Forensic Entomology Research Articles

DNA-based and taxonomic identification of forensically important Sarcophagidae (Diptera) in southeastern Spain

Studying dipterans at the scene of a death can provide essential information for interpreting the evidence and help to reconstruct the events happened to a corpse in the past. Molecular tools have been employed for identification at specific levels in the cases of cryptic species or poorly conserved specimens. Identification of specimens is essential in forensic entomology since each species has a specific growth rate, which determines the calculation of the minimum post mortem interval (minPMI). In addition, phylogeographic reconstruction within a species can help to differentiate the haplotypes from a geographic area, thereby helping to clarify the possible relocation of a corpse. The morphological identification of Sarcophagidae species is often difficult, especially for the females. This is an important Diptera family since some of its species are among the first to reach a corpse, especially in warm areas. In this study, we compared the sarcophagids found in human corpses in forensic cases in Alicante (southeast of Spain) with specimens collected from baited traps in the same area and surrounding provinces. In total, 189 specimens were collected, comprising 72 from forensic cases and 117 from baited traps. Molecular identification was conducted by sequencing the cox1 mitochondrial gene and analyzing the sequences using ABGD, GMYC, and BIN species delimitation methods. The median joining algorithm in the PopART program was used to construct phylogeographic networks. Eight species in the family Sarcophagidae were identified. The most widely collected species were Sarcophaga argyrostoma and Sarcophaga tibialis. The haplotype networks obtained for these species did not indicate a clear geographic distribution of haplotypes. The S. argyrostoma samples from Alcoy were clearly isolated. The results demonstrated that this method is useful for identifying Sarcophagidae samples in forensic investigations and it can be employed for minPMI estimation.

The implication of morphometrics and growth rate of dipteran flies in forensic entomotoxicology research: a review.

Forensic entomotoxicology integrates toxicology into forensic entomology to estimate minimum postmortem interval (PMImin) and circumstances of death where toxicants and poisonous substances are the suspected cause of death. Forensic entomotoxicology not only confirms the presence of toxicants in insects feeding off a cadaver but also studies its effect on the bio-morphometry and growth rate of insects. This review article highlights the effects of various toxicants on forensically important species of dipteran flies. It also discusses the parameters that may affect accuracy in estimation of time since death. The bio-physical effects of toxicants (excluding the analytical approach for qualitative detection) would help understand the trends in forensic entomotoxicological research worldwide.

Genetic diversity ofCalliphora vicina(Diptera: Calliphoridae) in the Iberian Peninsula based oncox1, 16S and ITS2 sequences

AbstractThe study of Diptera at the scene of a crime can provide essential information for the interpretation of evidence. Phylogeographic reconstruction could help differentiate haplotypes of a dipteran species in a geographical area, clarifying, for example, the details of a possible relocation of a corpse. In addition, inferring the ancestral areas of distribution helps to understand the current status of the species and its biogeographic history. One of the most important species in forensic entomology is Calliphora vicina Rovineau-Desvoidy, 1830 (Diptera: Calliphoridae). The aim of this work is to increase our knowledge of this species in the Iberian Peninsula using 464 specimens from Spain and Portugal. These samples were identified using morphological keys and by molecular methods using fragments of the cox1, 16S and ITS2 genes. The phylogeographic history of these populations was inferred from haplotype networks and the reconstruction of ancestral areas of distribution. The molecular results corroborated the morphological identifications of the samples. Phylogeographic networks showed no geographical structure, as haplotypes are shared among almost all populations. reconstruct ancestral state in phylogenies analyses showed a high rate of movement among populations, possibly related to human activity. These results suggest that this species had a very rapid and recent spatial and demographic expansion throughout the Iberian Peninsula.

Developmental Models of the Forensically Important Carrion Beetle, Thanatophilus sinuatus (Coleoptera: Silphidae).

Carrion beetles of genus Thanatophilus (Leach, 1815) are an important group of necrophagous insects, with great potential for forensic entomology in temperate zones of Africa, America, Asia, and Europe. Developmental models for majority of Thanatophilus species remain unknown. In this study, we will provide new thermal summation models for all the developmental stages of Thanatophilus sinuatus (Fabricius, 1775), one of the most abundant and widespread species of the genus. The beetles were bred at seven different constant temperatures, and developmental time was measured for each developmental stage (egg, three larval instars, postfeeding stage, and pupa). Temperature-sex influence was tested, and thermal summation constants were calculated to be used for postmortem interval estimation during criminal investigations.

