Forensic Entomology Research Articles

Larval and adult digestive tract of the carrion beetle Oxelytrum discicolle (Brullé, 1840) (Coleoptera: Silphidae)

Oxelytrum discicolle is a necrophagous beetle occurring in Central and South America, with potential use in forensic entomology for investigations in the context of legal medicine. The present work aimed to describe the morphology of the digestive tract of larvae and adults and contributes to the knowledge about the digestion associated with necrophagy. In the three larval instars, the foregut is short and narrow, the midgut is a dilated tube, elongated with a smooth surface, and the hindgut is narrow and long, with small lateral projections and a dilated terminal region. The gut epithelium in the second and third instar larvae is vacuolated in the mid- and hindgut, with high production of apocrine secretions in the midgut lumen. In adults, the foregut is short, with small spines in the cuticular intima that covers the flattened epithelium. The midgut is dilated, with many short gastric caeca with regenerative cells in the blind portion, which differentiate in digestive columnar cells towards the midgut lumen. The hindgut is long and narrow, with an enlarged distal portion with folded epithelium lined by a thin cuticle. The histochemical tests reveal the absence of protein storage granules in the gut epithelium of larvae and adults. The gut characteristics of the carrion beetle O. discicolle are similar to those of other predatory and phytophagous Coleoptera, which may indicate that ancestry may influence the alimentary canal morphology more than the feeding habits.

Impact of invading species on biodiversity: Diet study of the green whip snake’s (Hierophis viridiflavus, L. 1789) in Switzerland

Next-generation sequencing is increasingly used in conservation biology to resolve complex interactions between species, either diet or gut parasites studies. We applied a recent long metabarcoding method to elucidate the green whip snake’s (Hierophis viridiflavus) prey consumption based on DNA extracted from stomach contents. Illegally introduced in Canton of Vaud (Switzerland), three populations of the green whip snake have strongly developed in two regions, East (Chablais) and North. We suspect that this introduced species is threatening part of the local herpetofauna, especially the Asp viper and the Western green lizard in this region. Consequently, an extermination program has been implemented from 2016 to mitigate Hierophis viridiflavus expansion and its impact arising from its generalist diet. Stomach contents of 94 individuals removed from introduction sites were analysed by long metabarcoding. Our study revealed the consumption of 67 prey belonging to 9 species, primarily small mammals and reptiles. The recurrent presence of two parasitic nematodes was also discovered. Although cannibalistic behaviour could not be highlighted with this approach, a scavenging behaviour was suspected based on the presence of an insect used in forensic entomology (Calliphora vicina). These results confirm the opportunistic feeding behaviour of Hierophis viridiflavus and its ability to predate on threatened species. Although 86.6 % of preys were not listed on the Swiss Red List, the impact on the Asp viper population can be important (up to 20 % of consumed preys) and could partially explain its strong decline.

Succession pattern of insects in relation to drowning and poisoning of Rattus norvegicus at Delta State University, Abraka, Southern Nigeria

Forensic study using insects is a veritable tool for tracing crime and cruelty cases. In recent times, forensics is gaining local or international attention. Poisoning and drowning are similar criminal cases occurring in Nigeria, thus, this present study determined insects associated with decaying carcasses of rats drowned and poisoned in Site III, of Delta State University, Abraka, Nigeria. Poisoned and drowned rats were positioned at several mapped spots in undeveloped bushy paths close to the uncompleted University library in replicates. Albino Wistar rats of 0.25 to 0.30kg were killed by poisoning and drowning. The carcasses were observed daily, between the hours of 8 am and 6 pm, with a minimum observation time of one hour per sample. A total of 1318 insect belonging to 3 Orders, 6 Families and 7 insect species was encountered in this study. Musca domestica, Sarcophaga albiceps and Calliphora viciniam were common species associated with poisoning and drowning of rats. Six hundred and eighty-nine (689) insects accounting for 52.3% was recovered from drowned rats while poisoned rats accounted for (12.37%) of insect species as compared to control (35.36%). The differences were significant (p < 0.05). More insects were collected during the decay stage of the drowned carcass (53.17%). The overall duration for decomposition was not significantly faster (F= 0.89, p > 0.05) for drowned carcass (mean ± SD= 21.43 ± 9.10 days) in poisoned carcass (mean ± SD= 9.53 ± 1.75 days) and control (mean ± SD= 13.21 ±2.20 days). The results of this present study have shown that poisoning inhibited insect abundance. The occurrence of dipterans in all stages is an indication that they can be adopted as key species to determining poison and drowned carcasses. Though future studies are required studies to confirm this is required to develop the succession status in forensic entomology studies using other animal models.

