Micromorphology of immature stages of Sarcophaga (Liopygia) cultellataPandellé, 1896 (Diptera: Sarcophagidae), a forensically important fly

Abstract

The Sarcophagidae are one of the most numerous groups of Diptera in the world, consisting of many species of forensic interest, whose immature stages are useful in the estimation of postmortem interval. The immature stages of some species of forensic importance still remain unknown or undescribed, like in the case of Sarcophaga (Liopygia) cultellata Pandellé, 1986, a species restricted to the Iberian Peninsula, south of France and north of Italy, which shares a ecological niche with species of the same subgenus, e.g., Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830) and Sarcophaga (Liopygia) crassipalpis Macquart, 1839, making it necessary to lay the groundwork for a proper specific differentiation before it can be successfully applied in forensic practice. This study provides the first micromorphological description of all preimaginal stages of S. (L.) cultellata using light microscopy and scanning electron microscopy (SEM), the results of which allow the morphology of the main features to be followed during the immature life cycle. We propose a combination of features for distinguishing Liopygia from other sarcophagid subgenera, based on the current level of morphological knowledge of immature stages. S. (L.) cultellata can be differentiated from S. (L.) argyrostoma and S. (L.) crassipalpis in every immature stage by both light microscopy and SEM. The presence of tegumental warts and a fan-shaped anterior spiracle with a single row of 15-18 respiratory papillae allow distinguishing the third instar larvae of S. (L.) cultellata from other Sarcophaga species described hitherto by SEM. Identification keys based on light microscopy observations are provided, covering all the immature stages of Liopygia subgenus occurring in the Iberian Peninsula.

Third instar larvae of flesh flies (Diptera: Sarcophagidae) of forensic importance—critical review of characters and key for European species

“…Recently, Singh et al ( 2012 ) summarised the features most commonly used in the larval taxonomy of Sarcophagidae. They are as follows: the shape of particular elements of the cephaloskeleton, the configuration of anterior spiracles, the shape and distribution of spines in the spinose bands, the form and position of posterior spiracles, and the position and size of papillae around the entrance of the spiracular cavity (Greene 1925 ; Zimin 1948 ; Kano et al 1951 ; Sanjean 1957 ; Ishijima 1967 ; Nandi 1980 ; Sukontason et al 2010 ; Velásquez et al 2010 ; Ubero-Pascal et al 2015 ). Additionally, Zimin ( 1948 ) and subsequently a few other authors, in addition to the standard characters, proposed using the sculpture of the integument for species identification.…”

“…Characters relating to spinulation are widely used in the taxonomy of necrophagous Diptera (e.g. Erzinçlioğlu 1985 ; Wallman 2001 ; Szpila 2010 ; Grzywacz et al 2014 ), including Sarcophagidae (Zimin 1948 ; Sanjean 1957 ; Ishijima 1967 ; Nandi 1980 ; Ubero-Pascal et al 2015 ). Those most often applied are the distribution and degree of development of spinose bands on the abdominal segments.…”

“…In this situation, as is the case also for other ecozones, forensic entomology manuals recommend the mass rearing of the collected flesh fly larvae to adults for a precise species identification (Smith 1986 ; Byrd and Castner 2009 ). A few existing keys for species identification of larvae of necrophagous Sarcophagidae are restricted to local faunas of geographical regions far from Europe (Greene 1925 ; Zimin 1948 ; Bohart and Gressitt 1951 ; Kano et al 1951 ; Sanjean 1957 ; Ishijima 1967 ; Nandi 1980 ; Sukontason et al 2010 ) or, if referring to the European fauna, they cover narrow subsets of species (Velásquez et al 2010 ; Ubero-Pascal et al 2015 ). The recent monograph of Richet et al ( 2011 ) and the molecular work of Jordaens et al ( 2013 ) opened the possibility to overcome the problem of species identification of larvae of most species of European necrophagous flesh flies.…”

The first instar larva of two species of Miltogramminae (Diptera: Sarcophagidae) from the Middle East – examples of peculiar morphology

“…Draber-Mo nko et al 2009;Paños-Nicolas et al 2015;Ubero-Pascal et al 2015;Vairo et al 2015). Draber-Mo nko et al 2009;Paños-Nicolas et al 2015;Ubero-Pascal et al 2015;Vairo et al 2015).…”

“…Recent studies have provided extensive high-quality information on the larval morphology of the flesh flies (e.g. Draber-Mo nko et al 2009;Paños-Nicolas et al 2015;Ubero-Pascal et al 2015;Vairo et al 2015). Substantial progress has been made, particularly for the subfamily Miltogramminae, where early pre-imaginal stages of dozens of species have been described for the first time, or their morphology has been extensively revised (Szpila and Pape 2005a,b, 2007, 2008, 2013Szpila 2010;Pape and Szpila 2012).…”