Isolation and characterization of human DNA recovered from Cimex hemipterus (F.) (Hemiptera:Cimicidae).

The ability to isolate and generate a DNA profile from human DNA recovered from tropical bed bugs (Cimex hemipterus) for identifying individuals can be useful for public health, forensic, and medical entomology. In this study, genomic DNA was recovered from both male and female bed bugs at every time interval tested (0, 1, 3, 5, 7, 14, 30, and 45days post blood meal). The total DNA concentrations recovered from male bed bugs ranged from 12.93 to 65.97ng/µL, while the total DNA concentrations from female bed bugs ranged from 8.93 to 44.53ng/µL. However, based on the results from the BLAST search and PCR products, human DNA could be detected from female bed bugs at 0, 3, 5, 14, and 30days post blood meal using the D18S51 marker. Concentrations of PCR products of the D18S51 locus from male bed bugs ranged from 4.20 to 35.50ng/µL, whereas, for female bed bugs, concentrations ranged from 4.31 to 22.47ng/µL. These were generally higher compared to the PCR products of the first hypervariable part (HVR1) marker. The results indicate the HVR1 locus was less sensitive than the D18S51 locus.

Succession of Dipteran Fly Maggots on Poisoned Pig Cadavers at Nnamdi Azikiwe University, Awka, Nigeria

Dipteran maggots found on a cadaver are used to estimate its time of death but the time may be incorrect if death occurred due to ingestion of poison. Decomposition of a zinc phosphide intoxicated and strangulated pigs (Sus scrofa Linn.) were evaluated in this study. They were deposited in a forest during the rainy season and repeated during the dry season at Awka, Nigeria. Decomposition duration and stages of decay of the pig cadavers were recorded. Maggots found on the cadavers were collected, reared to adulthood and were identified. Similar maggot samples were assessed for residues of zinc and phosphorus with an Atomic Absorption Spectrophotometer. Both pig cadavers completely decomposed within 10 and 14 days during the rainy and dry seasons, respectively. Appearance and emergence of three dipteran maggot families were observed on the cadavers in a successional pattern. Zinc and phosphorus residues were detected in the maggots from the poisoned cadavers while they were not detected in the maggots from the strangled cadavers. The three dipteran maggot families are recommended as a valuable tool in forensic entomology for the estimation of elapsed time of a questionable death and the dipteran bodies would also be useful for toxicological analysis.

Intrapuparial Age Estimation of Forensically Important Dohrniphora cornuta (Diptera: Phoridae).

Dohrniphora cornuta (Bigot) is a forensically important phorid fly indoors and in burial environments. The determination of a minimum postmortem interval (PMImin) often relies on the determination of the age of the immatures. Although the larval development data of D. cornuta under different temperatures has been established, the intrapuparial stage which lasts for about half of the total immature development is scarce. In this study, we investigated the key morphological changes during intrapuparial development at constant temperatures (15, 18, 21, 24, 27, 30, 33, and 36°C), with an aim to estimate the intrapuparial age of D. cornuta. Puparia were sampled at 12-h (24, 27, 30, and 33°C), 24-h (18 and 21°C), and 48-h (15°C) intervals. The morphological developments within the puparium were analyzed using a stereomicroscope after the puparium was removed. The average minimum duration of intrapuparial stage was inversely related to temperature, ranging from 184.79 ± 3.00 h at 30°C to 1102.86 ± 25.55 h at 15°C for female, and 197.40 ± 4.12 h at 30°C to 1175.33 ± 18.55 h at 15°C for male. It did not develop at 36°C. Some morphological traits that changed during development within the puparium could be used as age markers. According to these changes, the intrapuparial stage of D. cornuta was divided into nine stages which could be used for both sexes. This study provides relatively systematic development data of D. cornuta intrapuparial for the estimation of PMImin in forensic entomology.