Not by the Book: Observations of Delayed Oviposition and Re-Colonization of Human Remains by Blow Flies.

Simple SummaryAtypical blow fly colonization is rarely documented in the forensic entomology literature. We demonstrate one case of an exaggerated delay in blow fly colonization and two cases of blow fly re-colonization after cessation of the consumption phase on human remains at the Anthropology Research Facility (University of Tennessee). We recommend interdisciplinary collaboration to better interpret evidence encountered from scenarios comparable to these examples.Postmortem interval estimations can be complicated by the inter-individual variation present in human decomposition. Forensic entomologists may especially face challenges interpreting arthropod evidence in scenarios that are not “by the book”, or that vary in unexpected ways. Therefore, it is important to report instances where blow fly colonization does not align with expected soft tissue decomposition as blow fly larvae are often used to produce a time of colonization (TOC) estimation to infer a minimum PMI. We followed the decomposition and blow fly activity of three human donors at the Anthropology Research Facility (University of Tennessee). Delayed oviposition occurred on one donor 115 d post-placement, whereas two donors experienced blow fly re-colonization after cessation of the consumption phase, one 22 d and one more than 200 d after blow fly larvae were last observed. A null hypothesis model tested whether the entomological TOC and anthropological total body score (TBS) estimations encompassed the time of placement (TOP) for each donor. While the null hypothesis was rejected for all TOC estimations, it could not be rejected for the TBS estimations. We discuss how the non-linear nature of human decomposition can pose challenges to interpreting blow fly evidence and suggest that forensic entomology practitioners should recognize these limitations in both research endeavors and applied casework.

Pengaruh Beda Suhu Peletakan Bangkai terhadap Pertumbuhan Larva Lalat Chrysomya Megacephala Pada Tikus Wistar (Rattus norvegicus)

Background: Not a few phenomena of abandoned corpses without knowing the length of time of death, to reveal the mystery of abandoned corpses, identification is needed in order to find out post-mortem interval (PMI). With the help of forensic entomologists as investigators and Chrysomya Megacephala flies as the type of animal that first landed on the corpse. The fast or slow growth of flies is also influenced by temperature as the main factor, so by examining the growth of flies with different temperatures, it is possible to calculate the length of time the corpse will die. Methods:This research method is an analytical research true experimental design in the laboratory using the "Posttest Only Control Group Design",The test animals in this study were 18 rats (Rattus norvegicus) which were dislocated in the neck and given an 1cm incision in the abdomen. The treatment was divided into 3 temperature groups, namely 160C, 270C and 390C using an incubator, each of which was placed 10 Chrysomya Megacephala flies. And seen for 5 days in a row in the morning and evening. The analytical test used is the Mann Whitney test. Results:The results obtained when tested using the Mann Whitney test were obtained (p value = 0.010) which means that there is a significant difference between temperatures of 160C and 390C. Meanwhile, at a temperature of 270C with a temperature of 160C and 390C (p value = 0.000), which means that there is a non-significant difference between the treatment at 270C with a temperature of 160C and 390C. Conclusion: Based on the results of this study, it can be concludedthe differences in the growth of Chrysomya Megacephala fly larvae at different temperatures.

Forensic entomology: what insects tell about crime?

Forensic entomology: what insects tell about crime?

Forensic Entomotoxicology: A Brief Look at Sample Preparation Techniques – A Review

Forensic entomotoxicology is a relatively new science whose applications aims the detection of toxic substances through a matrix of necrophagous insects in a crime scene. In addition, it aims the investigation of the impacts of the xenobiotics on these insects, generating impacts in the measurement of the post-mortem interval (PMI). Calliphoridae larvae, the most important insect for forensic entomology, has an average amount of 25% of crude fat and 53% of crude protein, being a complex matrix that requires some sample preparation methodology before inserting the sample in some equipment to perform the chemical instrumental analysis. Sample preparation methods should be applied in order to increase the protection of analytical equipment from impurities present in the arthropod matrix, as well as increase the detectability of the test analyte by the analytical instrumentation of choice. Thus, the objective of the present work is to compile sample preparation techniques since traditional procedures until new approaches found in the scientific literature applied for entomotoxicological analysis in Calliphoridae specimens and respective analytes. It was observed the lack of a complete standardization for entomotoxicological approach, mainly for traditional extractions preparations. In this sense, microextraction-based techniques become an even greater challenge for arthropod–like matrix, especially in specimens from Calliphoridae family for xenobiotics determination. So, the development of sample preparation techniques with more sustainable approaches, such as reduced use of solvents, added to the increase of the powerfulness of analytical instrumental techniques should be encourage in order to improve the forensic entomotoxicology approach.

