- Email: [email protected]
Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae)
Egyptian Journal of Forensic Sciences (2015) xxx, xxx–xxx
H O S T E D BY
Contents lists available at ScienceDirect
Egyptian Journal of Forensic Sciences journal homepage: http://www.journals.elsevier.com/egyptian-journal-of-forensic-sciences
Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae) Raja M. Zuha a,*, Sheril June Ankasha b, R. Henry L. Disney c, Baharudin Omar b a Forensic Science Program, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia b Biomedical Science Program, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia c Department of Zoology, University of Cambridge, Downing St, Cambridge CB2 3EJ, United Kingdom
Received 29 May 2015; revised 10 August 2015; accepted 6 September 2015
KEYWORDS Decomposition; Indoors; PMI; Scuttle flies; Phoridae
Abstract Scuttle flies (Diptera: Phoridae) are a diversified insect group of forensic importance. Their frequent presence on human corpses indoors and in concealed environments can be the sole indicators to estimate the minimum post mortem interval (PMImin). However, bionomics of scuttle flies on decomposing animal carcasses are rarely documented indoors. The objective of this research is to observe and document the occurrence of scuttle flies on decomposing animal carcass placed inside a portable cabin maintained at room temperature (25.0 °C) in Bangi, Malaysia. This study was conducted in two rounds for a period of 40-day each and samplings were carried out in different intervals. Adult scuttle flies were aspirated directly from the carcass and preserved in 70% ethanol. Their larvae and pupae were reared until adult stage to facilitate identification. Megaselia scalaris (Loew), Megaselia spiracularis (Schmitz) and Dohrniphora cornuta (Bigot) were the scuttle flies found on the carcasses with M. scalaris being the earliest and dominant to colonize the body. This cosmopolitan species proved to be the best indicator to estimate PMImin indoor but in the increased presence of other fly species, it might be relegated to a secondary role. The scuttle flies were also found to coexist with other dipterans of forensic importance in an indoor environment, mainly Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae). This information expands the knowledge on the bionomics of scuttle flies on decomposing animal remains indoors. Ó 2015 Hosting by Elsevier B.V. on behalf of The International Association of Law and Forensic Sciences (IALFS).
* Corresponding author. Tel.: +60 193930366, office: +60 389214833. E-mail address: [email protected] (R.M. Zuha). Peer review under responsibility of The International Association of Law and Forensic Sciences (IALFS).
1. Introduction In forensic entomology, decomposition study helps to identify insects of forensic importance and estimate the minimum post mortem interval (PMImin). By using animal carcasses as
http://dx.doi.org/10.1016/j.ejfs.2015.09.002 2090-536X Ó 2015 Hosting by Elsevier B.V. on behalf of The International Association of Law and Forensic Sciences (IALFS). Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
2 decomposition models, the ecological relationship between insects and decaying human remains can be demonstrated.1,2 Succession analysis from the predictable sequence of carrionvisiting insects systematically tabulates the occurrence of insects in various conditions such as in natural outdoor or human-made indoor environments, and this information is very useful in forensic investigations.3,4 Indoor environments usually limit the presence of blow flies, or at least, delay their arrival to the human remains.5 When investigating PMImin of corpses found indoors, access to the body by insects is one of the many crucial factors that affect decomposition rate.6 In the context of forensic entomology, the earliest sarcosaprophagous insect that could gain entry to colonize corpse indoors can be the primary indicator for PMI estimation.7,8 This often refers to the diminutive scuttle flies (Diptera: Phoridae) that can penetrate narrow openings to reach a corpse indoors and in concealed environments.9 Scuttle flies are considered as insects of forensic importance and their presence on human corpse can be a very important indicator to determine PMImin.10–12 The role of scuttle flies in forensic investigation has been reviewed13 which includes the wellknown tramp species, Megaselia scalaris (Loew)10,11,14 and the ‘‘coffin fly” Conicera tibialis (Schmitz).15,16 In Malaysia, scuttle flies have been featured in forensic cases17 and they are considered as a ‘frequent and dominant’ indoor group of insects.18 Discoveries on different species of forensically important scuttle flies recorded in Malaysia and worldwide reveal there are more species likely to be found on human or animal remains.19–25 This consequently generates interest to further study the bionomics of scuttle flies in forensic entomology, particularly during decomposition process. Furthermore, there are frequent reports of human death cases indoors but only a few studies have been done to demonstrate decomposition and succession of scuttle flies in such environments. For this reason, we designed an indoor decomposition study to record and observe succession of scuttle flies that are likely to feature in human decomposition. 2. Materials & methods Two male white rabbit carcasses (Oryctolagus cuniculus), each weighing 2.44 and 2.88 kg, were used in this study. They were supplied by the Laboratory Animal Resource Unit, Faculty of Medicine Universiti Kebangsaan Malaysia (UKM) and euthanized by administering lethal injection of pentobarbital drug (0.1 ml/g) (UKM Animal Ethics Committee Reference: FSK/FRSIC/2011/NOOR&ZUHA/16-NOVEMBER/404-NO VEMBER-2011-NOVEMBER-2012-AR-CAT2). This study was conducted at Forensic Science Simulation Site, Faculty of Health Sciences UKM Bangi, Selangor (2.91°N, 101.79°E). It is an outdoor research facility adjacent to a secondary forest, consisting of a two-story portable cabin for general research purpose, a heavy-duty portable cabin for storage of field equipment and a smaller portable cabin used for indoor decomposition study. The cabin used in this research is 6.10 m (long) 3.05 m (wide) 2.50 m (wide) and raised approximately 0.30 m from the ground (Fig. 1A). It is fitted with an air-conditioning unit, a ventilation fan and a kitchen sink. The layout of the research to observe decomposition of rabbit carcass is shown in Fig. 1B. During each study period, daily room temperature was maintained by the air-conditioning unit
R.M. Zuha et al.
Figure 1 Decomposition study by simulating indoor environment. (A) The portable cabin was used for decomposition study for the first time. (B) The placement of rabbit carcass inside the portable cabin.
