Evolutionary profile of the family Calliphoridae, with notes on the origin of myiasis

Origins and Diversification of Myiasis Across Blowflies

Parasitism represents a prevalent and successful ecological strategy that has evolved independently numerous times across metazoa. Understanding the origin and diversification of parasitism is a central question in evolutionary biology. This study investigated the evolutionary path leading to a specific form of parasitism in blowflies known as myiasis, where larvae develop on or within a vertebrate. We modeled myiasis-associated traits, including trophic specialization (obligatory parasitism, facultative parasitism and saprophagy), larval food substrate (necrotic, fresh or both) and developmental temperature (constant, variable or both) across the blowfly phylogeny. Our results suggested that the ancestral state of blowflies likely encompassed saprophagy or facultative parasitism, with larvae developing in corpses or necrotic tissues from wounds in either homeothermic or heterothermic hosts. Furthermore, our analysis highlights the role of facultative parasitism as an intermediate step for obligate parasitism in blowflies, indicating that pre-adaptations for a facultative parasitic lifestyle may serve as stepping stones for emerging obligate parasitism. These findings shed light on the complex evolutionary history of blowfly vertebrate parasitism, emphasizing the importance of facultative parasitism as a critical transitional stage in this evolutionary process.

An update on the knowledge and general understanding of the Chilean Diptera diversity

Chilean flies play an important role in many aspects of phylogeny and evolution of Diptera given their uniqueness and direct link with the Gondwanan insect fauna. Many dipterists have considered the order to be one of the most diverse in Chile, but there are still many gaps of information to fill. This study updates the families, genera, and species known from Chile and addresses the evolutionary origin of most dipteran families-indicating which biogeographical layers they belong to. The taxonomic literature was thoroughly reviewed from 1967 until May 2024. Our investigation revealed a total of 97 families, 930 genera and 4,108 valid species, placing Diptera as one of the most specious insect orders in Chile. The diversity of the Lower Diptera (suborders Tipulomorpha, Psychodomorpha, Culicomorpha, Perissommatomorpha and Bibionomorpha) increased to 111 genera (93.27%) and 1,019 species (136.22%), whereas Brachycera increased to 229 genera (48.61%) and 703 species (50.72%). Specifically, the number of genera and species in the division Aschiza increased by 117.14% and 114.28% respectively, while Acalyptratae increased by 62.24% genera and 63.82% species to date. Finally, the number of genera and species in the Calyptratae increased by 31.05% and 50%, respectively. The family Neriidae is newly recorded for Chile and the species Telostylinus lineolatus (Wiedemann) is reported from Easter Island. We present age hypotheses of clades in Chile belonging to 60 families-of which 16 correspond to Cretaceous- and 46 to Cenozoic-, and a small number to Jurassic-elements. Finally, we address three major gaps for a more robust development of Diptera systematics in Chile: (1) lack of long-term systematic sampling, (2) taxonomic, spatial, and temporal biases for Diptera diversity and (3) poor understanding of biological and ecological processes related to Diptera facing advances in anthropogenic impacts across the country.

First report on molecular characterization of Oestrus ovis in sheep from India

The objective of the present study is to characterize the dipteran larvae species infesting the sheep being maintained at SRRC, Mannavanur, by means of COI gene based PCR. During the last week of May 2021, post mortem examination of the skull of an Avikalin male sheep (20 months old) revealed the presence of larvae in its nasal sinuses. The larvae were washed in PBS (pH 7.2) and preserved in 70% alcohol. Total genomic DNA was isolated from the larvae using an initial step of grinding with liquid Nitrogen in a sterile mortar and pestle. Using the isolated genomic DNA from the larvae as a template, Cytochrome c oxidase subunit I (COI) gene based PCR was employed using the primers designed based on the COI gene of reference isolate of Oestrus ovis available in the GenBank. Full length COI gene (1534 bp) gene of Oestrus ovis in sheep from South India was targeted in the PCR experiment. The pTZ57R/T vector was used for the cloning of the PCR amplified fragment and the confirmed recombinant plasmid was subjected to sequencing experiments. In addition to morphological examination, based on COI gene based PCR, eventual sequencing experiments and BLAST analysis, it was confirmed that the larvae in the nasal sinuses of sheep from South India were Oestrus ovis. The South Indian isolate of Oestrus ovis is sharing 100% sequence identity both at nucleotide and amino acid levels with that of O. ovis from Spain. The North Indian isolate of O. ovis (from Jammu) exhibited 92% and 99% identity at respective nucleotide and amino acid levels with South Indian isolate. With other members of the subfamily Oestrinae, the share of per cent nucleotide and amino acid identities of South Indian O. ovis ranged from 85-86% to 95-96%, respectively. O. ovis from South India was grouped with the other members of Oestrinae from different geographical areas of the globe in the analysis of phylogenetic tree based on COI amino acid sequences. Based on the research findings, it is concluded that Oestrus ovis is the dipteran species infesting the sheep at Mannavanur, Tamil Nadu, India. To our knowledge, this is the first report on full length nucleotide sequences of COI gene of O. ovis in sheep from Indian subcontinent.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-024-01666-2.