Entomofauna cadavérica asociada a los restos incinerados de Sus scrofa domestica L., en el centro poblado de Chuyugual, La Libertad, Perú

La determinación del intervalo post mortem a través de la evidencia entomológica es un método muy utilizado para el esclarecimiento de crímenes en entomología forense. El objetivo de esta investigación fue determinar la entomofauna cadavérica y la biodiversidad ecológica asociadas a los restos de Sus scrofa domestica L. El trabajo se realizó en el centro poblado de Chuyugual, La Libertad, se utilizó un ejemplar de “cerdo” de 15 kg, fue incinerado con petróleo diésel y protegido con una jaula de malla metálica. La colecta de los insectos se hizo con las técnicas entomológicas convencionales, determinando las especies con claves taxonómicas especializadas; para la determinación del valor ecológico de entomofauna cadavérica y familias más representativas se usaron los índices de Margalef, Simpson, Shanon y Pielou. La entomofauna encontrada se distribuyó en 2 ordenes, 7 familias, 12 especies y 4 morfotipos. El 35% de abundancia relativa corresponde a la familia Calliphoridae, el 23% pertenecen a los Sarcophagidae, el 18% a los Staphilinidae y el 6% a las familias Musidae, Fannidae, Dermestidae y Silphidae. La biodiversidad es alta en índices de dominancia e índice de Pielou; sin embargo, es baja en índices de riqueza específica y equidad de Shanon. La familia Calliphoridae, tiene índices de diversidad alto; en tanto que, los Sarcophagidae y Staphilinidae muestran índice moderado y bajo, respectivamente. Se concluyó que la entomofauna encontrada en la descomposición de Sus scrofa domestica pertenecen al orden díptera (Calliphoridae, Sarcophagidae, Muscidae y Fannidae) y coleóptera (Staphilinidae, Silphidae y Dermestidae).

Wing measurements are a possible tool for the identification of European forensically important Sarcophagidae

The flesh flies are a group of insects well known for their forensic importance. Reliable identification of these flies relies on the use of either molecular markers or the morphology of the male genital apparatus. Identification of female flesh flies is more time consuming and less reliable than their male counterparts. This is particularly problematic for forensic entomology practitioners, because female flesh flies are more abundant than males in carrion arthropod assemblages. As such, it is critical that alternative methods for flesh fly identification are established that are equally effective for both sexes. One promising technique is the use of wing measurements, which have been shown to be reliable for the identification of some groups of necrophagous Diptera from several geographical regions. We applied this method to the European Sarcophagidae for the first time, using a dataset of 881 specimens representing 29 species and 5 genera. Species identifications were based on 15 landmarks located at wing vein junctions. We also combined our results with data from previous studies of Calliphoridae and Muscidae which utilised the same methodology, enabling the testing of family level identification using wing morphometrics. Species identifications using wing measurements had varied success. While some species were successfully identified without error, others, particularly from the genus Sarcophaga, were often misclassified. Notably, in several species wing measurements successfully identified both males and females. The results presented here suggest that wing measurements are a promising complementary method to other methods for the identification of necrophagous Sarcophagidae especially in material unsorted at the family level. It can also be used to double check identification performed by a taxonomist using traditional methods.

Carrion flies (Insecta: Diptera) found on human cadavers in Chiba prefecture, Honshu, Japan, with the first record of Fannia prisca from a human corpse.

Forensic entomology (FE) involves the collection and analysis of necrophagous insects and arthropods for postmortem interval estimation based on their growth and succession. In Japan, research on FE is limited, and the predominant species of necrophagous insects and their distribution have not been clarified. The present study aimed to clarify the actual situation of insects, targeting Diptera collected from human cadavers, in Chiba Prefecture. We targeted the cases for which specimens could be collected from forensic autopsies conducted at the Legal Medicine Department of Chiba University Graduate School of Medicine or from human bodies handled by the Chiba Police in 2019. We specifically chose cases from which adult insects could be bred. Fifty cases were applicable, and 47 cases were successful in rearing adult flies. Sixteen species of Diptera were identified: six species of Calliphoridae, four species of Sarcophagidae, and a few species of Fanniidae, Muscidae, Phoridae, Piophilidae, and Stratiomyidae. The most frequently observed species were Lucilia sericata (20 cases) and Chrysomya pinguis (18 cases). For the first time, globally, we recorded the presence of Fannia prisca in a human cadaver. In conclusion, this is the first report to reveal the presence of carrion flies in human death cases in Chiba Prefecture, Japan. Research in FE is important in the context of the Japanese natural and social environment since this can aid forensic investigations conducted by authorities.