at 25.0 °C from 0700 h to 1900 h and the ventilation fan was switched-on. A layer of transparent plastic film was used to protect the cabin floor from damage and filth due to animal decomposition. Two layers of mesh fabric were fitted to the door as cover to avoid contamination of insects entering the cabin during sampling. There were two rounds of study, each with a duration of 40 days. The first round was conducted from 4 October 2010 to 13 November 2010 and the second round from 13 December 2010 to 22 January 2011. In each round, the rabbit carcass was put on a wire-mesh platform to facilitate weight measurement and placed at the center of the cabin. Temperature and humidity data loggers were placed inside and outside cabin to record the meteorological data. A temperature data logger attached with a probe was inserted into the carcass anus to measure its internal body temperature. Samplings were carried out daily during the first 11 days, every alternate day from 11th day until 27th day and every two days from 27th day until 40th day. Adult scuttle flies were aspirated directly from the carcass and preserved in 70% ethanol. Larvae and pupae, presumably of scuttle flies were reared until adult to determine their identities. Adult scuttle flies were processed on slides to facilitate identification26 and a few sample replicates were brought by the first author to the third
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
Indoor decomposition study of scuttle flies
3
author at Department of Zoology, University of Cambridge, UK, in November 2014 to validate identification of species. 3. Results 3.1. Environmental condition Outdoor ambient temperatures during each research period ranged between 26.8–33.0 °C (round 1) and 25.2–29.8 °C (round 2) while the relative humidity was 59.5–75.0% (round 1) and 72.5–95.0% (round 2). Inside the cabin, although the air-conditioner was maintained at 25.0 °C, the fluctuation of temperature was observed. The ranges were recorded as 24.0–31.0 °C (round 1) and 21.1–24.2 °C (round 2) while the range of relative humidity was 67.0–92.0% (round 1). Relative humidity for indoors in round 2 was not recorded because of
malfunctioning hygrometer. The temperature gradients of the cabin ambience and carcasses (rectal temperature) are shown in Fig. 2. The fluctuations were mostly inconsistent during round 1 study but temperatures were steadier in round 2. We found out there were a few disruptions of electrical supply to the cabin during round 1 causing the indoor temperature increase on certain days. In round 2, we managed to record larval masses activity which was not observed in round 1 during day 7–12. 3.2. Post-mortem changes For both rounds, there were four observable stages of decomposition recorded, i.e. fresh, bloated, active decay and postdecay. The duration for each decomposition stage in round 1 is as following (Table 1): fresh (day 1), bloated (day 2–3),
Round 1 32 30
Temperature (ºC)
28 26 24 22 20 1
3
5
7
9
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Day
Round 2 30
Temperature (ºC)
28
26
24
22
20 1
3
5
7
9
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Day
Figure 2 Average daily temperature of indoor (cabin), internal body and larval mass for both rounds (±0.1 °C). All data were recorded continuously (hourly). Larval mass temperatures in round 2 were recorded from day 7 to 10 and on day 12.
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
4
R.M. Zuha et al. Table 1
Faunal succession of scuttle fly and other sarcosaprophagous insect specimens on the rabbit carcass in round 1 study.
Key: F = fresh, B = bloat.
active decay (day 4–11) and post-decay (day 12–40). Similar durations were observed in round 2 (Table 2) except active decay stage was shorter (day 4–7) and post-decay stage was longer (day 8–40). It was difficult to discriminate the stages of decomposition especially during active and post-decay stage because of the slower rate of decomposition and rapid desiccation of the bodily fluid. Active decay stage was indicated by the onset on body flattening and pungent smell emanating from the body. Bodily fluid, resulting from the mixture of blood and decomposed internal tissues, was observed flushing out from the orifices during this stage but dried out within a couple of days. The eye soft tissues were also decayed and ruptured. During post-decay stage, the body became drier, less pungent and flattened. The hairs were loosened and dispersed on the floor. Similar features were observed until the last day of study, i.e. day 40. Overall, the weights of the carcass during the last day were reduced to approximately 54.9% (round 1) and 70.5% (round 2) from the fresh stage dead body weight. 3.3. Insect activity In the first round, M. scalaris was the dominant species and observed throughout the entire research period (Table 1).
Table 2
The earliest arrival of female M. scalaris (Fig. 3) was recorded at 1820 h, approximately 2 h after placement of the carcass. On the following day, a small dipteran larvae (<1.0 mm) was obtained from the bloody nasal cavity and reared which were later identified as male M. scalaris. Dipteran larvae were not seen around the carcass until day 3. Beginning day 7, post feeding phorid larvae were observed underneath the carcass. The first pupa was also detected on day 7, found on hairs underneath the carcass. Based on general observation, phorids larvae were not detected on the carrion’s body surface. Adult female Dohrniphora cornuta (Bigot) (Fig. 4) were found on day 6, 9 and 10 (during active decay stage). A single male Megaselia spiracularis (Schmitz) (Fig. 5) was found on day 6. The presence of blow fly Chrysomya megacephala (Fabricius) was delayed. The second instar larvae were collected on day 7 and its third instar larvae were found until day 11. Similar to the phorids, the majority of the larvae were found concentrated underneath the carcass. Although there are similar amounts of larvae and pupae to the phorids, the only female C. megacephala adult was detected near the cabin ceiling on day 8, indicating it could gain access to the cabin. After reviewing the access to the cabin, the blowfly was found entering the cabin via a small gap measuring approximately
Faunal succession of scuttle fly and other sarcosaprophagous insect specimens on the rabbit carcass in round 2 study.
Key: F = fresh, B = bloat.
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
Indoor decomposition study of scuttle flies
5
Figure 3 Megaselia scalaris. Female adult (left) and male adult (right). Bar = 1.0 mm.
Figure 5 Figure 4
Female adult Dohrniphora cornuta. Bar = 1.0 mm.
0.5 cm lining the window panes. Piophilidae larvae were also detected approximately 1.5 m from the carcass and only found on day 13. Ants were present and observed feeding on the dry bodily fluid on day 10. On day 13, we noticed C. megacephala pupae on the floor were removed by some of the ants. In the second round, scuttle flies were present but with lower density compared to C. megacephala which was more dominant during this period (Table 2). Adult M. scalaris was detected on day 4 and its pupae were found on the body on day 8. Larvae were unnoticeable until day 9. In contrast to the first round, there was a gap when the phorids were absent in a long period of time from day 15. Adult M. scalaris and M. spiracularis were found on day 28. C. megacephala larvae were the longest surviving fauna on the carcass and they were found from day 4 to 22. Species variation was also differed in this round with the presence of adult Ophyra spinigera Stein (Diptera: Muscidae) on day 5, 8, 10–12. Sarcophagidae (unidentified species) adult were found on day 7 and Piophila casei (Linnaeus) (Diptera: Piophilidae) larvae were collected on day 11–12. An adult Sepsidae (unidentified species) was also collected on day 8 and a Staphylinidae (unidentified species) beetle was detected on day 16. In both rounds, phorid pupae dispersal was approximately 50 cm from the center of the carcass. There were a few phorid pupae found on the carcass and hidden underneath the body. Pupae of C. megacephala were found to disperse further than
Male adult Megaselia spiracularis. Bar = 0.5 mm.
