Dipteran Larvae Research Articles

Biology, ecology, and taxonomy of the parasitoids of the families of Austroniidae, Peradeniidae, Proctorenyxidae, Roproniidae, and Vanhorniidae (Hymenoptera: Proctotrupoidea)

Proctotrupoidae are koinobiont endoparasitoids of holometabolous insect larvae. Although Proctrotrupidae can be common and readily collected by sweep netting or Malaise traps, the superfamily is poorly known biologically. Proctotrupoidae are parasitoids of Coleoptera and, to a lesser extent, Diptera larvae, with one extraordinary host record from a centipede, whereas Heloridae has been reared from Neuroptera larvae. Extralimital families attacking Coleoptera and Neuroptera (Austroniidae, Peradeniidae, Proctorenyxidae) are biologically unknown. This work studies the biology, ecology, and taxonomy of the parasitoids of the Families of Roproniidae, Vanhorniidae, Austroniidae, Proctorenyxidae and Peradeniidae (Hymenoptera: Proctotrupoidea). In terms of the type of research source, we worked with scientific articles published in national and international journals. This modality of production, in addition to being commonly the most valued in the set of bibliographic production, is the most easily accessed. Access to articles was through virtual libraries such as Scielo, the University of São Paulo, Latin American Literature, and the University of Brasilia. This library has a specific section for Hymenoptera, with eight journals and texts of articles available in full. The journals included in this section are the following: Zootaxa, Canadian Journal of Zoology, Proceedings of the Entomological Society of Washington, Memoirs of the American Entomological Institute, Florida Entomologist, Canadian Entomologist, Neotropical Entomology, Cladistics, Journal of Asia-Pacific Entomology, Insect Systematics & Evolution, Journal of Hymenoptera Research. Considering only this section constitutes a limitation of the study since articles belonging to journals that integrate other sections of the aforementioned electronic library could also contribute to the discussion of the production of knowledge about the relationship between hosts and parasitoids. However, in principle, within these articles, there could not necessarily be a discussion focused on biology, ecology, and taxonomy.

Myiasis in Percutaneous Transhepatic Biliary Drainage Site

AbstractThe infection of dipterous larvae causes myiasis. It is generally associated with unsanitary conditions. An interventional radiologist rarely comes across myiasis. We report a case of myiasis around a percutaneous transhepatic biliary drainage (PTBD) tube. A 31-year-old man from a rural area underwent left PTBD for cholangiocarcinoma and was discharged with an internal–external drain. Two weeks later, he presented with pain in the local site, pruritus, and bile leakage. He was found to have maggots around the PTBD tube with poor wound hygiene. Treatment included turpentine oil instillation and oral and topical ivermectin, accompanied by manual removal of the larva.

Expanding the Mesozoic Record of Early Brachyceran Fly Larvae, including New Larval Forms with Chimera-Type Morphologies.

Diptera are one of the four megadiverse groups of holometabolan insects. Flies perform numerous ecological functions, especially in their larval stages. We can assume that this was already the case in the past; however, fly larvae remain rare in most deposits. Here we report new dipteran larvae preserved in Cretaceous (about 99 Ma) Kachin amber from Myanmar and, even older, Jurassic (about 165 Ma) compression fossils from China. Through light microscopy and micro-CT scanning we explore their peculiar morphology and discuss their possible phylogenetic affinities. Several larvae seem to represent the lineage of Stratiomyomorpha. A few others present characters unique to Xylophagidae (awl-flies), as well as to Athericidae (water sniper-flies), resulting in a chimeric morphology. Understanding the exact relationships of most of these specimens with a particular lineage remains challenging, since they differ considerably from any other known dipteran larvae and present some unique traits. Additionally, we report new specimens of Qiyia jurassica Chen et al., 2014, supposedly parasitic larvae, most likely representatives of Athericidae. These new findings offer valuable insights into the evolution of the early diversification of the brachyceran flies and underscore the importance of immature stages in understanding the evolutionary history and ecology of flies.