Family Sepsidae associated with the decomposition of organic matter (Insecta: Diptera)

Sepsidae larvae are coprophagous or, more rarely, scavengers. Most species are associated with mammalian droppings, on which eggs are laid and within which larvae develop. The entire post-embryonic development lasts from 14 to 32 days. Many sepsis apparently plays an important biological role as decomposers of excrements of mammals and other animals. Some species may be of limited hygienic importance due to their association with human faeces. Others are useful tools in Forensic Entomology. The objective of this work is to inventory the biology, ecology, habitat, geographic distribution, taxonomy, life cycle, phenology, biological control, and work carried out on the Sepsidae Family (Insecta: Diptera). The research was carried out in studies related to quantitative aspects taxonomic and conceptual aspects. A literature search was carried out containing articles published from 1926 to 2022. The mini review was prepared in Goiânia, Goiás, from September to October 2021, through the Biological Abstract, Periodicals CAPES and Scielo.

Near infrared spectroscopy (NIRS) coupled with chemometric methods to identify and estimate taxonomic relationships of flies with forensic potential (Diptera: Calliphoridae and Sarcophagidae)

Infrared spectroscopy has been gaining prominence in entomology, such as for solving taxonomic problems, sexing adult specimens, determining the age of immature specimens, detecting drugs of abuse in fly larvae, and can be an important technique in Forensic Entomology. In order to help identify the species of Calliphoridae and Sarcophagidae families, the present study aimed to evaluate the use of near infrared spectroscopy (NIRS) coupled with chemometric methods for separating fly specimens into taxonomic categories and understanding the taxonomic relationship between them. Spectra collected from nine species of flies were subjected to unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA), in which we sought to visualize the relationship between the samples (segregation of genera and families) with subsequent identification. In PCA, the best model was achieved using five principal components (PCs), which explained 99.16% of total variance of the original data set. The first principal component (PC1) and the fourth principal component (PC4) provided the best segregation, the latter being more important in the segregation of the species Chrysomya albiceps, Lucilia eximia, and Ravinia belforti from the others. In the HCA dendrogram, there was a clear separation between the specimens by family (Calliphoridae and Sarcophagidae) and genera (Chrysomya, Lucilia, Oxysarcodexia, Peckia and Ravinia). This study shows that NIRS is efficient to identify flies’ taxonomic properties, such as family and genera, providing quick evidence for the tested species identity.

Entomological identification of the post-mortem colonization of wolf cadavers in different decomposition stages

Human-driven biodiversity loss is progressively becoming a problem with dramatic consequences for the conservation of vital ecosystems. The increasing number of illegal killings of the grey wolf (Canis lupus, Linnaeus, 1758), a threatened species, displays the need for investigation and prosecution of such offences. Forensic entomology makes use of the knowledge about necrophagous insects to estimate a minimum time-since-death interval of the deceased person or animal, which can give important information on a possible perpetrator. The cadaver fauna along five decomposition stages of wolves in Germany was investigated in the period 2014–2021. The insects from 70 wolf cadavers, originating from all over Germany, were provided by the Leibniz Institute for Zoo and Wildlife Research Berlin. The accumulated degree day (ADD) model was applied for the post-mortem interval estimation on wolf cadavers for the first time. A total of 20 coleopteran species and 14 different dipteran species were discovered and identified. Almost 99 % of all insect specimens were from the order of Diptera, and beetles (Coleoptera) accounted for only 1 % of the cadaver fauna. The blowflies (Calliphoridae) are of particular importance for forensic issues, accounting for about 66 % of all families. Carrion beetles (Silphidae) were found as the second most abundant family (about 21 %). In addition, combining all cases, a steadily increasing insect species richness S was detected from early decay to advanced decay (fresh S = 8; bloated S = 12; active decay S = 21; advanced decay S = 34). In the following remains stage, the species number decreased again (S = 24). However, no significant difference in the number of species was found between the stages of decay when the cases were considered individually. The temporal pattern of insect appearance was found to be congruent with those of previous studies. Furthermore, a time of death was determined for each case and compared to the pathologist's estimates. This study provides insights into the arthropod fauna of wolf remains for the first time, applies the ADD-Model for post-mortem interval estimation, and discusses the suitability of forensic entomology for wildlife death investigations.

