Morphology of immature stages of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae) for use in forensic entomology applications

Abstract

In forensic investigations, all immature stages of flies (egg, larvae, and puparium) can serve as entomological evidence at death scenes. These insects are primarily used to estimate the post mortem interval (PMI), but can also be involved in the analysis of toxic substances, determining manner of death, and in indicating relocation of a corpse in homicide cases. In this study, we present the morphology of the egg, larvae, and puparium of Hemipyrellia ligurriens, a blow fly species of forensic importance in Thailand. Examination was conducted using scanning electron microscopy (SEM). The egg stage was found to display a relatively wide plastron region (or median hatch line area) that spans almost the entire length of the egg. The median hatch line is oriented in an upright position. External chorionic sculpture of the egg is present in a hexagonal pattern whose reticular boundaries are slightly elevated. In the larval stages, the most prominent morphological changes were detected upon comparison of the first to the second instar; whereas, the differences between second and third instar larvae were less obvious outside of the increase in number of posterior spiracular slits. Most of the major differences involve body size and structure of the anterior and posterior spiracles. Each anterior spiracle in both the second and third instars projects five to seven papillae apically. Each posterior spiracular disc of a third instar exhibits a complete peritreme, three spiracular slits, and a prominent button that is ventromedially located. The puparium is coarctate and features a clustered bubble membrane comprised of approximately 57 mammillate structures positioned dorsolaterally on each side of the first abdominal segment in young puparia. This feature is replaced by short, tubular respiratory horns in aged puparia. This study provides more detailed exposure of important morphological features that can be used for accurate identification of immature stages of H. ligurriens. Information presented can aid in forensic investigations involving this fly species.

Ultramorphological characteristics of immature stages of a forensically important fly Parasarcophaga ruficornis (Fabricius) (Diptera: Sarcophagidae)

“…Similar structure is also present in other species such as Sarcophaga forceps (Kirk-Spriggs 2000), however, this prominence is less pronounced in P. ruficornis. The two distinct groups of papillae on the terminal organ in P. ruficornis were similarly arranged as in Lucilia cuprina (Sandeman et al 1987), Musca domestica (Chu-Wang and Axtell 1971), sepsids (Meier 1995), Piophilia casei (Sukontason et al 2001a) and Hemipyrellia ligurriens (Sukontason et al 2008). The papillary sensillae may serve a dual function of chemoreception and mechanoreception.…”

Technical note: Development of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae) at constant temperatures: Applications in estimating postmortem interval

“…It is quite fecund, with a relatively short adult lifespan [8]. The morphological features of H. ligurriens at all stages and the developmental time of each stage under natural ambient conditions (26.7 AE 0.6 8C) are well established [7,9,10].…”

Blow Fly (Diptera: Calliphoridae) in Thailand: Distribution, Morphological Identification and Medical Importance Appraisals

“…Pupa stage: The pupa is mahogany brown to dark brown in color and coarctate and barrel shaped. Morphology of puparium has been studied widely under LM [29] and SEM [30][31][32][33][34][35]. A simply key to identify the puparium of some blow fly species of Thailand was summarized by Sukontason et al [29].…”

“…A simply key to identify the puparium of some blow fly species of Thailand was summarized by Sukontason et al [29]. The main characteristics for identification include body appearance (with or without tubercle), such as the 3 rd thoracic segment to 1 st abdominal segment, distance between right and left posterior spiracles, number of bubble membranes and papillae on the anterior spiracle [29][30][31][32][33][34][35].…”