First record of flesh fly Sarcophaga (Liosarcophaga) aegyptica (Diptera: Sarcophagidae) from India

Accurate identification of insect specimens is an essential requirement in forensic entomology. This study aimed to collect adult sarcophagid flies and to identify them based on the male genitalic characters. Its the first report of Sarcophaga (Liosarcophaga) aegyptica from India. The fly has collected, from pig carcasses placed in indoor, outdoor, and aquatic environments during bloated & advanced decay stages of decomposition. The carcasses have placed for decomposition during winter (2015) and spring (2017) seasons in the rural area of Punjab (India). S. (L.) aegyptica belongs to subgenus Liosarcophaga of Superfamily Sarcophagidae, and Salem first reported it from Egypt in 1935. S. (L.) aegyptica is a subtropical thermophilous species that has a wide distribution in the Eastern Hemisphere. The species is infrequent and generally attracted to meat and feces. Their larvae feed and develop on vertebrates carcasses. The species show peculiarity from other species of this genus by the structure of inner forceps of genitalia, which is straight and slightly widened at the subterminal end. Another disparity is in the process of the apical plate of paraphallus, which is pointed at the end. This family has great importance in the field of forensic entomology as they visited immediately on carcasses after Calliphoridae. The fly is of medical importance as these flies are responsible for causing myiasis in humans and animals; hence, they are of medical importance and useful in the estimation of post mortem interval (PMI).

Chrysomya albicepsWiedemann (Diptera: Calliphoridae) colonising poisoned rabbit carcasses

AbstractChrysomia albicepsWiedemann (Diptera: Calliphoridae) is one of the first insects to colonise human and animal carrion and thus one of the most important insects in forensic entomology. Since the presence of these blow flies have been reported in most of the provinces in Saudi Arabia, we analyse the succession patterns ofC. albicepson decomposing rabbit carcasses injected with heroin or administered orally with alcoholic beverages. Samples of flies from the carcasses of heroin or alcohol‐treated and untreated rabbits were obtained for 15 days post mortem. A total of 1,297 and 1,426 flies were attracted to rabbit carcasses during the heroin and alcohol tests, respectively. The blow flies appeared in different developmental instars (larvae, pupae and adults), and at all stages of decomposition. Administration of higher concentrations of heroin or higher amounts of alcohol were generally associated with an increase in the number of blow flies drawn to rabbit carcasses (P < 0.05). The highest number of blow flies were attracted during the decay stage of decomposition, and the lowest during the fresh stage. In the case of medicolegal investigation, whenC. albicepsused as a forensic indicator, it is recommended that the impact of heroin or alcoholic beverages on the succession patterns be considered.

Effect of Environment Factors on Life Cycle of Forensic Entomology: A Review

Pests play an important ecological part in organic matter decomposition. As a natural means of survival,sarcosaprophagous fly usually prefers to locate and consume a food source such as a cadaver as a naturalmeans of survival. Sarcosaprohagous fly larvae are frequently encountered by judicial entomologistsduring post mortem investigations. The most relevant colonizers are the oldest individuals derived fromthe first eggs placed on the body. The stage of the oldest maggots provides the accurate estimate of postmortem interval. Judicial entomology is predictable in numerous countries as a serious tool for forensicinvestigations. Judicial entomology requires extensive information on the local pest population, is subjectto many environmental factors (temperature being one of the principle variables), and they need access tothe bodies. The maggot fly crawling on the dead bodies are broadly considered to be just another disgustingelement of decay and are not collected at the periods of autopsy. This paper reviews several methods of PMIassessment, this procedure comprises the aggregation of convenient information for the growth of the typesof pest at a variation of pertinent temperatures and contemplation of the extra living things and nonlivingthings aspects that can disturb evolving average.

Decomposition process and arthropod succession on pig carcasses in Quebec (Canada)

Necrophagous arthropods are essential ecosystem decomposers and are important indicator species in the discipline of forensic entomology. Studies around the world have evaluated the succession of arthropods on animal carcasses, but no published data are available for the province of Quebec (Canada). The objective of this study was to evaluate the diversity of arthropods associated with pig carcasses in Quebec, and to determine the colonization sequence of the different families/species throughout the decomposition process. Three pig carcasses were deposited in a small woodland area in Trois-Rivières, in mid-June 2019. The decomposition process and the arthropod community were studied until the beginning of November (first snowfall) by visual observation, and sample collection on the carcasses, using an entomological net and pitfall traps. Five species of blow fly (Diptera: Calliphoridae) were found to lay eggs on the carcasses: Calliphora livida, C. vomitoria, Lucilia illustris, Phormia regina, and Protophormia terraenovae. Eggs/larvae of the first three species were recorded during the first week only (fresh stage-beginning of active decay), while the other two species were recorded throughout the decomposition process until the dry remains stage. Coleoptera were observed from day 0 to day 141 (end of experiment). Some families/species were associated with early stages of decomposition (e.g. Necrophila americana, Silphidae), while others were only found during the dry remains stage (e.g. Carnicops pumilio, Histeridae).

