Phenotypic polymorphism of Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) may lead to species misidentification

Molecular identification of Chrysomya albiceps (Diptera: Calliphoridae) in a case of primary cutaneous myiasis in sheep at southern Brazil

Sheep farming has been growing in Brazil, driven by an expanding consumer market due to greater acceptance of its meat and derivatives. There are several factors that limit sheep production, and one of them is infestation by ectoparasites, which cause stress in animals, weight loss, poor development, low productivity, low quality wool and reduced fertility. Chrysomya albiceps is a species of blowfly belonging to the Calliphoridae family that occurs in neotropical regions, where it causes secondary myiasis. We identified here a rare case of cutaneous myiasis with the presence of tissue lesions caused by C. albiceps in sheep in southern Brazil. We highlight the need to carry out more in-depth studies regarding the biology of these insects, with the aim of proving this atypical behavior for Brazil.

Simplified COI barcoding of blow, flesh, and scuttle flies encountered in medicolegal investigations

Accurate insect identification is critical to the estimation of time of colonization (TOC) and post-mortem interval (PMI) in medicolegal death investigations. DNA testing is advantageous because it enables the identification of immature specimens that may not be identified based on morphology alone. We describe here a simplified DNA barcoding method for identifying relevant species that may be implemented by forensic genetics laboratories. A cytochrome oxidase (COI) fragment is analyzed after PCR amplification with a single primer set. The method is effective for many species commonly encountered in death investigations in the USA: members of blowfly genera Calliphora, Chrysomya, Cochliomyia, Lucilia, and Phormia; members of the flesh fly genera Blaesoxipha, Oxysarcodexia, Ravinia, and Sarcophaga; and the scuttle fly Megaselia scalaris. We tested the method on specimens with verified identifications and used it to build a collection of reference sequences from specimens collected in Harris County, Texas. We show here the correct identification of larvae, pupae, and pupal exuviae from the medicolegal casework.

Molecular differentiation analysis of ten putative species of Fannia (Diptera: Fanniidae) collected in carrion-baited traps from Colombia

The genus Fannia is the most representative of the Fannidae family of true flies with worldwide distribution. Some species are attracted to decomposing materials and live vertebrate animals, which makes them important in forensics, medical and veterinary fields. However, identifying Fannia species can be difficult due to the high similarity in the external morphology of females and limited descriptions and morphological keys. Herein, molecular markers could provide a complementary tool for species identification. However, molecular identification has still limited application since databases contain few data for neotropical species of Fannia. This study assessed the potential of two molecular markers, the COI-3' region and internal transcribed spacer 2 (ITS2), to differentiate 10 putative species of the genus Fannia from Colombia using distance-based and tree-based approaches. The partial ITS2 and/or COI-3' regions allowed molecular diagnosis of six species, while pairs of species Fannia colazorrensis + F. dodgei and F. laclara + F. aburrae are conflicting. Although these results might suggest that conflicting pair species are conspecific, consistent morphological differences between males do not support this hypothesis. The lack of differentiation at the nuclear and mitochondrial molecular markers for the conflicting species may be due to incomplete evolutionary lineage separation, hybridization, or introgression events. In addition, sexual selection on male morphological traits before species-specific differences in molecular markers emerge may partially explain the results. Our study provides a valuable dataset to identify and confirm some Fannia species molecularly. Further, they could be used to associate females and immature stages with their conspecifics as a baseline to deep into their biology, ecology, distribution and potential applications in forensic and medico-veterinary entomology.

Diversity response of necrophagous dipteran communities and their functional groups to an anthropization gradient