the phorids and were detected as far as to the side of the cabin’s wall. 4. Discussion There were three scuttle fly species recorded in this study from both rounds, i.e. M. scalaris, M. spiracularis and D. cornuta. During the first round of study, M. scalaris was found to be the dominant fly species and the earliest to reach carcass. Based on its life cycle on carcass, development of this species from larval stage until pupa was approximately 5 days, almost equivalent to total developmental time in a laboratory colony at 25 °C (4.1 days).27 M. scalaris is a common cosmopolitan species and widely reported in indoor cases.9,10,17,28 In the absence of other sarcosaprophagous species, M. scalaris can be a sole indicator to estimate minimum PMI.10,11 Another forensically important species, M. spiracularis was also observed on the carcasses but the occurrence was rare, i.e. day 6 (round 1) and day 28 (round 2). On both occasions, only male adults were captured from the carcasses. M. spiracularis has been featured in forensic cases in Malaysia indoors17,18 but the current developmental data available are the pupae development.29 At present, the distribution of this species includes Japan, Malaysia, Taiwan,30 China31 and New Zealand.32 In this study, M. spiracularis and M. scalaris were found coexisting indoors, similar to the report from the Northeast China.31 D. cornuta is also a cosmopolitan species and has been reported attracted to decaying organic materials including
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
6 mollusks, insects and decomposing vertebrates.33–35 In forensic cases, this species has been reported colonizing human remains located indoors and in buried environment20. From earlier studies, Dohrniphora species are major decomposers of animal remains. For example, D. incisuralis (Loew) larvae were found on buried pigs from bloat to post decay stage,36 and found even on animal carcasses in an open environment.37,38 In this study, the occurrence of D. cornuta was only observed in the first round during active decay stage and there were no larvae or pupae of this species recovered from the carcass. However, this finding is a new record from animal carcass in Malaysia and further indicates that D. cornuta is a potential forensically important species found indoors. There were four decomposition stages of rabbit carcasses in the cabin i.e. fresh, bloated, active decay and post decay The arrival of scuttle flies to the carcasses was observed during fresh stage (round 1) and active decay stage (round 2) but their occurrences according to developmental stages were not in sequential order. This is different with the occurrence of C. megacephala that could be observed sequentially, beginning from the 2nd instar larvae found on day 7 (active decay stage) to 3rd instar larvae on day 8 (active decay stage) and pupa on day 12 (post-decay stage). A similar pattern was observed in round 2 with the 2nd instar larvae found on day 4 (active decay stage), 3rd instar larvae on day 5 (active decay stage) and pupae on day 16 (post decay stage). Compared to previous indoor decomposition studies conducted in the similar tropical region, there are no records indicating the presence of scuttle flies. Nazni et al.39 made an observation for 86 days on decomposing monkey carcasses inside a wooden-brick hut, recorded 11 species of dipterans consisting of Calliphoridae, Muscidae, Stratiomyidae and Sarcophagidae but none of the specimens were identified as Phoridae. This probably suggests that the presence of specific sarcosaprophagous insects on carcasses placed indoors depends on how the human created environment was made.8 In few other documented cases, species of blow flies are the dominant insects on human remains and animal carcasses inside human dwellings4,7,8 but in few other occasions, blow flies and other sarcosaprophagous dipterans coexisted with scuttle flies on human remains indoors.9,18 Characteristics of faunal successions were inconsistent in round 1 and 2. In round 1, scuttle flies were the dominant insects indoor, accompanied by C. megacephala. There was a limited occurrence of P. casei larvae which are known associated in human decompositions,40 including from this region.41,42 In round 2, species diversity was increased whereby O. spinigera, Sarcophagidae, Sepsidae and Staphylinid beetles were added to the list. Ophyra spinigera, Sarcophagidae and Staphylinid have been recorded from indoor forensic cases and indoor succession studies in Malaysia.18,39 The presence of the only Sepsidae on day 7 would serve as interest for further study as this group is forensically important species indoors.43,44 In round 2, there was also a delay in the arrival of insects when the first scuttle fly detected on day 4, accompanied by the presence of C. megacephala 2nd instar larvae. On the increased species diversity on carcasses in round 2, there were a few possibilities that could cause such differences such as: (i) the first round study somehow altered the indoor environment and led to the increment of insect species attracted to the carcass in round 2, (ii) decompositions of animal carcasses were influenced by the changes of the temperatures and humidity inside cabin, and
R.M. Zuha et al. (iii) seasonality presence of sarcosaprophagous insects at research site. However, based on the current findings, the association between environmental conditions, faunal abundance and decomposition stages require further tests. 5. Conclusions Using succession analysis obtained from the first study conducted in the cabin, scuttle flies can be reliable and primary indicators to estimate PMImin. However, in the increased presence of other dipterans, they may be relegated to secondary role. This study also further highlighted M. scalaris, M. spiracularis and D. cornuta scuttle fly species of forensic importance for indoor cases in Malaysia. Funding School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, UKM. Conflict of interest None declared. Informed consent None declared. Ethical approval Necessary ethical approval was obtained from the institute ethics committee. UKM Animal Ethics Committee Reference: FSK/FRSIC/2011/NOOR&ZUHA/16NOVEMBER/404-NOVEMBER-2011-NOVEMBER-2012-A R-CAT2. Acknowledgments Authors are grateful to the laboratory staff of Forensic Science Program, School of Diagnostics and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia. We appreciate the help from Mr. See Huong Wen for helping us to prepare the research location and sampling method. The first author’s learning visit to the Department of Zoology, University of Cambridge, UK was supported by Young Researcher Incentive Grant GGPM-2014-018. The third author’s studies of Phoridae are currently supported by a grant from the Balfour-Browne Trust Fund (University of Cambridge). References 1. Early M, Goff ML. Arthropod succession patterns in exposed carrion on the island of O’ahu, Hawaiian Islands, USA. J Med Entomol 1986;23:520–31. 2. Goff ML, Omori AI, Gunatilake K. Estimation of postmortem interval by arthropod succession. Three case studies from the Hawaiian Islands. Am J Forensic Med Pathol 1988;9(3):220–5.
