Distinction among the puparia of three blowfly species (Diptera: Calliphoridae) frequently found on unburied corpses

Abstract

Key words: Calliphoridae -carrion insects -decomposition -forensic entomology -pupariaThe family Calliphoridae consists of carrion flies which may also feed on living tissues. These species are potentially dangerous to man and other animals since the larvae may cause myiasis and adults may transmit pathogens. The diseases transmitted by these flies cause substantial losses to the cattle industry (Norris 1959, Zumpt 1965, Greenberg 1971, 1973, Richard & Gerrish 1983. The genus Chrysomya was introduced in Brazil from Africa (Zumpt 1965) with the first records being from the states of Paraná (Imbiriba et al. 1977) and São Paulo (Guimarães et al. 1978). Chrysomya species are currently found from the southern United States to southern Brazil (Jiron 1979, Gagné 1981, Baumgartner & Greenberg 1984.Insects are important in carcass decomposition, and calliphorids, which are among the most abundant and best studied carrion insects have been extensively used as indicators of the post mortem interval (death time) and of corpses translocation. These flies are therefore a valuable tool for forensic medicine (Megnin 1894, Smith 1986, Catts & Haskell 1990.In this study, we show that it is possible to distinguish among three species (C. megacephala, C. putoria and Cochliomyia macellaria) based on characteristics of their pupae and puparia. MATERIALS AND METHODSCultures (F1) of each species were maintained in cages (25 cmx25 cmx30 cm) covered with mosquito nets, at 25 ± 1 o C, 60% relative humidity and a 12 h photoperiod. The flies were fed raw bovine liver for four days immediately after emergence and with water and sugar ad libitum thereafter. Eggs of the three species were collected from these cultures using ground raw bovine meat. Before hatching, the eggs were transferred from the meat to vials containing artificial culture medium (Leal et al. 1982) growth. The vials were kept under the same conditions of the F1 cultures. When the larvae reached the third instar, they were transferred to vials filled with sawdust for pupating.After the F2 adults of each species had emerged, specimens of their puparia (without any cleaning) were examined with a binocular microscope to assess interspecific differences in the posterior spiracle region. In 30 puparia from each species, the distance between the two peritrema was measured. These distances were compared by analysis of variance followed by the Student-Newman-Keuls test (Zar 1996), with the critical value set at p = 0.05. RESULTSC. putoria puparia had six very conspicuous tubercles in the perispiracular region whereas in

Identifying fly puparia by clearing technique: application to forensic entomology

“…It is difficult to identify the species because of similarities in the puparia, and rearing them to adulthood may fail. Efforts have been made to identify fly puparia by means of morphological determination under light microscopy (Reiter and Wollenek 1983;Amorim and Ribeiro 2001;Whitworth 2002Whitworth , 2003, scanning electron microscopy (SEM; Kitching 1976;Liu and Greenberg 1989;Siriwattanarungsee et al 2005;Sukontason et al 2006b) or determination the cuticular hydrocarbon composition (Ye et al 2007). In the present study, we describe the technique used to pale the integument of puparia, which allows species identification and the morphometric analysis of seven fly species that are of forensic importance in Thailand.…”

Morphology of the puparia of the housefly, Musca domestica (Diptera: Muscidae) and blowfly, Chrysomya megacephala (Diptera: Calliphoridae)

“…Puparia of flies, particularly those of forensic importance, are morphologically similar in general appearance; thus, making them difficult to identify. Studies published by Amorim and Ribeiro (2001) documented distinctive features between puparia of the three blowflies species, C. megacephala, Chrysomya putoria and Cochliomyia macellaria, using binocular microscope. However, with SEM observation, the fly puparia can be described in greater detail.…”

La Entomología Forense y el Neotrópico

“…El primero es el más abundante durante la fase de putrefacción (fresca, hinchazón y putrefacción activa), en contraste con los segundos cuyo incremento se observa en la fase seca (putrefacción avanzada y restos de esqueletos), por lo que son las dos familias de mayor potencial forense [18]. También se han identificado otros tipos de artrópodos, pero estos son típicamente comensales oportunistas que toman ventaja de las circunstancias [4,19].…”