Effects of cocaine and heroin, and their combination, on the development rate of Calliphora vomitoria (Diptera: Calliphoridae)

Insects present on or near decomposing bodies are collected by forensic entomologists and used to estimate the post-mortem interval. Drugs metabolized by a person before death may affect the rate of development of insects feeding on the corpse. This study aimed to determine the effects of cocaine and heroin main metabolites on the development rate of the Calliphora vomitoria (Diptera: Calliphoridae) and their implications on minimum post-mortem interval determination. Groups of 250 eggs each were placed into four separate pots of 150 g of minced pork meat being either un-spiked, or spiked with benzoylecgonine, morphine, or a combination of both. Larval length (mm) and weight (mg) measurements were taken twice daily and the rate of development of the insects’ life cycle was monitored until eclosion. Results show that cocaine-fed larvae developed less in length and weight than the control group. Heroin-fed larvae showed a more fluctuating pattern, being smaller and lighter than the control group for most of their larval cycle, but overtaking them in both parameters towards pupation. Combination-fed larvae seemed to favour the effects of cocaine. The three conditions also had a significant impact on the length of the insects’ life cycle. Cocaine and drug combination treatments increased the length of the second and third instar stages, but led to the shortening of pupation and accelerated eclosion. Conversely, heroin treatment led to lengthier pupation. Interestingly, the effects of the drug combination seemed to mirror more precisely those of cocaine.These findings indicate that both cocaine and heroin, singularly and in combination, have sizable effects on blowflies’ development rates, potentially biasing post-mortem interval estimations.

Potential application of Gustatory Receptor 1 (CmegGr1) gene as a molecular marker for identification of Chrysomya megacephala (Diptera: Calliphoridae).

Chrysomya megacephala larvae can easily be identified using cheap traditional microscopy techniques. Nevertheless, identification using taxonomy keys may be hampered, if the morphological characteristics of the larvae are incomplete, or immature for microscopic identification. To overcome the difficulty of species determination, molecular identification has gained relevance and is applied in forensic investigations. This study aimed to identify a novel target gene, known as the gustatory receptor 1 gene (CmegGr1), which has never been used for identification. The third instar larvae of Ch. megacephala (n = 30) and eight other forensically important fly species were obtained from two sources; rabbit carcasses and the Forensic Entomology Unit collection. Their DNAs were extracted and the CmegGr1 gene was amplified using polymerase chain reaction (PCR). The resulting sequences were subjected to phylogenetic analysis. A 209 bp fragment of the CmegGr1 gene was successfully amplified in 80% (24/30) of Ch. megacephala samples, while all of the non-Ch. megacephala species were not amplified. The phylogenetic analysis revealed that the evolutionary tree of CmegGr1 shares many traits with the 21a gustatory receptors of Calliphora stygia and Lucilia cuprina (Gr21a), which are also classified as necrophagous fly species. The high specificity of species identification was demonstrated in the present study using DNA barcoding, which led to the conclusion that the CmegGr1 gene could serve as an alternative marker for identifying Ch. megacephala.

Tools and techniques in forensic entomology- A critical review

Tools and techniques in forensic entomology- A critical review

Temperature models of development for Necrodes littoralis L. (Coleoptera: Silphidae), a carrion beetle of forensic importance in the Palearctic region

Analysis of insects can provide evidence in death cases, for example, by answering the question about the time of death. Apart from flies, beetles are the second most useful insect group in forensic entomology. To elucidate the time of death based on insect evidence, developmental models of a given species are necessary. In this study, we developed such models for Necrodes littoralis, a necrophagous beetle, which is common in the Palearctic region and has great potential in forensic entomology. We monitored the development at 10 constant temperatures (14–30 °C). Larvae were reared in aggregations. Thermal summation models, isomorphen and isomegalen diagrams and growth curves were derived using the data. Depending on the temperature, development lasted between about 23 and 89 days. Mortality was high at the extremes of the temperature range. The thermal summation constant for the total development was 434.7 ± 28.86 accumulated degree-days above a developmental threshold of 9.04 ± 0.55 °C. This is the first comprehensive dataset on the development of N. littoralis. Implications for its use in forensic casework are discussed.