Evaluation of activities of dipteran maggots on a poisoned pig cadaver at Nnamdi Azikiwe University Awka, Nigeria

BackgroundForensic entomology is evolving into entomotoxicology, which is a critical approach in forensic toxicology that alternatively assesses presence of toxins in insects that have eaten a decomposing cadaver. Toxic substances in or on a dead body may accumulate in the tissues of fly maggots while feeding on the body and thus may alter their developmental rate. Thus, four out of eight healthy pigs (Sus scrofa Linn.) that weighed on the average 22.3 ± 1.9 kg were sacrificed with zinc phosphide as food poison, while the remaining four pigs were sacrificed by strangulation during the rainy and dry seasons of 2014 and 2015 respectively. Their bodies were deposited in a building to mimic indoor decomposition. The building is on 6° 15′ 18.06″ N and 7° 06′ 41.37″ E at Nnamdi Azikiwe University Awka, Anambra State, Nigeria. The effect of the zinc phosphide on the decomposition duration of the cadavers was monitored. Toxicological assessment of zinc and phosphorus on maggots found on the cadavers was performed with an atomic absorption spectrophotometer.FindingsThe zinc phosphide did not affect the decomposition duration of the cadaver and did not prolong or shortened the life cycle of the fly maggots when compared with the control (strangled pig cadaver). For the poisoned cadavers, the atomic absorption spectrophotometer detected zinc in the maggot tissues collected from them while phosphorus was not detected. Neither zinc nor phosphorus was detected in the maggot tissues collected from the strangled cadavers.ConclusionsThe study showed that the zinc component in the zinc phosphide commonly used as rodenticide in Awka can be detected in maggots collected from such a suspected poisoned cadaver. Other implications related to toxicological studies on cadaveric insects in forensic entomology and serving as alternative matrices in forensic toxicology in any questionable death were also highlighted.

Diversity of Public Health and Forensic Important Flies Using Three Measures of Hill Numbers in Iran

Introduction: Dipteran species (flies) are one of the most important insects within the public health and forensic fields. Previous studies have shown that flies play an important role in transmitting the diseases and also estimating the time of death, but their diversity by new methods has been less studied. Methods: Dipteran specimens were collected from rabbit carcasses during spring and summer 2019 and then identified. We used the three measures of Hill numbers (q=0,1,2) to compare the species diversity between the seasons. The analysis was performed with an R package (iNEXT) that provided in 2014. Results: During the present study, 12 dipteran species were collected on rabbit carcasses. L. cuprina and M. stabulans were recorded only from the remains of rabbits in summer. The analysis with iNEXT software showed that species richness (q = 0) in spring is lower than summer and this difference was significant. While, the value of Shannon and Simpson diversity index (q = 1, 2) in summer was lower than in spring. Shannon index value was not significantly different between the seasons, as its confidence intervals almost completely overlapped, but a significant difference in Simpson index was detected between the seasons. Conclusion: We conclude that Ch. albiceps, L. sericata and C.vicina are more frequent flies in the study area and dipteran species are more diverse in spring. The current study provided a database in the field of public health and forensic entomology that could be useful for estimating minimum postmortem intervals and also in vector control programs.

Contrasting insect activity and decomposition of pigs and humans in an Australian environment: A preliminary study

Non-human vertebrate animals, primarily domestic pigs, have been widely used in forensic science research as analogues for humans due to ethical and logistical constraints. Yet the suitability of pigs to mimic human decomposition and entomological patterns remains largely untested, and explicit comparative research in this area is lacking. We compared the decomposition rates and insect communities found at pig and human remains during summer and winter at the Australian Facility for Taphonomic Experimental Research (AFTER). Pigs decomposed faster than humans, with pigs entering active decay earlier in both summer and winter, and humans undergoing desiccation rather than skeletonisation. There was also a delay in the colonisation of humans by both flies and beetles. Species richness of these necrophagous taxa was between two and five times higher during the first two weeks of decomposition on pigs compared to humans during both summer and winter. Insect species composition was also significantly different between pigs and humans in each season. We interpret our findings to mean that the difference between humans and pigs, such as their mass, diet, medical history, or their microbiomes, might be causing different decomposition processes and altered timing or production of chemical cues for insect colonisation. Although preliminary, our results suggest that pigs might not be accurate substitutes for humans in particular fields of taphonomy and forensic entomology. Our findings also have broader implications for the reliability of forensic studies using pigs as models for humans, and highlight the need to recognise intrinsic differences between animal models and humans.

