim, S.C., & Uhuo, C.A. (2021). Succession of three
    dipteran maggot families on poisoned pig cadavers. International Journal of Entomology Research, 6(3), 140-147.
  6. Abouzied, E.M. (2014). Insect colonization and succession on rabbit
    carcasses in southwestern mountains of the Kingdom of Saudi Arabia. Journal of Medical Entomology, 51(6), 1168–1174.
  7. Amendt. J., Krettek, R., & Zehner, R. (2004). Forensic entomology.
    Naturwissenschaften, 91, 51-65.
  8. American veterinary medical association (AVMA, 2014). Guidelines for
    the euthanasia of animals. Assessed online on January, 03, 2014.
  9. Benbow, M.E., Lewis, A.J., Tomberlin, J.K., & Pechal, J.L. (2013)
    Seasonal necrophagous insect community assembly during
  10. vertebrate carrion decomposition. Journal of Medical Entomolology, 50(2), 440-450.
  11. Benceke, M. (2004). Forensic entomology: Arthropods and corpses. In:
    Tsokos, M. (ed) Forensic pathology review, volume II. Humana
    Press.
  12. Bugelli, V., Gherardi, M., Focardi, M., Pinchi, V., Vanin, S., &
    Campobasso, C.P. (2018). Decomposition pattern and insect
    colonization in two cases of suicide by hanging. Forensic Sciences
    Research, 3(1), 94-102.
  13. Byrd, J.H., & Castner, J.L. (2010). Forensic entomology: The utility of
    arthropods in legal investigations (2nd ed). CRC press.
  14. Cordeiroa, C., Ordóñez-Mayánd, L., Lendoiroe, E., Febrero-Bandef, M.,
    Vieirab, D.N., & Muñoz-Barúse, J.I. (2019). A reliable method for
    estimating the postmortem interval from the biochemistry of the
    vitreous humor, temperature and body weight. Forensic Science
    International, 295, 157–168.
  15. Cruz, T.M., Barbosa, T.M., Thyssen, P.J., & Vasconcelos, S.D. (2021).
    Diversity of Diptera species associated with pig carcasses in a
    Brazilian city exposed to high rates of homicide. Papeis Avulsos
    de Zoologia, 61, e20216101.
  16. Dekeirsschieter, J., Frederickx, C., Verheggen, F.J., Boxho, P., &
    Haubruge, E. (2013). Forensic entomology investigations from
    Doctor
  17. Marcel Leclercq (1924-2008): A review of cases from 1969 to 2005.
    Journal of Medical Entomology, 50, 935-954.
  18. Dupont., F.Y.F., Champlain, D., Cyrille, A.W.J., & Félix, B.B.C. (2011).
    A preliminary study of arthropod associated with carrion in
    Yaounde, Cameroon: A first step in forensic entomology in
    Central Africa. Journal of Ecology and the Natural Environment,
    3(6), 215-220.
  19. Ekanem, M.S., & Dike, M.C. (2010). Arthropods Succession on pig
    carcasses in Southeastern Nigeria. Papeis Avulsos de Zoologia,
    50(35), 561-570.
  20. Ekrakene, T., & Iloba, B.N. (2011). One death, many insect species yet
    one insects generation. Journal of Entomology, 8, 27-39.
  21. El-Gawad, A.A., Badawy, R.M., Abd El-Bar, M.M., Mohamed, A., &
    Kenawy, M.A. (2019). Successive waves of dipteran flies
    attracted to warfarin-intoxicated rabbit carcasses in Cairo, Egypt.
    The Journal of Basic and Applied Zoology, 80(56), 1-10.
  22. Galloway, A., Birkby, W.A., Jones, A.M., Henry, T.E. and Parks, B.O.
    (1989). Journal of Forensic Sciences, 34(3), 607-616.
  23. Gennard, D.E. (2007). Forensic entomology: An introduction. John
    Wiley.Gomes, L., Gomes, G., & Desuo, I.C. (2009). A
    preliminary study of insect fauna on pig carcasses located in
    sugarcane in winter in southeastern Brazil. Medical and
    Veterinary Entomology, 23, 155–159.
  24. Lutz, L., Williams, K.A., Villet, M.H., Ekanem, M., & Szpila, K. (2018).
    Species identification of adult African blowflies (Diptera:
    Calliphoridae) of forensic importance. International Journal of
    Legal Medicine, 132, 831-842.
  25. Lutz, L., Zehner, R., Verhoff, M.A., Bratzke, & Amendt, J. (2021). It is
    all about the insects: a retrospective on 20 years of forensic
    entomology highlights the importance of insects in legal
    investigations. International Journal of Legal Medicine, 135,
    2637-2651.
    Medler, J. Insects of Nigeria-checklist and bibliography. Memoirs of the
    American Entomological Society, 30, 1-919.
  26. NDES, (2001). Biological environmental research report, Rivers State
    University of Science and Technology (RUST) Port Harcourt,
    Nigeria. 46: 251.
  27. Okiwelu, S.N., Ikpamii, T., & Umeozor, O.C. (2008). Arthropods
    associated with mammalian carcaasses in Rivers State, Nigeria.
    African Journal of Biomedical Research, 11: 339-342.
  28. Sanford, M.R. (2017). Insects and associated arthropods analyzed during
    medicolegal death investigations in Harris County, Texas, USA.
    PLoS ONE, 12(6), e179404