Life Cycle and Biometric Study of Hydrotaea capensis (Wiedemann, 1818) (Diptera, Muscidae), a Species of Forensic Interest

Simple SummaryFrom the point of view of forensic entomology, the study of the development times of the species and the factors conditioning them are issues of great importance to estimate the minPMI. Hydrotaea capensis is a Muscidae (Diptera) of forensic interest because of its colonization preferences. Thus, there is a need to have more precise data about its biology to gain insights into the interpretation of its presence in corpses. In this study, the H. capensis life cycle was studied at four constant temperatures, 18, 20, 25 and 30 °C, by recording the duration of its different developmental stages and the length reached in each larval stage, as well as some biometric characteristics of the emerged adults. Our work is the first to provide data on the duration of the life cycle of this species and pointed to some alar features as relevant biometric adult indicators to be considered.One of the most important and perhaps most used applications of forensic entomology concerns the estimation of the minimum post-mortem interval (minPMI), defined as the time interval between death and the actual finding of a corpse. Some Diptera species are critical in these studies because they are the first ones capable of detecting and finding a corpse and are selectively attracted by its decomposing status. Thus, the knowledge of the micromorphology of their preimaginal stages and of their life cycles within a time frame constitutes solid indicators for estimating the minPMI. Hydrotaea capensis is a Muscidae of forensic interest usually considered as a late colonizer of corpses. It is widely distributed, living mainly in warm regions, and present in a wide variety of habitats. In this study, the H. capensis life cycle was studied at four constant temperatures, 18°, 20°, 25° and 30 °C, by recording the duration of its different developmental stages, including the length reached in each larval stage, as well as some biometric characteristics of the emerged adults. Significant differences were observed in the average time of development of most larval stages, with a longer duration at low temperatures, and in the length of each larval stage depending on the temperature, but, in this case, without a clear pattern. Moreover, significant differences were found in some alar features, pointing to them as a relevant indicator to be considered. The data provided will assist forensic entomologists to make more accurate minPMI estimations in cases where H. capensis is present.

Larval morphology and temperature-dependent development models of Fannia pusio (Wiedemann): A forensic indicator with expanding distribution

Fannia pusio (Wiedemann) is originally from tropical and subtropical regions of the Americas, where it has repeatedly been collected from both animal carrion and human cadavers. This species is expanding its distributional range, and it has been introduced to Africa, Asia, Australia, Oceania, and Europe. Newly introduced species may be confused with native species of local arthropod necrophagous assemblages, which from a forensic entomology perspective may impact the accuracy of post-mortem interval (PMI) estimations based on insect evidence. In this work we aim to raise awareness among forensic entomologists of the potential benefits and risks associated with the expanding range of F. pusio. Morphology of all larval instars is documented with a combination of light, confocal laser scanning and scanning electron microscopy. Characters allowing identification from other forensically important Fanniidae are listed. Thermal requirements for the development of immature stages of F. pusio were examined under nine ambient temperatures. Models describing changes in larval body length over time were produced for eight different temperatures. The thermal summation constant (k) and developmental zero (Tmin) were calculated for six developmental events: hatching, first ecdysis, second ecdysis, wandering, pupariation, and eclosion.

Forensic entomology: A novel approach in crime investigation

Forensic entomology is an application of studies related to insects and other arthropods in legal matters. Depth knowledge and experience of the biodiversity, biology, ecology, and behavior of forensic insects found on a human corpse or at a crime site, can provide information about time since death, location of the crime, and in some cases cause of death. Although forensic insects are used in crime investigation for three to four decades, it aroused recently as a very popular and independent branch of forensic science in crime investigation. While observing and examining insects on a corpse, knowledge of regional insects’ assemblages and their population dynamics play an important role in medico-legal entomology for an efficient criminal investigation. Forensic entomology has three components, named as urban, stored products, and medico-legal. As different groups of insects are attracted to different stages of decay, forensic insects invade the corpse in a typical sequence. The type of insects’ colonization found on corpses provides important information about the decomposition stage. Calliphoridae provides valuable evidences, particularly in determining time since death in criminal matters, where the time since death is prolonged and use of other conventional methods for estimation of time since death is limited. Two well-established ways used for estimation of post mortem interval are based on maggot’s development and succession waves of entomofauna. The latest scientific and technological developments in the field, such as its combined approach with forensic toxicology, forensic palynology, DNA based molecular identification of insect species, and other various methods to estimate post mortem interval, are many emerging fields under this periphery and forensic entomology lately became very popular among criminal investigators and forensic entomologists.