First record of Diamesus osculans (Vigors, 1825) (Coleoptera: Silphidae) colonization on a human corpse.

A partially skeletonized human corpse was found in bushes in Selangor, Malaysia in June 2020. Entomological evidence was collected during the autopsy and sent to the Department of Medical Microbiology and Parasitology, Faculty of Medicine, Universiti Teknologi MARA (UiTM) for minimum postmortem interval (PMImin) analysis. Standard protocols were applied when processing preserved and live insect specimens of both larval and pupal stages. Entomological evidence revealed that the corpse was colonized by Chrysomya nigripes Aubertin, 1932 (Diptera: Calliphoridae) and Diamesus osculans (Vigors, 1825) (Coleoptera: Silphidae). Chrysomya nigripes was chosen as the PMImin indicator as this fly species is an earlier colonizer compared to D. osculans beetle larvae which their presence is the indicative of late stage of decomposition. For the present case, the pupae of C. nigripes were the oldest insect evidence collected and based on the available developmental data, the estimated minimum PMI was established between 9 and 12 days. It is noteworthy to highlight that this is the first record of D. osculans colonization on a human corpse.

Machine learning analysis of wing venation patterns accurately identifies Sarcophagidae, Calliphoridae and Muscidae fly species.

In medical, veterinary and forensic entomology, the ease and affordability of image data acquisition have resulted in whole-image analysis becoming an invaluable approach for species identification. Krawtchouk moment invariants are a classical mathematical transformation that can extract local features from an image, thus allowing subtle species-specific biological variations to be accentuated for subsequent analyses. We extracted Krawtchouk moment invariant features from binarised wing images of 759 male fly specimens from the Calliphoridae, Sarcophagidae and Muscidae families (13 species and a species variant). Subsequently, we trained the Generalized, Unbiased, Interaction Detection and Estimation random forests classifier using linear discriminants derived from these features and inferred the species identity of specimens from the test samples. Fivefold cross-validation results show a 98.56 ± 0.38% (standard error) mean identification accuracy at the family level and a 91.04 ± 1.33% mean identification accuracy at the species level. The mean F1-score of 0.89 ± 0.02 reflects good balance of precision and recall properties of the model. The present study consolidates findings from previous small pilot studies of the usefulness of wing venation patterns for inferring species identities. Thus, the stage is set for the development of a mature data analytic ecosystem for routine computer image-based identification of fly species that are of medical, veterinary and forensic importance.

Reporting beetles in a mummified human corpse in Malaysia: Necrobia rufipes (Fabricius, 1781) (Coleoptera: Cleridae) and Dermestes maculatus De Geer, 1774 (Coleoptera: Dermestidae).

This case study reports on two unrecorded Coleopteran species found together on a human corpse in Malaysia. The mummified human remains were discovered in a house in Selangor, Malaysia. The pathologist confirmed that the death was due to a traumatic chest injury. Maggots, beetles, and fly pupal casings were found mainly on the front part of the body. Empty puparia of Diptera were collected during the autopsy and identified later as the muscid Synthesiomyia nudiseta (van der Wulp, 1883) (Diptera: Muscidae). Also, the insect evidence received included larvae and pupae of Megaselia sp. (Diptera: Phoridae). According to the insect development data, the minimum postmortem period was estimated by the time to reach the pupal developmental stage (in days). The entomological evidence included the first record of Dermestes maculatus De Geer, 1774 (Coleoptera: Dermestidae) and Necrobia rufipes (Fabricius, 1781) (Coleoptera: Cleridae), which have not previously been recorded on human remains in Malaysia.

Estimation of PMI for human remains wrapped in a blanket, with first report of Puliciphora rufipes (Phoridae) and Synthesiomyia nudiseta (Muscidae) outdoors in SE Spain.

The estimation of the minimum value of the postmortem interval is affected by well-known abiotic factors such as temperature and humidity, and others relating to the crime scene (e.g. the presence of direct sunlight or shade, immersion in water). However, there are few published data related to other variables that may exist, such as the presence of different insect species, wrapping of the body, or the presence or absence of maggot masses or predatory larvae. In this paper, a case report is presented in which the corpse of a homeless person was partially wrapped in a blanket. The corpse was found outdoors, in an open area in the province of Alicante (SE Spain). Empty puparia of different species of Diptera were collected during the autopsy. According to the insect development data, the minimum postmortem period was estimated and the influence of different factors, especially the effect of being wrapped in the blanket and the presence of the puparia of different species, was discussed. The entomological evidence includes the first record of Synthesiomyia nudiseta (van der Wulp, 1883) (Diptera: Muscidae) in outdoor conditions, and Puliciphora rufipes Silva Figueroa, 1916 (Diptera: Phoridae), which has not previously been recorded on human remains.

Coexistence and intraguild competition of Chrysomya albiceps and Lucilia sericata larvae: case reports and experimental studies applied to forensic entomology.