Review on forensic importance of myiasis: Focus on medicolegal issues on post-mortem interval estimation and neglect evaluation

Myiasis is the infestation of live vertebrates by dipterous larvae that feed on living or necrotic tissues, liquid body substances or ingested food and develop in or on the vertebrate body. In both animals and humans, myiasis plays a fundamental role in forensic practice because of its implications in the evaluation of cases of neglect and in the mPMI (minimum post-mortem interval) estimation. The present study aims to provide a review of forensic issues related to myiasis. A retrospective analysis was conducted by exploring major electronic literature databases. Methodological evaluation of each study was performed according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) standards. Sixty-one papers were included in this review. Entomology shows great potentiality in forensic investigations, mostly because of its contributory role in mPMI estimation. Such evaluation, however, requires a careful consideration of the possibility of an ante-mortem myiasis infestation, which could complicate the correct assessment of the mPMI. Hence, forensic pathologists should pay attention to the entomological fauna on a corpse, in both fresh and decomposed bodies. Moreover, in cases with poor nutritional or hygienic conditions, myiasis should be carefully evaluated as an indicator of neglect.

Invasion of the Land of Samurai: Potential Spread of Old-World Screwworm to Japan under Climate Change

Temperatures have fluctuated dramatically throughout our planet’s long history, and in recent decades, global warming has become a more visible indicator of climate change. Climate change has several effects on different economic sectors, especially the livestock industry. The Old-world screwworm (OWS), Chrysomya bezziana (Villeneuve, 1914), is one of the most destructive insect pests which is invading new regions as a result of climate change. The economic loss in livestock business due to invasion of OWS was previously assessed by FAO in Iraq to be USD 8,555,000. Other areas at risk of invasion with OWS in the future include Japan. Therefore, maximum entropy implemented in MaxEnt was used to model predictive risk maps of OWS invasion to Japan based on two representative concentration pathways (RCPs), 2.6 and 8.5, for 2050 and 2070. The Area Under Curve (AUC) indicates high model performance, with a value equal to 0.89 (±0.001). In addition, the True Skill Statistics (TSS) value was equal to 0.7. The resulting models indicate the unsuitability of the northern territory of Japan for invasion by OWS. The main island’s southern costs show high and very high invasion suitability, respectively, and both Kyushu and Okinawa are at high risk of invasion with OWS. The predicted risk maps can be considered a warning sign for the Japanese quarantine authority to hasten a control program in order to protect the livestock industry from this devastating pest.

Myiasis in humans: Case reports in Northeastern Brazil including multispecies co-infestation by Sarcophagidae

Myiasis is a parasitosis characterized by an infestation of living vertebrates (humans and other animals) by Diptera larvae, whose occurrence and etiological identification are still neglected by health professionals. Here we analyzed the human myiasis cases registered from 2010 to 2018 in health care units in the municipality of Natal, Northeast region of Brazil. Specifically, we aimed to: I) analyze the medical records of cases documented from 2010 to 2017; II) list the patients predisposing factors; and III) monitor the recent cases diagnosed in health units between August 2017 and March 2018 and report the taxonomic identity of the infesting species. Our data revealed that myiases mainly affect the elderly and individuals with predisposing medical conditions (e.g. senility, filariasis). Regarding the new cases, larvae of Calliphoridae (C. hominivorax (Coquerel, 1858)) and Sarcophagidae [Sarcophaga (Liopygia) ruficornis (Fabricius, 1794), Peckia (Sarcodexia) lambens (Wiedemann, 1830), and Helicobia morionella (Aldrich, 1930)] were identified. Furthermore, this was the first report of a co-infestation with three Sarcophagidae species and also the presence of H. morionella in a human wound. These results reinforce that myiasis is an underreported parasitosis, which may underestimate the ability of previously unreported fly species to feed on living human tissues in the Neotropical Region.