The anthropization process exerts a profound effect on ecosystems, causing alterations in biodiversity, habitat structure, and species composition, ultimately disrupting the delicate balance of natural environments. The aim of the present study was to explore the ecological dynamics of necrophagous Sarcophagidae and Calliphoridae flies along an anthropization gradient. This research investigated alpha and beta diversity patterns to unravel the impact of human-induced environmental changes on these insect communities and also assesses the dynamics of functional groups in relation to their impact on medical and forensic fields. Five distinct habitats, ranging from urban to forested areas, were surveyed in two Departments in the Province of Chaco, Argentina. Necrophagous flies were collected using van Someren-Rydon canopy traps across three seasons. Two main functional groups were analyzed: oviparous flies (Calliphoridae) and larviparous flies (Sarcophagidae). Results indicated a significant negative correlation between Sarcophagidae species richness and anthropization, whereas Calliphoridae showed increased abundance in highly anthropized sites. The combined assemblage of Calliphoridae+Sarcophagidae exhibited significant relationships across all community parameters evaluated. Beta diversity analysis revealed turnover as the main process shaping dipteran communities along the anthropization gradient, with spatial species replacement dominating. This underscores the importance of interspecific spatial segregation in dipteran community composition. In conclusion, this study enhances our understanding of the ecological adaptations of necrophagous dipterans to anthropogenic disturbances. The observed shifts in diversity and abundance have implications for forensic investigations and public health, emphasizing the need for nuanced monitoring and conservation strategies. This research contributes valuable insights into the intricate ecological interactions of these insect communities within changing ecosystems.

A short fragment of mitochondrial DNA for the taxonomic identification of blow flies (Diptera: Calliphoridae) in northwestern South America

Blow flies are of medical, sanitary, veterinary, and forensic importance. Their accurate taxonomic identification is essential for their use in applied research. However, neotropical fauna has not been completely studied or described, and taxa identification without the required training is a difficult task. Additionally, the current morphological keys are not fitting to all extant taxa. Molecular-based approaches are widely used to overcome these issues, including the standard 5' COI barcode fragment (~650 base pairs [bp]) for identification at the species level. Here, a shorter sequence of 5' COI fragment (~342 bp) was assessed for the identification of 28 blow fly species inhabiting the northwest of South America. One tree-based (the generalized mixed Yule-coalescent-GMYC) and 3 distance-based approaches (automatic barcode gap discover - ABGD, the best close match - BCM, and the nearest neighbor - NN) analyses were performed. Noticeably, the amplification and sequencing of samples that had been preserved for up to 57 years were successful. The tree topology assigned 113 sequences to a specific taxon (70% effectiveness), while the distance approach assigned to 95 (59% effectiveness). The short fragment allowed the molecular identification of 19 species (60% of neotropical species except for the Lucilia species and Hemilucilia semidiaphana). According to these findings, the taxonomic and faunistic considerations of the blow fly fauna were provided. Overall, the short fragment approach constitutes an optimal species confirmation tool for the most common blow flies in northwestern South America.

Interactive Key for Third Instar Larvae of Neotropical Blow Flies (Insecta, Diptera, Calliphoridae): the Contribution of Computational Tools to Assist in Species Identification

Calliphoridae (Insecta, Diptera), popularly known as blow flies or carrion flies, as most are necrophagous comprises one of the most relevant families of insects on forensics. Currently, more than 1500 blow fly species are known, the majority of which can be found in the Old World. In the Neotropics, it is estimated that there are approximately 20 species of forensic importance. In view of the taxonomic impediment associated with the identification of immatures, in this study, we present an interactive identification key for third instar larvae of necrophagous Calliphoridae species. This key includes 12 Neotropical blow fly species of forensic importance, more than 70 pictures, schemes, and definitions glossary and is free to access.

Assessment of consistency of minimum post-mortem intervals estimated by thermal summation-based methods in medico-legal cases associated with blowflies

BACKGROUND

This study is based on blow fly samples collected from 8 medico-legal cases in Tamil Nadu, India. The fly life stages were identified and the consistency of minimum post-mortem intervals (PMImin) estimated by different thermal summation-based methods was assessed.

METHODS

PMImin of 8 medico-legal cases was estimated using six different thermal summation constants and lower developmental temperatures that are based on C. megacephala and C. rufifacies developmental data. Limits of agreement (LoA), intra class correlation coefficient (ICC) between PMImin values and margin of error of mean of difference between PMImin values were calculated.

RESULTS

Intra-class correlation between the PMImin values estimated using different thermal summation constants based on C. megacephala ranged between 0.89 and 0.98 and coefficient of determination ranged between 0.93 and 0.98. Intra-class correlation between the PMImin values estimated using different thermal summation constants based on C. rufifacies ranged between 0.91 and 0.99 and coefficient of determination ranged between 0.95 and 0.99. The mean difference of PMImin values estimated using different thermal summation methods based on C. megacephala ranged between 1.8 hr and 6.6hr and margin of error ranged between 2.51 and 6.93hr. The mean difference of PMImin values estimated using different thermal summation methods based on C. rufifacies ranged between 3.33 and 31.33hr and margin of error ranged between 4.66 and 32hr.