Riparian invader: A secondary metabolite of Impatiens glandulifera impairs the development of the freshwater invertebrate key species Chironomus riparius

Invasive species represent a significant threat to native biodiversity. The Himalayan Balsam Impatiens glandulifera is an annual plant, which is invasive in Europe and often inhabits the riparian zone. It produces several secondary metabolites causing, for example, growth inhibition of terrestrial plants and invertebrates. One of these metabolites is the quinone 2-methoxy-1,4-naphthoquinone (2-MNQ). The compound gets washed out from the above-ground parts of the plant during precipitation and may then leach into nearby waterbodies. Despite some evidence for the allelopathic effect of plant secondary metabolites on terrestrial invertebrates, little is known about how 2-MNQ affects the survival or development of aquatic dipteran larvae, despite the importance of this functional group in European freshwaters. Here, we investigated the effects of 2-MNQ on larvae of the river keystone species Chironomus riparius in acute and chronic scenarios. The toxicity of 2-MNQ towards the first and the fourth larval stage was determined in a 48-hour acute exposure assay. We show that 2-MNQ has a negative impact on the development, growth and survival of C. riparius. The LC50 of 2-MNQ was 3.19 mg/l for the first instar and 2.09 mg/l for the fourth instar. A ten-day chronic exposure experiment, where the water was spiked with 2-MNQ, revealed that 2-MNQ had a significantly negative impact on larval body size, head capsule size, body weight, development and survival. These results demonstrate the negative impact of the secondary metabolite 2-MNQ from the terrestrial plant I. glandulifera on a crucial macroinvertebrate inhabiting the adjacent stream ecosystem in riverine ecosystems. This may lead to a decline in population size, resulting in cascading effects on the food web.

Зообентос реки Зимней Золотицы в районе месторождения алмазов имени М. В. Ломоносова

22 invertebrate taxons of zoobenthos were found over the entire study period in the Zimnyaya Zolotitsa River at the Lomonosov diamond deposit. The number of sampling points (stations) for monitoring period is 6. The average number of taxons per station for the entire monitoring period is 11, ranging from 3 to 16. Almost annually, larvae of chironomidae were found at all stations in samples; the frequency of them for all stations over the entire monitoring period was 94%. In addition, the mayfly larvae (89%), diptera larvae (85%), оligochaeta (82%) and hydrachna (78%) were the most common. The average value of the Shannon index as a whole on the studied part of the Zimnyaya Zolotitsa river system for the period 2000–2021 amounted to 1.87, varying from 0.76 (the Svetly Creek, 2016) up to 2.9 (the Svetlaya River). The Margalef species wealth index as a whole on the studied part of the Zimnyaya Zolotitsa River was 0.85. The Pielu equalization index averaged 0.58, indicating the presence of dominant taxons in samples. The number of invertebrates on the studied section of the Zimnyaya Zolotitsa River over the years of monitoring varied from 110 to 28375 spec/m2, averaging 5369 spec/m2. The biomass of invertebrates on the studied part of the Zimnyaya Zolotitsa River over the years ranged from 0.026 to 29.060 g/m2, on average – 4.015 g/m2. Despite the lack of negative impact on the river ecosystem, one of the dominant groups in the zoobenthos is оligochaeta, the proportion of which varied from 4.4% at 148 km from the mouth of the Zimnyaya Zolotitsa River up to 24.1% at 152 km. Taking into account the relatively high proportion of oligochetes in benthic samples, an oligochete index was used to assess water quality in the Zimnyaya Zolotitsa River. In general, the Zimnyaya Zolotitsa river system is estimated as pure – the average оligochaeta index for all sampling points for the entire monitoring period was 8%. One-time increases in the оligochaeta index to maximum values suggest a slight contamination of the river based on the index gradation. These increases are likely related to natural processes in the river system, as evidenced by high оligochaeta index values at the upper sampling points (169 km) located outside the deposit area.

Evaluation of blow fly, Chrysomya megacephala (Calliphoridae: Diptera) as an alternate source of protein in broiler feed

Abstract Poultry industry is one of the fastest growing agri-businesses in the world. However, the usage of expensive soybean meal and fishmeal as poultry feed ingredients is making it less profitable and environmentally unsustainable. Insects are becoming more popular as an alternate protein source in poultry feed because they are more sustainable, cost-efficient and eco-friendly than most of the conventional poultry feed sources. In the present study, we replaced 4%, 8% and 12% soybean meal with blow fly, Chrysomya megacephala (Calliphoridae: Diptera) larvae and evaluated its impact on growth performances, hematological parameters, intestinal morphometry and meat quality of Ross 308 broiler. For comparison, we also evaluated commercially available full fat Hermetia illucens (Stratiomyidae: Diptera) larvae. Three hundred and fifty 1-day-old chicks with initial weight of 40.28 g/chick were randomly divided into seven experimental diets (5 pens per treatment and 10 birds per pen). All the dietary treatments were isocaloric and isonitrogenous, meeting the nutrient requirements of the broilers. The results revealed that the broiler fed on 12% C. megacephala or H. illucens had significantly higher () live weight, average daily weight gain and better feed conversion ratios. The diets containing 12% C. megacephala or H. illucens significantly improved the blood haematology and serum bio-chemistry in the broiler. The gut histological indices of jejunum and ileum such as villus height (Vh), crypt depth (Cd), villus width (Vw), and Vh/Cd ratios also improved by the feeding of 12% C. megacephala and H. illucens diets. The broiler fed on 12% H. illucens diet showed higher L* (lightness) and a* (redness), while those fed on 12% C. megacephala showed higher b* (yellowness) in breast meat (Pectoralis major). Both species performed equally well in growth performance, haematology, serum bio-chemistry, gut histology and meat quality. It was concluded that replacement of soybean meal with 12% C. megacephala or H. illucens larvae improves the growth performance, blood haematology, gut histology and meat color and lightness traits of broiler and thus can be used as an alternate source of protein in broiler feed.