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
Indoor decomposition study of scuttle flies 3. Anderson GS. Insect succession on carrion and its relationship to determining time of death. In: Byrd JH, Castner JL, editors. Forensic entomology: the utility of arthropods in legal investigations. 1st ed. Boca Raton: CRC Press; 2001. p. 143–75. 4. Anderson GS. Comparison of decomposition rates and faunal colonization of carrion in indoor and outdoor environments. J Forensic Sci 2011;56(1):136–42. 5. Campobasso CP, Di Vella G, Introna F. Factors affecting decomposition and Diptera colonization. Forensic Sci Int 2001;120:18–27. 6. Mann RW, Bass WM, Meadows L. Time since death and decomposition of the human body: variables and observations in case and experimental field studies. J Forensic Sci 1990;35(1): 103–11. 7. Reibe S, Madea B. How promptly do blowflies colonise fresh carcasses? A study comparing indoor with outdoor locations. Forensic Sci Int 2010;195:52–7. 8. Pohjoisma¨ki JLO, Karhunen PJ, Goebeler S, Saukko P, Sa¨a¨ksja¨rvi IE. Indoors forensic entomology: colonization of human remains in closed environments by specific species of sarcosaprophagous flies. Forensic Sci Int 2010;199:38–42. 9. Bugelli V, Forni D, Alessandro Bassi L, Di Paolo M, Marra D, Lenzi S, et al. Forensic entomology and the estimation of the minimum time since death in indoor cases. J Forensic Sci 2015;60(2): 525–31. 10. Reibe S, Madea B. Use of Megaselia scalaris (Diptera: Phoridae) for post-mortem interval estimation indoors. Parasitol Res 2010;106:637–40. 11. Campobasso CP, Disney RHL, Introna F. A case of Megaselia scalaris (Loew) (Dipt., Phoridae) breeding in a human corpse. Aggrawal’s Internet J Forensic Med Toxicol 2004;5(1):3–5. 12. Goff ML. Comparison of insect species associated with decomposing remains recovered inside dwellings and outdoors on the island of Oahu, Hawaii. J Forensic Sci 1991;36:748–53. 13. Disney RHL. Scuttle flies: the Phoridae. London: Chapman & Hall; 1994. 14. Dewaele P, Leclercq M, Disney RHL. Entomologie et me´decine le´gale: les Phorides (Dipte´res) sur cadavres humains. Observation ine`dite. J Med Leg Droit Med 2000;43:569–72. 15. Martin-Vega D, Gomez-Gomez A, Baz A. The ‘‘coffin fly” Conicera tibialis (Diptera: Phoridae) breeding on buried human remains after a postmortem interval of 18 years. J Forensic Sci 2011;56(6):1654–6. 16. Leclercq M. Entomologie et medecine legale importance des Phorides (Dipteres) sur cadavres humains. Ann Soc Entomol Fr 1999;35(Suppl.):566–8. 17. Thevan K, Disney RHL, Ahmad AH. First records of two species of Oriental scuttle flies (Diptera: Phoridae) from forensic cases. Forensic Sci Int 2010;195:e5–7. 18. Kumara TK, Disney RHL, Abu Hassan A, Flores M, Tan SH, Mohamed Z, et al. Occurrence of oriental flies associated with indoor and outdoor human remains in the tropical climate of north Malaysia. J Vector Ecol 2012;37(1):62–8. 19. Zuha RM, See HW, Disney RHL, Omar B. First record of genus Puliciphora Dahl (Diptera: Phoridae) associated with rabbit carcasses placed in concealed environments in Malaysia. Forensic Sci Int 2014;245:e36–7. 20. Disney RHL, Garcia-Rojo A, Lindstro¨m A, Manlove JD. Further occurrences of Dohrniphora cornuta (Bigot) (Diptera, Phoridae) in forensic cases indicate likely importance of this species in future cases. Forensic Sci Int 2014;241:e20–2. 21. Manlove JD, Disney RHL. The use of Megaselia abdita (Diptera: Phoridae) in forensic entomology. Forensic Sci Int 2008;175:83–4. 22. Disney RHL, Manlove JD. First report of Triphleba nudipalpis (Becker) (Diptera: Phoridae) in a forensic case. Forensic Sci Int 2009;191:e1–3.
7 23. Disney RHL, Manlove JD. First occurrences of the Phorid, Megaselia abdita, in forensic cases in Britain. Med Vet Entomol 2005;19:489–91. 24. Garcı´ a-Rojo AM, Martı´ nez-Sa´nchez A, Lo´pez R, de la Vega M, Rica M, Gonza´lez M, et al. A mathematical model applied for assisting the estimation of PMI in a case of forensic importance. First record of Conicera similis (Diptera: Phoridae) in a corpse. Forensic Sci Int 2013;231:e11–8. 25. Bourel B, Tournel G, He´douin V, Gosset D. Entomofauna of buried bodies in northern France. Int J Legal Med 2004;118:215–20. 26. Disney RHL. The preservation of small Diptera. Entomol Mon Mag 2001;137:155–9. 27. Zuha RM, Omar B. Developmental rate, size, and sexual dimorphism of Megaselia scalaris (Loew) (Diptera: Phoridae): its possible implications in forensic entomology. Parasitol Res 2014;113(6):2285–94. 28. Greenberg B, Wells JD. Forensic use of Megaselia abdita and M. scalaris (Phoridae: Diptera): case studies, development rates, and egg structure. J Med Entomol 1998;35:205–9. 29. Feng DX, Liu GC. Pupal age estimation of forensically important Megaselia spiracularis Schmitz (Diptera: Phoridae). Forensic Sci Int 2013;231:199–203. 30. Borgmeier T. Studies on Indo-Australian phorid flies, based mainly on material of the Museum of Comparative Zoology and the United States National Museum (Diptera, Phoridae). Stud Entomol 1966;9:129–328. 31. Feng DX, Liu GC. Morphology of immature stages of Megaselia spiracularis Schmitz (Diptera: Phoridae). Microsc Res Tech 2012;75(9):1297–303. 32. Brown BV, Oliver H. First records of Megaselia scalaris (Loew) and M. spiracularis Schmitz (Diptera: Phoridae) from New Zealand, with additional information on other worldwide species. NZ Entomol 2007;30:85–7. 33. Bohart GE, Gressitt JL. Filth-inhabiting flies of Guam. Bernice P Bishop Mus Bull 1951;204:1–152. 34. Barnes JK. Life history of Dohrniphora cornuta (Bigot) (Diptera: Phoridae), a filth-inhabiting humpbacked fly. J NY Entomol Soc 1990;98(4):474–83. 35. Mitsui H, Nakayama H. Seasonal occurrence of phorid flies (Diptera) attracted to rotten flesh in and near Tokyo. Med Entomol Zool 2012;63(3):205–8. 36. Payne JA, King EW, Beinhart G. Arthropod succession and decomposition of buried pigs. Nature 1968;219(5159):1180–1. 37. Martinez E, Duque P, Wolff M. Succession pattern of carrionfeeding insects in Paramo, Colombia. Forensic Sci Int 2007;166:182–9. 38. Vela´squez Y, Magan˜a C, Martı´ nez-Sa´nchez A, Rojo S. Diptera of forensic importance in the Iberian Peninsula: larval identification key. Med Vet Entomol 2010;24:293–308. 39. Nazni WA, Lee HL, Chen CD, Heo CC, Abdullah AG, Wan Norjuliana WM, et al. Comparative insect fauna succession on indoor and outdoor monkey carrions in a semi-forested area in Malaysia. Asian Pac J Trop Biomed 2011;S232–8. 40. Martı´ n-Vega D. Skipping clues: forensic importance of the family Piophilidae (Diptera). Forensic Sci Int 2011;212:1–5. 41. Sukontason K, Vichairat K, Piangjai S, Lertthamnongtham S, Vogtsberger RC, Olson JK. The first documented forensic entomology case in Thailand. J Med Entomol 2001;38(5):746–8. 42. Nazni WA, Jeffery J, Sa’diyah I, Chen CD, Rohayu SA, et al. First report of maggots of family Piophilidae recovered from human cadavers in Malaysia. Trop Biomed 2008;25(2):173–5. 43. de Carvalho CJB, de Mello-Patiu CA. Key to the adults of the most common forensic species of Diptera in South America. Rev Bras Entomol 2008;52(3):390–406. 44. Ahmad A, Ahmad AH. A preliminary study on the decomposition and dipteran associated with exposed carcasses in an oil palm
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
H O S T E D BY
Contents lists available at ScienceDirect
Egyptian Journal of Forensic Sciences journal homepage: http://www.journals.elsevier.com/egyptian-journal-of-forensic-sciences
Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae) Raja M. Zuha a,*, Sheril June Ankasha b, R. Henry L. Disney c, Baharudin Omar b a Forensic Science Program, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia b Biomedical Science Program, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia c Department of Zoology, University of Cambridge, Downing St, Cambridge CB2 3EJ, United Kingdom
Received 29 May 2015; revised 10 August 2015; accepted 6 September 2015
KEYWORDS Decomposition; Indoors; PMI; Scuttle flies; Phoridae
Abstract Scuttle flies (Diptera: Phoridae) are a diversified insect group of forensic importance. Their frequent presence on human corpses indoors and in concealed environments can be the sole indicators to estimate the minimum post mortem interval (PMImin). However, bionomics of scuttle flies on decomposing animal carcasses are rarely documented indoors. The objective of this research is to observe and document the occurrence of scuttle flies on decomposing animal carcass placed inside a portable cabin maintained at room temperature (25.0 °C) in Bangi, Malaysia. This study was conducted in two rounds for a period of 40-day each and samplings were carried out in different intervals. Adult scuttle flies were aspirated directly from the carcass and preserved in 70% ethanol. Their larvae and pupae were reared until adult stage to facilitate identification. Megaselia scalaris (Loew), Megaselia spiracularis (Schmitz) and Dohrniphora cornuta (Bigot) were the scuttle flies found on the carcasses with M. scalaris being the earliest and dominant to colonize the body. This cosmopolitan species proved to be the best indicator to estimate PMImin indoor but in the increased presence of other fly species, it might be relegated to a secondary role. The scuttle flies were also found to coexist with other dipterans of forensic importance in an indoor environment, mainly Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae). This information expands the knowledge on the bionomics of scuttle flies on decomposing animal remains indoors. Ó 2015 Hosting by Elsevier B.V. on behalf of The International Association of Law and Forensic Sciences (IALFS).