CONCLUSION

Consistency of PMImin values estimated by different thermal summation methods was good to excellent. Thermal summation constants useful in estimation of PMImin with lowest mean difference and margin of error were described.

Occurrence of necrophagous flies of forensic importance in medico-legal cases in Tamil Nadu State, India

Background

The present study is based on the necrophagous fly samples collected from 24 medico-legal cases between the year 2011 and 2018 in Tamil Nadu State, India. The fly life stages were identified based on morphological features. Pre-autopsy condition of the human corpse colonized by necrophagous flies and indoor/outdoor occurrence of the flies were recorded.

Results

Chrysomya megacephala, Chrysomya rufifacies, Sarcophaga spp, and Musca domestica life stages were collected from the human corpses. Chrysomya megacephala was the most prevalent (70.8%) insects of forensic importance and found both in indoor and outdoor environments. Drowned and burnt human corpses were found to be only colonized by C. megacephala. Chrysomya rufifacies was found only in outdoor environments and Sarcophaga spp was found only in indoor environment. There was a fair agreement between the percentage occurrence of necrophagous flies in human corpse in the present study in Tamil Nadu State and percentage historical occurrence of necrophagous flies in human corpse in India.

Conclusions

Chrysomya megacephala was the predominant blowfly species found to colonize corpses in Tamil Nadu State, India. Chrysomya megacephala was the only blowfly species found to colonize both burnt and floating corpses and corpses located indoor and outdoor.

Size does matter: intraspecific geometric morphometric analysis of wings of the blowfly Chrysomya albiceps (Diptera: Calliphoridae)

Blowflies have forensic, sanitary and veterinary importance, as well as being pollinators, parasitoids and ecological bioindicators. There is still little work with real data and from experiments assessing the relationship between blowflies' morphologic features and environmental and demographic factors. The present work tests whether the variation, in the shape and size, of Chrysomya albiceps (Wiedemann, 1819) wings is influenced by the following factors: 1) time; 2) temperature; 3) sex and; 4) different types of carcasses (pig, dog/cat and whale). Male and female wings from four different sites collected in six different years were used to obtain wing size and shape of C. albiceps. Analyses between wing shape and the variables tested had low explanatory power, even though they had statistical support. However, it was possible to identify differences in wing shape between males and females, with good returns in sex identification. The comparison between wing size and the variables tested showed that wing size has a negative relationship with temperature, significant differences between sexes, slight variation over time and no influence by carcass types. Furthermore, wing size influenced wing shape. Understanding population-specific characteristics of C. albiceps provide important insights about how the species reacts under specific conditions.

Life Cycle of Chrysomya rufifacies (Diptera: Calliphoridae) Under Semi-Controlled Laboratory Conditions

Adult Calliphoridae flies, as well as their immature stages collected from carcasses, have been used as evidence in forensic investigations to estimate the postmortem interval (PMI), particularly those of the genus Chrysomya as it is one of the first genera to colonize a corpse. Chrysomya rufifacies (Macquart 1842), due to its appearance in cadaveric remains, plays a fundamental role in the study of forensic entomology. For this reason, we determined the biological cycle of C. rufifacies under semicontrolled laboratory conditions: uncontrolled average fluctuating temperature of 29. 76 ± 3. 22°C, uncontrolled average fluctuating humidity of 48. 91 ± 11.13%, and a controlled photoperiod of 12/12 (L/O). We established that the total development time from oviposition to adult emergence of C. rufifacies was 6. 5 d. The eggs took 12 h to hatch after oviposition. The complete larval stage took 60 h (instar 1 = 12 h, instar 2 = 12 h, instar 3 = 24 h, instar 3 post-feeding = 12 h). The pupa had a duration of 84 h. The species needed a total of 4642.8(±4.59) accumulated degree-hours (ADH) to complete its biological cycle.

Blow flies, synanthropy and sex ratio: Are the deviations in the sex proportion linked to human transformation of landscapes?