Water-filled leaf axils in teasel plants: A study of often overlooked aquatic habitats

Teasels (Dipsacus spp.) are among the few European plant species that can create small aquatic ecosystems, known as phytotelmata, in their leaf axils. However, these unique environments have received little research attention. We performed the first detailed study of phytotelmata in teasels, aiming to describe the physical habitat and macroinvertebrate communities across different leaf axil levels. We explored 64 phytotelmata on 20 teasel plants in Slovakia (Central Europe). These small aquatic ecosystems contained less than 100 ml of water, exhibited a pH ranging from slightly acidic to neutral, had very low oxygen content, and showed highly variable conductivity. We collected more than 1000 larvae of Diptera, representing at least ten aquatic invertebrate taxa. The dominant species found in these communities were the chironomid Metriocnemus eurynotus (Holmgren, 1883), followed by ceratopogonids of the genus Dasyhelea. The oldest, bottom-situated phytotelmata showed the highest invertebrate density and species richness, suggesting an important role of ecosystem age and the probability of colonization in the community assembly process. These highly replicated ecosystems with simple communities may serve as useful models for studying various ecological phenomena such as metacommunity dynamics, succession, community assembly, biodiversity-ecosystem functioning or mutualistic interactions.

Influence of carcass mass on decomposition rate: A medico‐legal entomology perspective

AbstractBody decomposition is influenced by various factors, including temperature, rainfall, body mass, and the activities of insects and carnivores in areas where carcasses are abandoned. However, the specific impact of carcass mass on the decomposition rate remains unclear. Therefore, this study aimed to compare the effects of carcass mass on decomposition rate with controlled domestic environmental conditions. Carcasses were categorized as small and large. Decomposition patterns were evaluated using a visual scatterplot to illustrate the relationship between total body scores and log accumulated degree days (ADD). To quantitatively compare decomposition rates, a linear regression model was employed to analyze differences between the two carcass groups. Regardless of carcass mass, a similar oviposition period for flies (Diptera) was observed, and the external appearance of the carcass remained relatively stable until 1.8 logADD, marking the emergence of maggots. However, decomposition dramatically accelerated after reaching 1.8 logADD, coinciding with maggots hatching from eggs and their commencement of scavenging. In contrast to larger ones, the hastened decomposition of small carcasses can be attributed to the relatively substantial volume of Diptera larvae within the small carcasses, expediting colonization and utilization. Therefore, carcass mass should factor into postmortem interval estimation based on the degree of body decomposition.

Ability of aquatic Stratiomyidae (Diptera) larvae to survive stream drying using dormancy

To better understand the limitations of dormancy on Odontomyia Meigen, 1803 (Diptera: Stratiomyidae) survival and body condition, we conducted a series of laboratory-based microcosm experiments. We found that Odontomyia larvae can survive at least two extended dry periods (≥30 days) through dormancy. The presence of moisture in the substrate during dormancy is not necessary to survive and had no effect on survival or larval body mass in our experiments. Energy and bodily water loss likely limit survival in dormant stages. Although these results suggest Odontomyia are fairly resistant to drying, more data is needed on body mass, pupation, and reproductive success across hydroregimes. The more we understand about the survival limitations of rock pool aquatic invertebrates, the more successful conservation efforts will be for their unique aquatic biota.

Length-mass allometries of the larvae of aquatic dipterans: differences between taxa, morphological traits, and methods.