* Corresponding author. Tel.: +60 193930366, office: +60 389214833. E-mail address: [email protected] (R.M. Zuha). Peer review under responsibility of The International Association of Law and Forensic Sciences (IALFS).
1. Introduction In forensic entomology, decomposition study helps to identify insects of forensic importance and estimate the minimum post mortem interval (PMImin). By using animal carcasses as
http://dx.doi.org/10.1016/j.ejfs.2015.09.002 2090-536X Ó 2015 Hosting by Elsevier B.V. on behalf of The International Association of Law and Forensic Sciences (IALFS). Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
2 decomposition models, the ecological relationship between insects and decaying human remains can be demonstrated.1,2 Succession analysis from the predictable sequence of carrionvisiting insects systematically tabulates the occurrence of insects in various conditions such as in natural outdoor or human-made indoor environments, and this information is very useful in forensic investigations.3,4 Indoor environments usually limit the presence of blow flies, or at least, delay their arrival to the human remains.5 When investigating PMImin of corpses found indoors, access to the body by insects is one of the many crucial factors that affect decomposition rate.6 In the context of forensic entomology, the earliest sarcosaprophagous insect that could gain entry to colonize corpse indoors can be the primary indicator for PMI estimation.7,8 This often refers to the diminutive scuttle flies (Diptera: Phoridae) that can penetrate narrow openings to reach a corpse indoors and in concealed environments.9 Scuttle flies are considered as insects of forensic importance and their presence on human corpse can be a very important indicator to determine PMImin.10–12 The role of scuttle flies in forensic investigation has been reviewed13 which includes the wellknown tramp species, Megaselia scalaris (Loew)10,11,14 and the ‘‘coffin fly” Conicera tibialis (Schmitz).15,16 In Malaysia, scuttle flies have been featured in forensic cases17 and they are considered as a ‘frequent and dominant’ indoor group of insects.18 Discoveries on different species of forensically important scuttle flies recorded in Malaysia and worldwide reveal there are more species likely to be found on human or animal remains.19–25 This consequently generates interest to further study the bionomics of scuttle flies in forensic entomology, particularly during decomposition process. Furthermore, there are frequent reports of human death cases indoors but only a few studies have been done to demonstrate decomposition and succession of scuttle flies in such environments. For this reason, we designed an indoor decomposition study to record and observe succession of scuttle flies that are likely to feature in human decomposition. 2. Materials & methods Two male white rabbit carcasses (Oryctolagus cuniculus), each weighing 2.44 and 2.88 kg, were used in this study. They were supplied by the Laboratory Animal Resource Unit, Faculty of Medicine Universiti Kebangsaan Malaysia (UKM) and euthanized by administering lethal injection of pentobarbital drug (0.1 ml/g) (UKM Animal Ethics Committee Reference: FSK/FRSIC/2011/NOOR&ZUHA/16-NOVEMBER/404-NO VEMBER-2011-NOVEMBER-2012-AR-CAT2). This study was conducted at Forensic Science Simulation Site, Faculty of Health Sciences UKM Bangi, Selangor (2.91°N, 101.79°E). It is an outdoor research facility adjacent to a secondary forest, consisting of a two-story portable cabin for general research purpose, a heavy-duty portable cabin for storage of field equipment and a smaller portable cabin used for indoor decomposition study. The cabin used in this research is 6.10 m (long) 3.05 m (wide) 2.50 m (wide) and raised approximately 0.30 m from the ground (Fig. 1A). It is fitted with an air-conditioning unit, a ventilation fan and a kitchen sink. The layout of the research to observe decomposition of rabbit carcass is shown in Fig. 1B. During each study period, daily room temperature was maintained by the air-conditioning unit
R.M. Zuha et al.
Figure 1 Decomposition study by simulating indoor environment. (A) The portable cabin was used for decomposition study for the first time. (B) The placement of rabbit carcass inside the portable cabin.