In most species, several factors like time of emergence, age at maturation, reproductive life span, survival of males and females, mating behavior, differential resource use, and migration patterns may affect the adult sex ratio. Anthropogenic landscape transformation is known to change diversity, favoring colonization by exotic species but other populational parameters, such as the sex ratio, have not been assessed. The aim of the present study was to describe the sex-ratio patterns of adult necrophagous blow flies captured using carrion-baited traps along habitats representing different levels of human impact. We describe the sex bias for four species: the exotic Chrysomya albiceps, Chrysomya megacephala, Chrysomya putoria, and the native Cochliomyia macellaria. Three types of habitats were selected: highly anthropized (urbanized), moderately anthropized (rural), and native forest (natural) within a humid subtropical ecoregion in Northeastern Argentina. We found an overall trend to female bias among the four species when considering the total number of each sex. However, our study showed a changing sex-ratio pattern along the gradient of human influence. Our results indicate that a higher likelihood of trapping more males in unsuitable habitats seems to be widespread among blow flies. Urban exploiters, such as Ch. megacephala and Ch. putoria, locally shifted their trends, becoming male-biased in natural habitats. The opposite trend was detected in the urban avoider Co. macellaria (which shifted to male-biased in urban habitats). The exception was Ch. albiceps, whose sex proportion did not shift to a male-biased sex ratio. The results of this study highlight the changing sex-ratio patterns displayed by Calliphoridae in response to different conditions along a human-influence gradient. The biological traits and underlying mechanisms promoting the intraspecific changes of the sex ratio are discussed.

Body Size and Cuticular Hydrocarbons as Larval Age Indicators in the Forensic Blow Fly, Chrysomya albiceps (Diptera: Calliphoridae)

Chrysomya albiceps (Wiedemann 1819) is one of the most important insects in forensic entomology. Its larval developmental and survival rates are influenced by nutritional resources, temperature, humidity, and geographical regions. The present study investigated the possibility of relying on body size and cuticular hydrocarbon composition as indicators for age estimation of the different larval instars of C. albiceps. Larvae were maintained in standardized laboratory conditions at different experimental temperatures. All larval instars (first, second, and third) were randomly collected for measuring their body sizes and for estimating their cuticular hydrocarbons at different rearing temperatures (30, 35, 40, and 45°C) using gas chromatography-mass spectrometry (GC-MS). Results indicated that the duration of larval stage was temperature dependent as it gradually decreased on increasing the rearing temperature (30, 35, and 40°C) except 45°C at which larval development was ceased. In contrary, larval body size, in terms of length, width, and weight, was temperature dependent as it gradually increased with larval development on increasing rearing temperature except at 45°C at which larval development was ceased. The GC-MS showed a significant difference in the extracted components of cuticular hydrocarbons between different larval instars reared in the same temperature and between the same larval instar that reared at different temperatures. Furthermore, the highest and lowest amounts of cuticular hydrocarbons were detected at 35 and 40°C, respectively. Overall, larval body size and cuticular hydrocarbon components were temperature dependent within the range 30-40°C, which may suggest them as possible reliable age indicators for estimating the postmortem interval in the field of medicolegal entomology.

Gene expression as age estimation marker in the larval stages of the forensic blowfly, Chrysomya albiceps, at different temperatures

The blowfly Chrysomya albiceps (Diptera: Calliphoridae) has been known to breed in both animal and human carcasses in different geographical regions and is considered an important post-mortem indicator in forensic entomology. Determining the age of its larvae is an essential tool for the accurate determination of post-mortem intervals (PMI). This study adopted a molecular-based approach for age determination of the immature stages of the blowfly, C. albiceps, by evaluating the genes 15_2, 2014192, EcdR, AR, hsp90, and Actin, during larval development at different temperatures. Targeted genes were amplified by real-time PCR (RT-PCR), and the resulting amplicons were normalized against the two housekeeping genes, rp49 and 19_2. Data showed that the expression profile of AR was constant throughout all larval developmental stages at all tested temperatures. 2014192 showed low expression levels throughout the 1st, 2nd, and 3rd larval stages. Hsp90 and EcdR showed different expression profiles. The expression of 15_2 was low at the tested temperatures and was undetectable on most days. Collectively, the results of this study indicate that larvae exhibit temperature-dependent and age-specific up- and down-regulation in the expression profile of the targeted genes. This may indicate a possibility to be utilized as age estimation markers for C. albiceps.