The larval development of Chrysomya albiceps and Lucilia sericata is a well-known and valuable tool for estimating the postmortem interval (PMI). The third instar larvae of Ch. albiceps are facultative predators of the larvae of other necrophagous dipterans, and this behaviour is undoubtedly an important factor to consider. Both species are found together during human autopsies in Spain and other parts of Europe, where they cohabit, so a precise knowledge of their larval coexistence data is essential. The aim of this study is to investigate their coexistence and the intraguild predation of Ch. albiceps on L. sericata under experimental conditions and in real case reports. To analyse intra- and interspecific competition, four densities were used under controlled abiotic conditions [25ºC, 60-70% RH and 12:12 (D:N)]. The experimental data were compared with data corresponding to their coexistence in natural conditions, so annual activity and forensic case reports for both species were studied. The results indicate that the mortality of immature specimens in both species, the preimaginal developmental time, and adult size were affected by competition. In natural conditions, adult coexistence during the spring-summer period was confirmed. The simultaneity of the two species colonising human corpses is frequent in the studied area, with Ch. albiceps being the dominant species, and L. sericata the relevant species for estimating the minimum postmortem interval.

First Life Table of Synthesiomyia nudiseta (Diptera: Muscidae) From Palearctic Region for Analyzing the Effect on Its Dispersal Ability.

To better understand the population dynamics and dispersal ability of insect species, it is often helpful to derive a life table containing fundamental demographic data. The aim of this study was to determine a life table for the predatory necrophagous species Synthesiomyia nudiseta (van der Wulp, 1883) on a pig liver diet and under controlled laboratory conditions (29.5 ± 2. 5°C, RH 50 ± 15%, and a photoperiod of 12:12). This species has medical and veterinary importance and its distribution extends in tropical and subtropical areas and now it has been established in the southwestern of Europe. The mean adult longevity was 36. 18 ± 2. 06 d and the net reproduction rate, R, was 27.65 offspring/female, the mean generation time, T, was 22. 09 d, the finite rate of increase, λ, was 1. 16 d-1, and the intrinsic rate of increase, r, was 0. 15 d-1. These results indicate that S. nudiseta cannot be considered an r-strategist as the most common synanthropic necrophagous blowflies due to its predatory behavior; however, its invasive and colonist abilities are discussed. This is the first life table study of this species from Palearctic region to analyze the effect of its dispersal ability.

Review of Synthesiomyia nudiseta (Diptera: Muscidae) as a useful tool in forensic entomology.

Synthesiomyia nudiseta (van der Wulp, 1883) is a synanthropic muscid found in tropical and subtropical zones around the world. The larvae of this species are a secondary agent of myiasis with necrophagous habits and play an important role in forensic entomology, as they are used as an indicator of post-mortem interval. Adults can be considered vectors of etiological agents such as Escherichia coli and Shigella dysenteriae. Due to its ability to adapt to different environmental conditions, its high dispersal capacity (shown by its introduction to Europe), its predatory habits in the last larval stage and the difficulty of identifying it, a very important goal is to update our knowledge about this species. Therefore, the main objective of this paper is to review the identification, geographical distribution and biology of this species in order to provide better support to investigations involving this fly.

Hermetia illucens and Hermetia fenestrata (Diptera: Stratiomyidae) Colonization of "Spoiled" Stingless Bee Geniotrigona thoracica (Hymenoptera: Apidae) Hives in Malaysia.

Meliponiculture, the keeping of domesticated stingless bees such as Geniotrigona thoracica (Smith, 1857) (Hymenoptera: Apidae), is an increasingly popular agricultural industry in Malaysia. This study reports the soldier fly (Diptera: Stratiomyidae) species of the genus Hermetia colonizing stingless bee colonies in Malaysia. The larvae were reared in the laboratory to the adult stage and identified through molecular and morphological approaches. Hermetia illucens (Linnaeus, 1758) and Hermetia fenestrata de Meijere, 1904 (Diptera: Stratiomyidae) were identified from the sample provided. Earlier records of stratiomyids in stingless bee nests were misidentified as H. illucens. This paper represents the first identified record of H. fenestrata colonizing a "spoiled" stingless bee colony. In addition, adult and larval morphological differences between both species and the roles of both species in bee nest decomposition are discussed.

Predatory behavior of Synthesiomyia nudiseta larvae (Diptera: Muscidae) on several necrophagous blowfly species (Diptera: Calliphoridae).

Intraguild interactions play a prominent role in sarcosaprophagous communities, so intraspecific and interspecific competition phenomena between fly larvae take place. Synthesiomyia nudiseta is a species that has recently been recorded on human corpses in Europe, and it has been cited in forensic cases in Spain and Italy. The mature larvae are known to be facultative predators on necrophagous fly larvae, but their role as predators is unknown. The aim of this paper is to investigate the predatory behavior of S. nudiseta on the most abundant blowfly larvae in sarcosaprophagous communities in southwestern Europe (i.e., Chrysomya albiceps, Lucilia sericata, and Calliphora vicina). Intraspecific and interspecific competition experiments were carried out to study the effect of this species in the necrophagous diptera community. First-instar larvae were placed in plastic cups with the same amount of pig liver (15 g) at different densities (50, 100, 150, and 300 individuals/cup). Mortality in blowflies increased when S. nudiseta larvae were present: up to 98.40% in Ch. albiceps, 89.60% in L. sericata, and 84.93% in C. vicina. Pre-imaginal developmental time and adult wing size were analyzed and compared under each of the intraspecific and interspecific conditions; both variables were affected by competition in all cases. The implications of the presence of S. nudiseta for sarcosaprophagous community dynamics and its effect on the estimation of postmortem interval (PMI) are discussed.