Metrological framework for selecting morphological characters to identify species and estimate developmental maturity of forensically significant insect specimens

Accurate age estimates of immature necrophagous insects associated with a human or animal body can provide evidence of how long the body has been dead. These estimates are based on species-specific details of the insects’ aging processes, and therefore require accurate species identification and developmental stage estimation. Many professionals who produce or use identified organisms as forensic evidence have little training in taxonomy or metrology, and appreciate the availability of formalized principles and standards for biological identification. Taxonomic identifications are usually most readily and economically made using categorical and qualitative morphological characters, but it may be necessary to use less convenient and potentially more ambiguous characters that are continuous and quantitative if two candidate species are closely related, or if identifying developmental stages within a species. Characters should be selected by criteria such as taxonomic specificity and metrological repeatability and relative error. We propose such a hierarchical framework, critique various measurements of immature insects, and suggest some standard approaches to determine the reliability of organismal identifications and measurements in estimating postmortem intervals. Relevant criteria for good characters include high repeatability (including low scope for ambiguity or parallax effects), pronounced discreteness, and small relative error in measurements. These same principles apply to individuation of unique objects in general. Key points Metrological rigour can increase in forensic entomology by selecting measurements based on their metrological qualities. Selection of high-quality features for morphological identification of organisms should consider these criteria: (1) pronounced discreteness of features (minimising group overlap or maximizing interval); (2) high repeatability of assessment (such as symmetrical width rather than asymmetrical length); (3) small relative error in measurement (selecting the physically largest continuous rigid feature for measurement). These metrological principles also apply to individuation of unique objects in general.

Eye-background contrast as a quantitative marker for pupal age in a forensically important carrion beetle Necrodes littoralis L. (Silphidae)

Insect pupae sampled at a death scene may be used to estimate the post-mortem interval. The pupal age is however difficult to estimate, as there are no good quantitative markers for the age of a pupa. We present a novel method for pupal age estimation based on the quantification of contrast in intensity between the eyes of a pupa and the middle grey photography card as a standard background. The intensity is measured on a standardized scale from 0 (perfect black) to 255 (perfect white) using computer graphical software and pictures of the eye and the background taken with a stereomicroscope. Eye-background contrast is calculated by subtracting the average intensity of the eye from the average intensity of the background. The method was developed and validated using pupae of Necrodes littoralis (Linnaeus, 1758) (Coleoptera: Silphidae), one of the most abundant beetle species on human cadavers in Central Europe. To develop the model, pupae were reared in 17, 20 and 23 °C, with a total of 120 specimens. The method was validated by three raters, using in total 182 pupae reared in 15, 17, 20, 23 and 25 °C. We found a gradual increase in eye-background contrast with pupal age. Changes followed generalized logistic function, with almost perfect fit of the model. Using our method pupal age was estimated with the average error of 8.1 accumulated degree-days (ADD). The largest error was 27.8 ADD and 95% of age estimates had errors smaller than 20 ADD. While using the method, different raters attained similar accuracy. In conclusion, we have demonstrated that eye-background contrast is a good quantitative marker for the age of N. littoralis pupae. Contrast measurements gave accurate estimates for pupal age. Our method is thus proven to be a candidate for a reliable approach to age insect pupae in forensic entomology.

Forensic Entomology: an inventory of Arthropods collected on the decomposing pig Carrions during the dry season in Warri, Southern Nigeria