Bactericidal Activity of Chrysomya rufifacies and Cochliomyia macellaria (Diptera: Calliphoridae) Larval Excretions-Secretions Against Staphylococcus aureus (Bacillales: Staphylococcaceae)

The inhibitory effect of Chrysomya rufifacies (Macquart) and Cochliomyia macellaria (Fabricius) larval excretions-secretions (ES) on Staphylococcus aureus was determined using a portable colorimetric method without the need for any dedicated spectral instrument. Polystyrene 96 well microplates were used and 100 μl of the bacterial inoculum (5 × 105 CFU/ml) plus 100 μl of the dipteran exosecretions at different concentrations were added to each well. Subsequently, 50 μl of a 1% solution of the triphenyl tetrazolium chloride stain was added to each well to determine the bacterial viability. The color development in each well was measured with the ImageJ software S. aureus was exposed to different concentrations of the ES of both species individually. At a concentration of 800 ppm ES of C. rufifacies or Co. macellaria, bacterial growth was inhibited 97.45 ± 1.70% and 82.21 ± 1.88%, respectively. As expected, exposure to a lower concentration (i.e., 50 ppm) was less inhibitory (C. rufifacies ES, 77.65 ± 4.25% and Co. macellaria ES, 43.54 ± 4.63%). This study demonstrates for the first time the bactericidal activity of C. rufifacies and Co. macellaria ES against S. aureus. This finding is promising as it could result in the identification and synthesis of proteins capable of suppressing pathogen development in wounds. Additionally, the proposed method can simplify the use of expensive laboratory instruments for antimicrobial activity determination.

First molecular phylogeny of Paralucilia Brauer & Bergenstamm, 1891 (Insecta, Diptera, Calliphoridae): A preliminary approach

Paralucilia Brauer & Bergenstamm, 1891 (Diptera, Oestroidea, Calliphoridae) is a small genus of blowflies restricted to the Neotropical region, which is commonly reported on decaying corpses and vertebrate carcasses. The number of species currently assigned to this genus and their denominations are contentious, with either three or five species recognized by different authors. This taxonomic instability results in a lack of consensus in species determination, making it impossible to compare results from different studies as well as to elaborate confident taxonomic keys. In order to solve some of the most commonly reported taxonomic conflicts within this genus, to the best of our knowledge, this study presents the first phylogenetic hypothesis for the relationships among Paralucilia species, based on molecular analysis of the COI, ITS2, 28S, and 16S genes. Maximum parsimony, maximum likelihood, and Bayesian inference analyses were used for phylogenetic reconstruction and divergence time estimation analyses. Intra- and interspecific genetic distances were calculated among species using the COI dataset. The results showed that at least three of the five currently accepted species are well defined: P. fulvinota, P. pseudolyrcea, and P. paraensis, however, a significant level of intraspecific variation was observed in P. fulvinota. These findings will assist future revisions of the description, classification, and distribution of species of Paralucilia, as well as in the elaboration of taxonomic keys. Additionally, we show that it is possible to clarify the evolutionary history of this Neotropical genus using supplementary evidence such as morphology and molecular data.

Calliphoridae (Diptera) in Human-Transformed and Wild Habitats: Diversity and Seasonal Fluctuations in the Humid Chaco Ecoregion of South America

A temporal study of the Calliphoridae fauna was conducted in five different types of habitats in the Humid Chaco ecoregion: an urban settlement, a cattle farm, an alfalfa crop, a savanna, and a forest. Research was carried out to analyze 1) how the species composition of blow fly communities changes across different types of human-modified and wild environments, 2) their seasonal fluctuations, and 3) the influence of climatic factors (relative humidity, temperature, and precipitations) on the temporal dynamics of these communities. In each habitat, five sites were selected for the collection of blow flies using bait traps, and flies were collected for 1 yr. In total, 32,100 blow flies were collected, distributed in five genera and 11 species. The native species Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) was the most abundant, followed by the exotic Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae). The abundance of exotic species represented 59.9% of the total sample, showing a reduction toward less disturbed sites. The Calliphorid communities were compared in terms of species richness, composition, and abundance between habitats and seasons. Our results showed that the habitat type and season affect the composition of blow fly communities. The alfalfa crop and the forest showed the highest diversity of species. In general, there was a decrease in blow fly activity during winter in all habitats. The climatic factors did not greatly affect the diversity of these flies. This study provides a first understanding of several ecological aspects of the Calliphoridae assemblages of the previously unsurveyed Humid Chaco ecoregion of South America.