at 25.0 °C from 0700 h to 1900 h and the ventilation fan was switched-on. A layer of transparent plastic film was used to protect the cabin floor from damage and filth due to animal decomposition. Two layers of mesh fabric were fitted to the door as cover to avoid contamination of insects entering the cabin during sampling. There were two rounds of study, each with a duration of 40 days. The first round was conducted from 4 October 2010 to 13 November 2010 and the second round from 13 December 2010 to 22 January 2011. In each round, the rabbit carcass was put on a wire-mesh platform to facilitate weight measurement and placed at the center of the cabin. Temperature and humidity data loggers were placed inside and outside cabin to record the meteorological data. A temperature data logger attached with a probe was inserted into the carcass anus to measure its internal body temperature. Samplings were carried out daily during the first 11 days, every alternate day from 11th day until 27th day and every two days from 27th day until 40th day. Adult scuttle flies were aspirated directly from the carcass and preserved in 70% ethanol. Larvae and pupae, presumably of scuttle flies were reared until adult to determine their identities. Adult scuttle flies were processed on slides to facilitate identification26 and a few sample replicates were brought by the first author to the third
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
Indoor decomposition study of scuttle flies
3
author at Department of Zoology, University of Cambridge, UK, in November 2014 to validate identification of species. 3. Results 3.1. Environmental condition Outdoor ambient temperatures during each research period ranged between 26.8–33.0 °C (round 1) and 25.2–29.8 °C (round 2) while the relative humidity was 59.5–75.0% (round 1) and 72.5–95.0% (round 2). Inside the cabin, although the air-conditioner was maintained at 25.0 °C, the fluctuation of temperature was observed. The ranges were recorded as 24.0–31.0 °C (round 1) and 21.1–24.2 °C (round 2) while the range of relative humidity was 67.0–92.0% (round 1). Relative humidity for indoors in round 2 was not recorded because of
malfunctioning hygrometer. The temperature gradients of the cabin ambience and carcasses (rectal temperature) are shown in Fig. 2. The fluctuations were mostly inconsistent during round 1 study but temperatures were steadier in round 2. We found out there were a few disruptions of electrical supply to the cabin during round 1 causing the indoor temperature increase on certain days. In round 2, we managed to record larval masses activity which was not observed in round 1 during day 7–12. 3.2. Post-mortem changes For both rounds, there were four observable stages of decomposition recorded, i.e. fresh, bloated, active decay and postdecay. The duration for each decomposition stage in round 1 is as following (Table 1): fresh (day 1), bloated (day 2–3),
Round 1 32 30
Temperature (ºC)
28 26 24 22 20 1
3
5
7
9
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Day
Round 2 30
Temperature (ºC)
28
26
24
22
20 1
3
5
7
9
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Day
Figure 2 Average daily temperature of indoor (cabin), internal body and larval mass for both rounds (±0.1 °C). All data were recorded continuously (hourly). Larval mass temperatures in round 2 were recorded from day 7 to 10 and on day 12.
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
4
R.M. Zuha et al. Table 1
Faunal succession of scuttle fly and other sarcosaprophagous insect specimens on the rabbit carcass in round 1 study.
Key: F = fresh, B = bloat.
active decay (day 4–11) and post-decay (day 12–40). Similar durations were observed in round 2 (Table 2) except active decay stage was shorter (day 4–7) and post-decay stage was longer (day 8–40). It was difficult to discriminate the stages of decomposition especially during active and post-decay stage because of the slower rate of decomposition and rapid desiccation of the bodily fluid. Active decay stage was indicated by the onset on body flattening and pungent smell emanating from the body. Bodily fluid, resulting from the mixture of blood and decomposed internal tissues, was observed flushing out from the orifices during this stage but dried out within a couple of days. The eye soft tissues were also decayed and ruptured. During post-decay stage, the body became drier, less pungent and flattened. The hairs were loosened and dispersed on the floor. Similar features were observed until the last day of study, i.e. day 40. Overall, the weights of the carcass during the last day were reduced to approximately 54.9% (round 1) and 70.5% (round 2) from the fresh stage dead body weight. 3.3. Insect activity In the first round, M. scalaris was the dominant species and observed throughout the entire research period (Table 1).
Table 2
The earliest arrival of female M. scalaris (Fig. 3) was recorded at 1820 h, approximately 2 h after placement of the carcass. On the following day, a small dipteran larvae (<1.0 mm) was obtained from the bloody nasal cavity and reared which were later identified as male M. scalaris. Dipteran larvae were not seen around the carcass until day 3. Beginning day 7, post feeding phorid larvae were observed underneath the carcass. The first pupa was also detected on day 7, found on hairs underneath the carcass. Based on general observation, phorids larvae were not detected on the carrion’s body surface. Adult female Dohrniphora cornuta (Bigot) (Fig. 4) were found on day 6, 9 and 10 (during active decay stage). A single male Megaselia spiracularis (Schmitz) (Fig. 5) was found on day 6. The presence of blow fly Chrysomya megacephala (Fabricius) was delayed. The second instar larvae were collected on day 7 and its third instar larvae were found until day 11. Similar to the phorids, the majority of the larvae were found concentrated underneath the carcass. Although there are similar amounts of larvae and pupae to the phorids, the only female C. megacephala adult was detected near the cabin ceiling on day 8, indicating it could gain access to the cabin. After reviewing the access to the cabin, the blowfly was found entering the cabin via a small gap measuring approximately
Faunal succession of scuttle fly and other sarcosaprophagous insect specimens on the rabbit carcass in round 2 study.
Key: F = fresh, B = bloat.
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
Indoor decomposition study of scuttle flies
5
Figure 3 Megaselia scalaris. Female adult (left) and male adult (right). Bar = 1.0 mm.
Figure 5 Figure 4
Female adult Dohrniphora cornuta. Bar = 1.0 mm.
0.5 cm lining the window panes. Piophilidae larvae were also detected approximately 1.5 m from the carcass and only found on day 13. Ants were present and observed feeding on the dry bodily fluid on day 10. On day 13, we noticed C. megacephala pupae on the floor were removed by some of the ants. In the second round, scuttle flies were present but with lower density compared to C. megacephala which was more dominant during this period (Table 2). Adult M. scalaris was detected on day 4 and its pupae were found on the body on day 8. Larvae were unnoticeable until day 9. In contrast to the first round, there was a gap when the phorids were absent in a long period of time from day 15. Adult M. scalaris and M. spiracularis were found on day 28. C. megacephala larvae were the longest surviving fauna on the carcass and they were found from day 4 to 22. Species variation was also differed in this round with the presence of adult Ophyra spinigera Stein (Diptera: Muscidae) on day 5, 8, 10–12. Sarcophagidae (unidentified species) adult were found on day 7 and Piophila casei (Linnaeus) (Diptera: Piophilidae) larvae were collected on day 11–12. An adult Sepsidae (unidentified species) was also collected on day 8 and a Staphylinidae (unidentified species) beetle was detected on day 16. In both rounds, phorid pupae dispersal was approximately 50 cm from the center of the carcass. There were a few phorid pupae found on the carcass and hidden underneath the body. Pupae of C. megacephala were found to disperse further than
Male adult Megaselia spiracularis. Bar = 0.5 mm.
