Survival of Calliphora vicina (Diptera: Calliphoridae) embryos under cold temperature conditions: forensic implications.

Most blow flies (Diptera: Calliphoridae) species are sarcosaprophagous during the larval stage, primarily feeding on the soft tissues of carcasses during the early stages of decomposition, making them valuable forensic indicators for minimum post-mortem interval (minPMI) estimations. Like other insects, their developmental rates are strongly influenced by the environmental temperature. Although several studies have examined the influence of temperature on the development of different blow fly species, the impact of cold temperatures remains largely unstudied, despite its potential forensic implications.

Influence of photoperiod on the developmental times of the forensically relevant blow fly species Calliphora vicina (Diptera: Calliphoridae).

Blow flies (Diptera: Calliphoridae) are frequently used in forensic investigations due to their rapid colonization of cadavers. As with other insects, environmental temperature strongly influences their developmental rates. While published research has typically explored not only the impact of the environmental temperature, but also of other factors like tissue type and drug presence on developmental rates, the influence of photoperiod on the developmental rates of forensically relevant blow fly species has remained largely underexplored.

An effective method for preparing histological sections of blow fly intra-puparial stages for minimum PMI estimations.

Blow flies (Diptera: Calliphoridae) are generally early colonisers of fresh cadavers, enabling the estimation of a minimum post-mortem interval (PMI) based on an accurate aging of the oldest immature stages associated with a cadaver. In blow flies, the pupal stage and the subsequent development of the adult take place inside a protective case, the puparium, formed from the hardened and darkened cuticle of the third instar larva. Because the puparium is an opaque structure that shows virtually no external changes, qualitative analyses of the internal tissues can be very informative for determining reliable age-specific morphological markers.

Methods for the optimal preservation of blow fly intra-puparial forms for morphological analysis in forensic casework.

Accurate minimum post-mortem interval (minPMI) estimations often rely on a precise age determination of insect developmental stages, which is significantly influenced by environmental temperature. An optimal preservation of the entomological samples collected at crime scenes is pivotal for a reliable aging of immature insect samples. For blow flies (Diptera: Calliphoridae), the most widely used insect indicators in forensic investigations, an appropriate preservation of tissues is particularly important in the case of puparial samples because aging methods for intra-puparial forms usually depend on morphological analyses; however, although informative soft tissues and structures could be discoloured and/or distorted if they are not properly fixed, there is a lack of studies to assess different methods for the optimal preservation of intra-puparial forms collected in forensic investigations.

Larval anatomy of the digestive and excretory systems of the pharyngeal bot fly, Pharyngomyia picta (Diptera: Oestridae).

Oestrid flies (Diptera: Oestridae) are obligate parasites of mammals during their larval stage and show anatomical adaptations for the infestation of host tissues. Unlike the species that parasitize domestic mammals, those oestrid species that infest wild mammal hosts remain poorly known. With the use of x-ray micro-computed tomography, we describe for the first time the anatomy of the digestive and excretory systems of the second and third larval instars of Pharyngomyia picta (Meigen), a parasite of cervids that, like other species within the subfamily Oestrinae, causes nasopharyngeal myiasis.

Morphological and molecular characterization of puparia of Piophilidae species of forensic relevance.

Piophilidae are a small family of Diptera with a worldwide distribution and which are historically associated with human activities. In addition to their economic importance, piophilid larvae can also be of medical and legal relevance. Within a medicolegal context, piophilids are frequently associated with cadavers in advanced stages of decomposition, thus being potentially useful forensic indicators and they have been reported also from archaeo-funerary contexts.

Micro-CT visualization of a promastigote secretory gel (PSG) and parasite plug in the digestive tract of the sand fly Lutzomyia longipalpis infected with Leishmania mexicana.