Forensically Relevant Blow Flies in Lebanon Survey and Identification Using Molecular Markers (Diptera: Calliphoridae)

Calliphoridae are among the first insects associated to decomposing animal remains. We have collected 1,841 specimens of three calliphorid genera: Calliphora, Lucilia, and Chrysomya, from different Lebanese localities as a first step in implementing a database of insects of forensic relevance for the country. Blow-flies are crucial for the estimation of the postmortem interval. DNA-based identification is a rapid and accurate method, often used for morphologically similar species, especially for immatures or incomplete specimens. In this study, we test the suitability of three genetic markers to identify adults and immature stages of calliphorids, viz., mitochondrial cytochrome c oxidase subunit I (COI) barcode, a region including partial sequences of mitochondrial Cyt-b-tRNAser-ND1, and second internal transcribed spacer (ITS2) region of nuclear ribosomal DNA. Forty Lebanese specimens of various developmental stages (egg, larva, wandering third instar, pupa, newly emerged adult, and mature adult) were identified among the three calliphorid genera: Calliphora, Lucilia, and Chrysomya, and compared with published sequences to confirm their specific assignation. Phylogenetic analyses showed the robustness of ITS2 and COI to identify calliphorids at species level. Nevertheless, ITS2 failed to discriminate Lucilia caesar (Linnaeus) (Diptera, Calliphoridae) from Lucilia illustris (Meigen) (Diptera, Calliphoridae), and COI had a similar issue with Lucilia sericata (Meigen) (Diptera, Calliphoridae) and Lucilia cuprina (Wiedemann) (Diptera, Calliphoridae). Thus, these two markers are complementary. This work contributes new nucleotide sequences for Lebanon. It is a first step in implementing a molecular database of forensic relevant insects for the country.

Ultrastructure of male genitalia of blow flies (Diptera: Calliphoridae) of forensic importance

Male genitalia of blow flies (Diptera: Calliphoridae) are distinctive in their morphological features and are often used for species identification. The aim of this work was to investigate the male genitalia of blow flies of medical and forensic importance from Thailand at the ultrastructural level, using scanning electron microscopy (SEM). Flies in two subfamilies were examined: Chrysomyinae [Chrysomya bezziana Villeneuve, Chrysomya chani Kurahashi, Chrysomya nigripes Aubertin, Chrysomya pinguis (Walker), Chrysomya rufifacies (Macquart), Chrysomya thanomthini Kurahashi & Tumrasvin, and Chrysomya villeneuvi Patton] and Luciliinae [Hemipyrellia ligurriens (Wiedemann), Hypopygiopsis infumata (Bigot), Hypopygiopsis tumrasvini Kurahashi, Lucilia cuprina (Wiedemann), Lucilia papuensis Macquart, Lucilia porphyrina (Walker), and Lucilia sinensis Aubertin]. Particular attention was paid to the main distinguishing features such as the shapes of the cercus and the surstylus, and the complex structure of the distiphallus. The differentiation of the male genitalia of these species at the SEM level is discussed and compared to the conditions in closely related species such as Chrysomya megacephala (Fabricius). A key for the identification of 14 blow fly species based on male genitalia is provided.

Seasonal Polyphenism and Behavioral Variations of Ceroplastes glomeratus Peronti (Hemiptera: Coccidae)

The wax scale Ceroplastes glomeratus Peronti shows seasonal behavioral and phenotypic differences. Individuals develop gregariously during autumn, whereas solitarily in spring. Besides such behavioral differences, spring ("isolated form") and autumn ("aggregated form") will also produce different morphotypes. We provide additional data on the morphological data of the species based on the microscopic and macroscopic characteristics of adult females and of first-instars of the two adult morphotypes of C. glomeratus.