the phorids and were detected as far as to the side of the cabin’s wall. 4. Discussion There were three scuttle fly species recorded in this study from both rounds, i.e. M. scalaris, M. spiracularis and D. cornuta. During the first round of study, M. scalaris was found to be the dominant fly species and the earliest to reach carcass. Based on its life cycle on carcass, development of this species from larval stage until pupa was approximately 5 days, almost equivalent to total developmental time in a laboratory colony at 25 °C (4.1 days).27 M. scalaris is a common cosmopolitan species and widely reported in indoor cases.9,10,17,28 In the absence of other sarcosaprophagous species, M. scalaris can be a sole indicator to estimate minimum PMI.10,11 Another forensically important species, M. spiracularis was also observed on the carcasses but the occurrence was rare, i.e. day 6 (round 1) and day 28 (round 2). On both occasions, only male adults were captured from the carcasses. M. spiracularis has been featured in forensic cases in Malaysia indoors17,18 but the current developmental data available are the pupae development.29 At present, the distribution of this species includes Japan, Malaysia, Taiwan,30 China31 and New Zealand.32 In this study, M. spiracularis and M. scalaris were found coexisting indoors, similar to the report from the Northeast China.31 D. cornuta is also a cosmopolitan species and has been reported attracted to decaying organic materials including
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
6 mollusks, insects and decomposing vertebrates.33–35 In forensic cases, this species has been reported colonizing human remains located indoors and in buried environment20. From earlier studies, Dohrniphora species are major decomposers of animal remains. For example, D. incisuralis (Loew) larvae were found on buried pigs from bloat to post decay stage,36 and found even on animal carcasses in an open environment.37,38 In this study, the occurrence of D. cornuta was only observed in the first round during active decay stage and there were no larvae or pupae of this species recovered from the carcass. However, this finding is a new record from animal carcass in Malaysia and further indicates that D. cornuta is a potential forensically important species found indoors. There were four decomposition stages of rabbit carcasses in the cabin i.e. fresh, bloated, active decay and post decay The arrival of scuttle flies to the carcasses was observed during fresh stage (round 1) and active decay stage (round 2) but their occurrences according to developmental stages were not in sequential order. This is different with the occurrence of C. megacephala that could be observed sequentially, beginning from the 2nd instar larvae found on day 7 (active decay stage) to 3rd instar larvae on day 8 (active decay stage) and pupa on day 12 (post-decay stage). A similar pattern was observed in round 2 with the 2nd instar larvae found on day 4 (active decay stage), 3rd instar larvae on day 5 (active decay stage) and pupae on day 16 (post decay stage). Compared to previous indoor decomposition studies conducted in the similar tropical region, there are no records indicating the presence of scuttle flies. Nazni et al.39 made an observation for 86 days on decomposing monkey carcasses inside a wooden-brick hut, recorded 11 species of dipterans consisting of Calliphoridae, Muscidae, Stratiomyidae and Sarcophagidae but none of the specimens were identified as Phoridae. This probably suggests that the presence of specific sarcosaprophagous insects on carcasses placed indoors depends on how the human created environment was made.8 In few other documented cases, species of blow flies are the dominant insects on human remains and animal carcasses inside human dwellings4,7,8 but in few other occasions, blow flies and other sarcosaprophagous dipterans coexisted with scuttle flies on human remains indoors.9,18 Characteristics of faunal successions were inconsistent in round 1 and 2. In round 1, scuttle flies were the dominant insects indoor, accompanied by C. megacephala. There was a limited occurrence of P. casei larvae which are known associated in human decompositions,40 including from this region.41,42 In round 2, species diversity was increased whereby O. spinigera, Sarcophagidae, Sepsidae and Staphylinid beetles were added to the list. Ophyra spinigera, Sarcophagidae and Staphylinid have been recorded from indoor forensic cases and indoor succession studies in Malaysia.18,39 The presence of the only Sepsidae on day 7 would serve as interest for further study as this group is forensically important species indoors.43,44 In round 2, there was also a delay in the arrival of insects when the first scuttle fly detected on day 4, accompanied by the presence of C. megacephala 2nd instar larvae. On the increased species diversity on carcasses in round 2, there were a few possibilities that could cause such differences such as: (i) the first round study somehow altered the indoor environment and led to the increment of insect species attracted to the carcass in round 2, (ii) decompositions of animal carcasses were influenced by the changes of the temperatures and humidity inside cabin, and
R.M. Zuha et al. (iii) seasonality presence of sarcosaprophagous insects at research site. However, based on the current findings, the association between environmental conditions, faunal abundance and decomposition stages require further tests. 5. Conclusions Using succession analysis obtained from the first study conducted in the cabin, scuttle flies can be reliable and primary indicators to estimate PMImin. However, in the increased presence of other dipterans, they may be relegated to secondary role. This study also further highlighted M. scalaris, M. spiracularis and D. cornuta scuttle fly species of forensic importance for indoor cases in Malaysia. Funding School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, UKM. Conflict of interest None declared. Informed consent None declared. Ethical approval Necessary ethical approval was obtained from the institute ethics committee. UKM Animal Ethics Committee Reference: FSK/FRSIC/2011/NOOR&ZUHA/16NOVEMBER/404-NOVEMBER-2011-NOVEMBER-2012-A R-CAT2. Acknowledgments Authors are grateful to the laboratory staff of Forensic Science Program, School of Diagnostics and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia. We appreciate the help from Mr. See Huong Wen for helping us to prepare the research location and sampling method. The first author’s learning visit to the Department of Zoology, University of Cambridge, UK was supported by Young Researcher Incentive Grant GGPM-2014-018. The third author’s studies of Phoridae are currently supported by a grant from the Balfour-Browne Trust Fund (University of Cambridge). References 1. Early M, Goff ML. Arthropod succession patterns in exposed carrion on the island of O’ahu, Hawaiian Islands, USA. J Med Entomol 1986;23:520–31. 2. Goff ML, Omori AI, Gunatilake K. Estimation of postmortem interval by arthropod succession. Three case studies from the Hawaiian Islands. Am J Forensic Med Pathol 1988;9(3):220–5.