Leishmaniasis is a debilitating disease of the tropics, subtropics and southern Europe caused by Leishmania parasites that are transmitted during blood feeding by phlebotomine sand flies (Diptera: Psychodidae). Using non-invasive micro-computed tomography, we were able to visualize the impact of the laboratory model infection of Lutzomyia longipalpis with Leishmania mexicana and its response to a second blood meal. For the first time we were able to show in 3D the plug of promastigote secretory gel (PSG) and parasites in the distended midgut of whole infected sand flies and measure its volume in relation to that of the midgut.

Looking Back to Move Forward: How Review Articles Could Boost Forensic Entomology.

The Locard's exchange principle (1930) holds that the perpetrator of a crime leaves traces behind that can later be sampled and used as forensic evidence [...

Micro-CT imaging of Onchocerca infection of Simulium damnosum s.l. blackflies and comparison of the peritrophic membrane thickness of forest and savannah flies.

Onchocerciasis is a neglected tropical disease (NTD) caused by Onchocerca Diesing 1841 (Spirurida: Onchocercidae) nematodes transmitted by blackflies. It is associated with poverty and imposes a significant health, welfare and economic burden on many tropical countries. Current methods to visualize infections within the vectors rely on invasive methods.

Major differences in the larval anatomy of the digestive and excretory systems of three Oestridae species revealed by micro-CT.

Oestrid flies (Diptera: Oestridae) do not feed during the adult stage, so they depend on an efficient assimilation and storage of nutrients during their parasitic larval stage. We describe the general morphology and provide volumetric data for the digestive and excretory organs of the three larval instars of the nasal bot fly Oestrus ovis L., using micro-computed tomography.

Internal morphological changes during metamorphosis in the sheep nasal bot fly, Oestrus ovis.

During the larval stage, oestrid flies (Diptera: Oestridae) are obligate parasites, whereas during the adult stage they are free-living and do not feed. Like other cyclorrhaphous flies, oestrids undergo metamorphosis inside an opaque puparium, formed by the contracted and hardened cuticle of the third-instar larva. The present study documents the internal morphological changes taking place during metamorphosis of the sheep nasal bot fly, Oestrus ovis L.

Wing morphometrics for the identification of Nearctic and Palaearctic Piophilidae (Diptera) of forensic relevance.

The Piophilidae (Diptera) are a family comprising about 80 species, several of them of high economic and forensic relevance. An unequivocal species identification is crucial for designing effective control measures or to provide reliable estimations of the minimum post mortem interval. However, the identification may sometimes not be possible, either because the diagnostic morphological characters are not easily observable or very fragile, or because of a poor DNA quality and/or unavailability of reference molecular signatures.

Estimating crime scene temperatures from nearby meteorological station data.

The importance of temperature data in minimum postmortem interval (PMI) estimations in criminal investigations is well known. To maximise the accuracy of PMI estimations, it is imperative to investigate the different components involved in temperature modelling, such as the duration of temperature data logger placement at the crime scene and choice of nearest weather station to compare the crime scene data to. Currently, there is no standardised practice on how long to leave the temperature data logger at the crime scene and the effects of varying logger duration are little known.

Avoidance of carnivore carcasses by vertebrate scavengers enables colonization by a diverse community of carrion insects.

Carrion resources sustain a complex and diverse community of both vertebrate and invertebrate scavengers, either obligate or facultative. However, although carrion ecology has received increasing scientific attention in recent years, our understanding of carrion partitioning in natural conditions is severely limited as most studies are restricted either to the vertebrate or the insect scavenger communities. Moreover, carnivore carcasses have been traditionally neglected as study model.

Visualization of insect metamorphosis.

Metamorphosis and, in particular, holometaboly, the development of organisms through a series of discrete stages (egg, larva, pupa, adult) that hardly resemble one another but are finely adapted to specific roles in the life cycle of the organism, has fascinated and mystified humans throughout history. However, it can be difficult to visualize the dramatic changes that occur during holometaboly without destructive sampling, traditionally through histology. However, advances in imaging technologies developed mainly for medical sciences have been applied to studies of insect metamorphosis over the past couple of decades.

