(Diptera: Calliphoridae) Larval Key: Subfamily Chrysomyinae
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The Development of a Forensically Relevant Blow Fly (Diptera: Calliphoridae) Larval Key: Subfamily Chrysomyinae Andrew Noblesse, Lauren Weidner, Ph.D., School of Mathematical and Natural Sciences, Arizona State University Abstract Results Conclusions As forensic entomologists’ time of colonization (TOC) estimations rely on species identification, Key to Forensically Relevant Chrysomyinae Third Instar Larvae Across the United States With this inclusive pictorial identification key, forensic rearing larval specimens to adulthood is currently required. To remedy issues associated with 1. Larva with rows of conspicuous tubercle (Fig. 1a) . Chrysomya rufifacies entomologists will be able to make their TOC estimations the rearing process, larval identification should be made more accessible. For the species more quickly and efficiently. Identifying samples in their included here, three populations varying in region were collected, each with a minimum of Larva without tubercles (Fig. 1b) . 2 larval phase will reduce the need for rearing, which has 100 third instar larvae analyzed. Larvae were observed microscopically to verify the 2. Oral sclerite pigmented (Fig. 2a) . 3 several other limitations associated with it. These include accuracy of the key’s characterizations. Of the species that were available for examination, Oral sclerite unpigmented (Fig. 2b) . 4 rearing material costs, the maintenance of a rearing space, each were keyed out appropriately with the morphological characteristics listed. There was a and the potential for low survivorship. So far, the key’s limited number of specimens that presented with contradictory morphology. Overall, the 3. Oral sclerite partially pigmented, visible as dark spot (Fig. 2a) . Chrysomya megacephala accuracy has been verified for four of the seven species. publication of this inclusive pictorial key will eventually provide forensic entomologists the Oral sclerite fully pigmented, visible as dark spike (not pictured) . Compsomyiops callipes opportunity to identify larvae collected from a scene without the need to collect live 4. Pigmented spines above anus forming a V-shape (Fig. 3a) . Cochliomyia macellaria specimens to identify as adults. This decrease the time needed for analyses and reduce the Pigmented spines above anus form a sporadic, ovular cluster (Fig. 3b; circled) . 5 financial and physical limitations of needing to rear specimens to adulthood. 5. Medial posterior papillae (P1) well developed (Fig. 4) . 6 Further Plans Medial posterior papillae (P1) weakly developed (not pictured) . Cochliomyia hominivorax This key will continue to be developed for the Chrysomyinae 6. Medial posterior papillae (P1) relatively large (not pictured) . Protophormia terranovae subfamily, as well as the Lucilinae and Calliphorinae Introduction at 25 °C subfamilies by the Forensic Entomology Weidner Lab. All Medial posterior papillae (P1) relatively small (Fig. 4) . Phormia regina Forensic entomology is the use of insects in criminal and civil cases. In cases involving human work will aim for publication. remains, forensic entomologists are asked to provide a time of colonization (TOC) estimation based on the insects present and their developmental patterns. This estimation relies upon the identification of blow flies (Diptera: Calliphoridae) by species, as development is species dependent. This estimation is then related to a minimum postmortem interval (mPMI), or the Acknowledgments amount of time that has elapsed since an individual has died. Currently, morphological identification is best performed on adult flies, which must be reared from their immature Thank you to the following individuals for their contributions: stages if larvae are collected. However, this requires live specimens to be collected from Andrew Meeds, Chelsea Howell, Morgan Kincade. Thank scenes, and can present several challenges. These include a delay in the production of formal you to NCUIRE for funding this project. reports, as well as the financial burden of needing rearing materials and space. While some larval identification keys have been published, they are incomplete and to date, an all- inclusive pictorial larva key does not exist. Literature cited Figure 2a. Oral sclerite partially pigmented, Figure 2b. Oral sclerite unpigmented Figure 1a. Larva with rows of Figure 1b. Larva without tubercles visible as dark spot (indicated by arrow). (indicated by arrow; P. regina shown). Erzinclioglu, Y. Z. (1984). Studies on the morphology and taxonomy of conspicuous tubercles. (C. megacephala shown). the immature stages of Calliphoridae, with analysis of phylogenetic Materials and methods relationships within the family, and between it and other groups in the Cyclorrhapha (Diptera) (Doctoral dissertation, Durham The written key was constructed using pre-existing literature. The key includes the following University). species: Chrysomya rufifacies (Macquart), Chrysomya megacephala (F.), Compsomyiops callipes Szpila, K. (2009). Key for the identification of third instars of (Bigot), Cochliomyia macellaria (F.), Cochliomyia hominivorax (Coquerel), Protophormia European blowflies (Diptera: Calliphoridae) of forensic terranovae R-D, Phormia regina (Meigen). Three larval populations, each from a separate importance. In Current concepts in forensic entomology (pp. 43- region within the US, were collected for each species, with a minimum of 100 specimens per 56). Springer, Dordrecht. population analyzed. Specimens were observed under a stereozoom microscope to verify the Wells, J. D., Byrd, J. H., & Tantawi, T. I. (1999). Key to third-instar key’s accuracy, and photographs were taken using a Zeiss Axiocam 305 color camera, Chrysomyinae (Diptera: Calliphoridae) from carrion in the continental United States. Journal of Medical Entomology, 36(5), mounted on a Zeiss Axio Zoom.V16 microscope with Zen 3.0 blue edition software for Figure 3b. Anal spines in a sporadic, Figure 4. Posterior end with labeled papillae Figure 3a. Anal spines forming a V shape. 638-641. incorporation into the final publication. ovular cluster (circled; P. regina shown). (P. regina shown)..