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002
Indoor decomposition study of scuttle flies 3. Anderson GS. Insect succession on carrion and its relationship to determining time of death. In: Byrd JH, Castner JL, editors. Forensic entomology: the utility of arthropods in legal investigations. 1st ed. Boca Raton: CRC Press; 2001. p. 143–75. 4. Anderson GS. Comparison of decomposition rates and faunal colonization of carrion in indoor and outdoor environments. J Forensic Sci 2011;56(1):136–42. 5. Campobasso CP, Di Vella G, Introna F. Factors affecting decomposition and Diptera colonization. Forensic Sci Int 2001;120:18–27. 6. Mann RW, Bass WM, Meadows L. Time since death and decomposition of the human body: variables and observations in case and experimental field studies. J Forensic Sci 1990;35(1): 103–11. 7. Reibe S, Madea B. How promptly do blowflies colonise fresh carcasses? A study comparing indoor with outdoor locations. Forensic Sci Int 2010;195:52–7. 8. Pohjoisma¨ki JLO, Karhunen PJ, Goebeler S, Saukko P, Sa¨a¨ksja¨rvi IE. Indoors forensic entomology: colonization of human remains in closed environments by specific species of sarcosaprophagous flies. Forensic Sci Int 2010;199:38–42. 9. Bugelli V, Forni D, Alessandro Bassi L, Di Paolo M, Marra D, Lenzi S, et al. Forensic entomology and the estimation of the minimum time since death in indoor cases. J Forensic Sci 2015;60(2): 525–31. 10. Reibe S, Madea B. Use of Megaselia scalaris (Diptera: Phoridae) for post-mortem interval estimation indoors. Parasitol Res 2010;106:637–40. 11. Campobasso CP, Disney RHL, Introna F. A case of Megaselia scalaris (Loew) (Dipt., Phoridae) breeding in a human corpse. Aggrawal’s Internet J Forensic Med Toxicol 2004;5(1):3–5. 12. Goff ML. Comparison of insect species associated with decomposing remains recovered inside dwellings and outdoors on the island of Oahu, Hawaii. J Forensic Sci 1991;36:748–53. 13. Disney RHL. Scuttle flies: the Phoridae. London: Chapman & Hall; 1994. 14. Dewaele P, Leclercq M, Disney RHL. Entomologie et me´decine le´gale: les Phorides (Dipte´res) sur cadavres humains. Observation ine`dite. J Med Leg Droit Med 2000;43:569–72. 15. Martin-Vega D, Gomez-Gomez A, Baz A. The ‘‘coffin fly” Conicera tibialis (Diptera: Phoridae) breeding on buried human remains after a postmortem interval of 18 years. J Forensic Sci 2011;56(6):1654–6. 16. Leclercq M. Entomologie et medecine legale importance des Phorides (Dipteres) sur cadavres humains. Ann Soc Entomol Fr 1999;35(Suppl.):566–8. 17. Thevan K, Disney RHL, Ahmad AH. First records of two species of Oriental scuttle flies (Diptera: Phoridae) from forensic cases. Forensic Sci Int 2010;195:e5–7. 18. Kumara TK, Disney RHL, Abu Hassan A, Flores M, Tan SH, Mohamed Z, et al. Occurrence of oriental flies associated with indoor and outdoor human remains in the tropical climate of north Malaysia. J Vector Ecol 2012;37(1):62–8. 19. Zuha RM, See HW, Disney RHL, Omar B. First record of genus Puliciphora Dahl (Diptera: Phoridae) associated with rabbit carcasses placed in concealed environments in Malaysia. Forensic Sci Int 2014;245:e36–7. 20. Disney RHL, Garcia-Rojo A, Lindstro¨m A, Manlove JD. Further occurrences of Dohrniphora cornuta (Bigot) (Diptera, Phoridae) in forensic cases indicate likely importance of this species in future cases. Forensic Sci Int 2014;241:e20–2. 21. Manlove JD, Disney RHL. The use of Megaselia abdita (Diptera: Phoridae) in forensic entomology. Forensic Sci Int 2008;175:83–4. 22. Disney RHL, Manlove JD. First report of Triphleba nudipalpis (Becker) (Diptera: Phoridae) in a forensic case. Forensic Sci Int 2009;191:e1–3.
7 23. Disney RHL, Manlove JD. First occurrences of the Phorid, Megaselia abdita, in forensic cases in Britain. Med Vet Entomol 2005;19:489–91. 24. Garcı´ a-Rojo AM, Martı´ nez-Sa´nchez A, Lo´pez R, de la Vega M, Rica M, Gonza´lez M, et al. A mathematical model applied for assisting the estimation of PMI in a case of forensic importance. First record of Conicera similis (Diptera: Phoridae) in a corpse. Forensic Sci Int 2013;231:e11–8. 25. Bourel B, Tournel G, He´douin V, Gosset D. Entomofauna of buried bodies in northern France. Int J Legal Med 2004;118:215–20. 26. Disney RHL. The preservation of small Diptera. Entomol Mon Mag 2001;137:155–9. 27. Zuha RM, Omar B. Developmental rate, size, and sexual dimorphism of Megaselia scalaris (Loew) (Diptera: Phoridae): its possible implications in forensic entomology. Parasitol Res 2014;113(6):2285–94. 28. Greenberg B, Wells JD. Forensic use of Megaselia abdita and M. scalaris (Phoridae: Diptera): case studies, development rates, and egg structure. J Med Entomol 1998;35:205–9. 29. Feng DX, Liu GC. Pupal age estimation of forensically important Megaselia spiracularis Schmitz (Diptera: Phoridae). Forensic Sci Int 2013;231:199–203. 30. Borgmeier T. Studies on Indo-Australian phorid flies, based mainly on material of the Museum of Comparative Zoology and the United States National Museum (Diptera, Phoridae). Stud Entomol 1966;9:129–328. 31. Feng DX, Liu GC. Morphology of immature stages of Megaselia spiracularis Schmitz (Diptera: Phoridae). Microsc Res Tech 2012;75(9):1297–303. 32. Brown BV, Oliver H. First records of Megaselia scalaris (Loew) and M. spiracularis Schmitz (Diptera: Phoridae) from New Zealand, with additional information on other worldwide species. NZ Entomol 2007;30:85–7. 33. Bohart GE, Gressitt JL. Filth-inhabiting flies of Guam. Bernice P Bishop Mus Bull 1951;204:1–152. 34. Barnes JK. Life history of Dohrniphora cornuta (Bigot) (Diptera: Phoridae), a filth-inhabiting humpbacked fly. J NY Entomol Soc 1990;98(4):474–83. 35. Mitsui H, Nakayama H. Seasonal occurrence of phorid flies (Diptera) attracted to rotten flesh in and near Tokyo. Med Entomol Zool 2012;63(3):205–8. 36. Payne JA, King EW, Beinhart G. Arthropod succession and decomposition of buried pigs. Nature 1968;219(5159):1180–1. 37. Martinez E, Duque P, Wolff M. Succession pattern of carrionfeeding insects in Paramo, Colombia. Forensic Sci Int 2007;166:182–9. 38. Vela´squez Y, Magan˜a C, Martı´ nez-Sa´nchez A, Rojo S. Diptera of forensic importance in the Iberian Peninsula: larval identification key. Med Vet Entomol 2010;24:293–308. 39. Nazni WA, Lee HL, Chen CD, Heo CC, Abdullah AG, Wan Norjuliana WM, et al. Comparative insect fauna succession on indoor and outdoor monkey carrions in a semi-forested area in Malaysia. Asian Pac J Trop Biomed 2011;S232–8. 40. Martı´ n-Vega D. Skipping clues: forensic importance of the family Piophilidae (Diptera). Forensic Sci Int 2011;212:1–5. 41. Sukontason K, Vichairat K, Piangjai S, Lertthamnongtham S, Vogtsberger RC, Olson JK. The first documented forensic entomology case in Thailand. J Med Entomol 2001;38(5):746–8. 42. Nazni WA, Jeffery J, Sa’diyah I, Chen CD, Rohayu SA, et al. First report of maggots of family Piophilidae recovered from human cadavers in Malaysia. Trop Biomed 2008;25(2):173–5. 43. de Carvalho CJB, de Mello-Patiu CA. Key to the adults of the most common forensic species of Diptera in South America. Rev Bras Entomol 2008;52(3):390–406. 44. Ahmad A, Ahmad AH. A preliminary study on the decomposition and dipteran associated with exposed carcasses in an oil palm
Please cite this article in press as: Zuha RM et al. Indoor decomposition study in Malaysia with special reference to the scuttle flies (Diptera: Phoridae), Egypt J Forensic Sci (2015), http://dx.doi.org/10.1016/j.ejfs.2015.09.002