Arthropods found on the pig carrions in the dry season in the Warri city at 05°32’34.95"N and 05°44’39.834"E from 10th December 2017 to 10th February 2018 studied. Three pigs were killed and their decomposition monitored for 60 days, arthropods were collected with the aid of sweep nets, brushes, handpicking and pitfall traps while the soil below the decaying pig carrions were searched extensively twice daily for the first week and once daily for the remaining weeks. Data analysis was done by Microsoft excel while graphs were used to demonstrate the frequencies of the arthropods in every phase of decomposition, pie chart was used to elucidate stages of putrefaction and their respective periods. The outcome of the study showed five exclusive stages of decay: fresh, bloated, active decay, advance decay and dry decay correspondingly. The fresh stage took shortest days of 2 as the dry decay took longest days of 41. A total of 1495 arthropods were collected, at the fresh stage, there were 244 arthropods, while 213 were Diptera, only 19 were Hymenoptera and 12 were also Coleoptera but at the bloated stage of decomposition, a total of 273 arthropods were recorded, Diptera were 223 as hymenoptera were 21 and Coleoptera were 29 while at the active decay stage of decomposition there were a total of 437 arthropods, 333 of them were Diptera, 29 were Hymenoptera as 75 were Coleoptera but at the advance decay stage of decomposition, there were a total of 438 arthropods, 225 of them were Diptera, 30 were Hymenoptera as 91 were Coleoptera but at the dry decay stage of decomposition, only 195 arthropods were recorded, 96 of them were Diptera, 21 were Hymenoptera and 78 were Coleoptera in that order, for the reason that the Coleoptera and Diptera used the decaying pig carrions for breeding of their offspring, they could be used in the estimation of the time after death hence are of immense forensic importance while the role of the recorded Hymenoptera could also be of great importance as the tears and wears that they created on the carrions could be cause of error in the estimation of the time of death and their predatory role could also give a fake entomofauna documentation data, more researches of this nature are to be carried out in Warri city and other neighboring communities in order to document reliable database of arthropod of forensic importance in the oil rich city.

SHORT COMMUNICATION WING SHAPE VARIATIONS OF MALAYSIAN FORENSIC SCUTTLE FLIES (DIPTERA: PHORIDAE) INCLUDE SEXUAL DIMORPHISMS

Geometric morphometric analysis recently has expanded to insects of forensic importance, mainly adult flies, as correct and valid species identification is important in forensic entomology. The objective of this research was to investigate morphological variations between two forensically important scuttle flies (Diptera: Phoridae) in Malaysia, i.e. Megaselia scalaris (Loew, 1866) and Megaselia spiracularis Schmitz, 1938, based on wing shape analysis. A total of 16 geometrical landmarks was defined and analysed with geometric morphometric procedures using MorphoJ software. Wing centroid size, which represented wing shape, was statistically different between species and sexes. By using residuals from the allometric effect, canonical variate analysis separated all defined groups in different distinct clusters and further cross validated by both species and sexes. Between species, male M. scalaris had broader wing shape than male M. spiracularis, whilst in the female, M. scalaris had a narrower shape at the tip of the wing. Within M. scalaris group, females had broader wing shape at the base than males, whereas in M. spiracularis, the females had narrower shape at the base of the wing than the males. The geometric morphometric analysis in distinguishing forensically important species could be expanded for further investigation, especially in Phoridae family.

Ultrastructural studies of sensilla in one fly of forensic importance

Taxonomic identification is essential in the field of forensic entomology. Insects are important in the decomposition of cadavers. The flies are generally attracted to cadavers and one of the most important contributions is to estimate the postmortem interval. The scanning electron microscopy (SEM), which allows rapid and accurate identification of different species of forensics flies, has been highlighted as it allows better visualization of the external morphology of immature and some adults. The purpose of this study was to examine in details the morphological aspects of sensilla on the antennae of female and male of Xanthacrona bipustulata Wulp using SEM, since many of them could not be observed just by the use of light microscopy.

Developmental Plasticity of the Flesh Fly Blaesoxipha plinthopyga (Diptera: Sarcophagidae) on Different Substrates.

Forensic entomologists rely on laboratory growth data to estimate the time of colonization on human remains thus extrapolating a minimum postmortem interval (PMI) if assumptions are satisfied. The flesh fly Blaesoxipha plinthopyga (Wiedemann) is one species that occurs in casework in Idaho, Texas, and central California. Because of the few laboratory studies on the development of this fly, the following study was conducted to determine if different substrates impact immature development of the species. In this study, flies were reared on different substrates that are likely to be encountered at indoor and outdoor scenes (Wet Sand, Dry Sand, Clothes [Polyester fibers], and Carpet [Polypropylene fibers]) to determine the influence of substrate on larval, intrapuparial, and total immature development times at 25°C, 50% RH, and 14:10 (L:D) h cycle. The results revealed that substrate significantly affected minimum immature development times without affecting the sexes differently; though a female bias in sex ratio was observed consistently. Average minimum larval developmental times were 160-179 h with a significantly faster development in Carpet than in Clothes. Similarly, average minimum intrapuparial developmental times were 331-352 h; fastest on Carpet and the slowest in Dry Sand. For this species, it may be important to consider the substrates encountered at a death scene as they may affect the development of B. plinthopyga (Wiedemann) in casework by up to 29 h at 25°C and 50% humidity. These effects will also be important to consider when planning future development studies with the species.