Long-term insect successional patterns on pig carcasses in central Spain.

Baseline data on the insect successional patterns on carcasses can be a valuable estimation tool in the investigations of suspicious deaths, particularly when the post-mortem interval is longer than months or years. However, although carrion insect succession is a recurrent topic in forensic science research, the duration of the published studies is typically shorter than 1 year, with only one published study from central Europe documenting successional patterns beyond the first year of decomposition. We provide here the first data on the long-term insect successional patterns in southern Europe, using pig carcasses exposed in the four seasons of the year and documenting the carrion entomofauna during the second and third year of decomposition.

Larval identification key to necrophagous Coleoptera of medico-legal importance in the western Palaearctic.

Several necrophagous Coleoptera species are frequently collected on cadavers, may occasionally act as intermediate or paratenic hosts of parasites, as vectors of pathogens or as allergens, and can also represent major pests of preserved animal products. However, despite their medical, veterinary and economic importance, there is a lack of reliable species identification tools for the larval stages (usually the only entomological evidence associated with medicolegal investigations), thus severely limiting their potential application as forensic indicators. Here, we provide an identification key to the larvae of the necrophagous Coleoptera species which have been recorded on carrion in the western Palaearctic region, based on easily observable morphological characters.

3D virtual histology at the host/parasite interface: visualisation of the master manipulator, Dicrocoelium dendriticum, in the brain of its ant host.

Some parasites are able to manipulate the behaviour of their hosts to their own advantage. One of the most well-established textbook examples of host manipulation is that of the trematode Dicrocoelium dendriticum on ants, its second intermediate host. Infected ants harbour encysted metacercariae in the gaster and a non-encysted metacercaria in the suboesophageal ganglion (SOG); however, the mechanisms that D.

Micro-computed tomography visualization of the vestigial alimentary canal in adult oestrid flies.

Oestrid flies (Diptera: Oestridae) do not feed during the adult stage as they acquire all necessary nutrients during the parasitic larval stage. The adult mouthparts and digestive tract are therefore frequently vestigial; however, morphological data on the alimentary canal in adult oestrid flies are scarce and a proper visualization of this organ system within the adult body is lacking. The present work visualizes the morphology of the alimentary canal in adults of two oestrid species, Oestrus ovis L.

Early colonisation of urban indoor carcasses by blow flies (Diptera: Calliphoridae): An experimental study from central Spain.

Due to their ubiquity and synanthropy, blow flies (Diptera: Calliphoridae) are generally the first colonisers of cadavers and, therefore, frequently used to estimate a minimum post-mortem interval (PMI). Whereas in outdoor situations blow flies are expected to locate and colonise exposed cadavers within hours or even minutes after death, it is usually assumed that the colonisation of a cadaver indoors might be delayed for an uncertain period of time. This uncertainty severely limits the informativity of PMI estimates based on entomological evidence.

Effect of Temperature on the Survival and Development of Three Forensically Relevant Dermestes Species (Coleoptera: Dermestidae).

Most Dermestes species (Coleoptera: Dermestidae) are scavengers during both larval and adult stages, with a preference for dry organic matter. Because of this, Dermestes beetles are potentially useful indicators in forensic investigations concerning skeletonized and mummified human remains. However, there is a paucity of reference developmental data on most forensically relevant Dermestes species.

Age estimation during the blow fly intra-puparial period: a qualitative and quantitative approach using micro-computed tomography.

Minimum post-mortem interval (PMI) estimates often rely on the use of developmental data from blow flies (Diptera: Calliphoridae), which are generally the first colonisers of cadavers and, therefore, exemplar forensic indicators. Developmental data of the intra-puparial period are of particular importance, as it can account for more than half of the developmental duration of the blow fly life cycle. During this period, the insect undergoes metamorphosis inside the opaque, barrel-shaped puparium, formed by the hardening and darkening of the third instar larval cuticle, which shows virtually no external changes until adult emergence.