Attraction and Oviposition of Lucilia eximia (Diptera: Calliphoridae) to Resources Colonized by the Invasive Competitor Chrysomya albiceps (Diptera: Calliphoridae)

The present study aimed to determine if the presence of immatures of the invasive blow fly species Chrysomya albiceps (Wiedemann) influences the adult behavior of the native species Lucilia eximia (Wiedemann) in Brazil. The level of attraction and oviposition by the native species was assessed in a dual-choice assay. The evaluation was based on sex and stage of ovarian development of L. eximia adults to a resource not colonized (NCR) or colonized (RPC) with eggs, different instars, or densities of C. albiceps. A significant difference in attraction was observed based on sex and stages of ovarian development. Males and nongravid females were more attracted to RPC, whereas gravid females preferred NCR. Moreover, males exhibited the lowest response in all assays among the three sex categories examined. In general, adults preferably oviposited on NCR rather than RPC. Also, between the eggs and second instar treatments, L. eximia laid more eggs on RPC with eggs than second instars (predatory stage). Lucilia eximia attraction to second-instar C. albiceps at different densities was marginally significant. Overall, results indicate the invasive species, C. albiceps, is impacting the behavior of the native blow fly, L. eximia, with regards to its attraction and colonization of vertebrate carrion, which could explain why native blow fly populations have significantly decreased since the introduction of C. albiceps.

Checklist and distribution maps of the blow flies of Venezuela (Diptera, Calliphoridae, Mesembrinellidae)

A checklist of the 39 species of blow flies (Calliphoridae and Mesembrinellidae) so far known to occur in Venezuela is provided, based on a thorough literature review and the examination of ca. 500 specimens deposited in the main entomological collections of the country. Data from the literature and museum collections were used to generate distribution maps for 37 species. Three species are recorded from Venezuela for the first time: Chrysomya putoria (Wiedemann, 1830), Mesembrinella spicata Aldrich, 1925 and Mesembrinella umbrosa Aldrich, 1922.

Distribution and Abundance of Necrophagous Flies (Diptera: Calliphoridae and Sarcophagidae) in Maranhão, Northeastern Brazil

This study aimed at surveying the local calliphorid and sarcophagid species in Maranhão State (Brazil) to determine their distribution and abundance, as well as the distribution of exotic Chrysomya species. In total, 18,128 calliphorid specimens were collected, distributed in 7 genera and 14 species. The species Hemilucilia semidiaphana (Rondani, 1850) and Paralucilia paraensis (Mello, 1969) were new state records. Chrysomya albiceps (Wiedemann, 1819) and Cochliomyia macellaria (F., 1775) were the most abundant species, and the exotic species of Chrysomya together contributed more than 50% of total blow fly abundance. The abundance distribution of the calliphorid community conformed to a log series model, characterized by a steep curve that reflects an assemblage with a high degree of dominance. For the Sarcophagidae, a total of 14,810 specimens were collected and distributed in 15 genera, 11 subgenera, and 52 species. Tricharaea (Sarcophagula) occidua (F., 1794) and Peckia (Sarcodexia) lambens (Wiedemann, 1830) were the most abundant species. The abundance distribution of the species followed a log normal model, with a gentler slope, consistent with a more uniform community. The cumulative species curve for the sarcophagids did not reach the asymptote. Forty-three sarcophagid species were new state records and 22 were new records for the Brazilian northeast, which emphasizes the need for a continued survey in this region.

Species identification of Middle Eastern blowflies (Diptera: Calliphoridae) of forensic importance

The lack of reliable tools for species identification of necrophagous blowflies of the Middle East is a serious obstacle to the development of forensic entomology in the majority of countries of this region. Adding to the complexity of diagnosing the regional fauna is that species representing three different zoogeographical elements exist in sympatry. In response to this situation, a high-quality key to the adults of all species of forensically relevant blowflies of the Middle East has been prepared. Thanks to the modern technique of image-stack stereomicroscopy and high-quality entomological materials, this new key can be easily applied by investigators inexperienced in the taxonomy of blowflies. The major technical problems relating to the species identification of necrophagous blowflies of the Middle East are also discussed.