Body mass underpins many ecological processes at the level of individuals, populations, and communities. Often estimated in arthropods from linear morphological traits such as body length or head width, these relationships can vary even between closely related taxa. Length-mass relationships of mosquito (Diptera: Culicidae) larvae are poorly known despite the importance of this family to disease and aquatic ecology. To fill this gap, we measured ontogenetic changes in linear traits (body length, head width, and thorax width) and dry and wet masses and estimated length- and width-mass relationships in larvae of 3 culicid species inhabiting different niches: the tropical Aedes albopictus (Skuse, 1894), the temperate Culex pipiens (Linnaeus, 1758), and the snowmelt Ochlerotatus punctor (Kirby, 1837). We compared our results with published length-mass allometries of other aquatic dipteran larvae. We showed that thorax width and body length, but not head width, reliably predicted body mass for our 3 species. The length-mass allometry slopes in aquatic dipterans varied considerably between and within families but were independent of phylogeny, specimen handling, preservation techniques, and data fitting methods. Slope estimates became less precise with decreasing sample size and size range. To obtain reliable estimates of the allometric slopes, we have thus recommended using data on all larval stages for intraspecific allometries and a wide range of species for interspecific allometries. We also cautioned against the indiscriminate use of length-mass allometries obtained for other taxa or collected at lower taxonomic resolutions, e.g., when using length-mass relationships to estimate biomass production at a given site.

A cheia não causou homogeneização taxonômica e funcional da comunidade de Chironomidae (Diptera) em uma planície de inundação neotropical

Abstract: Aim We investigated the hypothesis that flood decreases the taxonomic and functional beta diversity of Chironomidae (Diptera) larvae among floodplain lakes, causing biotic homogenization. Methods We collected benthic samples using a modified Petersen grab in 18 lakes in a flood period (March 2011) and a drought period (September 2011) in the Upper Paraná River floodplain. We compared the taxonomic and functional beta diversity of Chironomidae among lakes in flood and drought periods using a multivariate dispersion analysis (PERMDISP). Results We found similar taxonomic and functional beta diversity of the Chironomidae between hydrological periods. Conclusions We did not find evidence of biotic homogenization due to flood pulse. Our findings suggest other mechanisms besides increasing connectivity and environmental similarity due to flood pulse that may structure the benthic community, such as variation in the identity of flood-tolerant morphospecies across lakes.

The first record of the trace fossils Cochlichnus from the Pennsylvanian continental and marine deposits in the Donets Basin, Ukraine

Sinusoidal trace fossils Cochlichnus anguineus are described for the first time from marine and continental siltstones and sandstones of the Mospyne and Smolyanynivka formations (late Bashkirian, Early Pennsylvanian) in Luhansk Oblast, eastern Ukraine (central Donets Basin). Previously, in Ukraine, Cochlichnus anguineus was recorded in the early Bashkirian Buzhanka Formation of the Lviv Paleozoic Trough. Cochlichnus isp. is known from the Ediacaran of western Ukraine. The studied ichnofossils come from four localities representing sedimentary sequences of shallow marine, lagoonal, and lacustrine terrigenous rocks. The ichnogenus Cochlichnus Hitchcock, 1858 is known from the Precambrian to Holocene and were generally distributed in non-marine environments in the Carboniferous, although it has been recorded in a wide range of environments, from lacustrine (Mermia Ichnofacies) to marine (Cruziana Ichnofacies). In the Pennsylvanian deposits of eastern Ukraine, these trace fossils are predominantly found in lacustrine black shales, but also in lagoonal siltstones and shallow marine sandstones and siltstones. Cochlichnus has been interpreted as traces of grazing, feeding, and locomotion, and it is suggested that traces, depending on the environmental conditions and potential producers, may be combinations of all these ethological categories. Potential producers of Cochlichnus include worms sensu lato, as well as nematodes, annelids, insect larvae, or cyclostomates. In modern freshwater basins, traces morphologically similar to Cochlichnus are produced by nematodes and dipteran larvae. It seems that nematodes and/or annelids are the most likely producers of the studied Cochlichnus, since representatives of Diptera are not known in the Carboniferous. In the Donets Basin, Cochlichnus anguineus usually co-occurs with the trace fossils Lockeia, Planolites, and Palaeophycus. Sometimes these ichnofossils are found on the layer surfaces bearing microbially induced sedimentary structures together with Taphrhelminthopsis and Aulichnites.

How to store a beetle larva? Comparing temporal effects of common fluid preservation methods on color, shape, and DNA quality.

Proper fixing and long-term preservation of entomological evidence are essential in collections and research and crucial in applied fields such as forensic entomology. Incorrectly stored samples may lose important morphological features over time, rendering molecular analyses exceedingly difficult. The most effective method for preserving soft samples such as larvae is fluid preservation. It uses a combination of a wide range of fixatives and storage fluids. However, very little comparative work has been done to determine the effects of long-term storage on sample quality in terms of color, shape, and DNA stability. Moreover, the current golden standard in forensic entomology has been tailored for age estimation of larvae of Diptera, which differ from larvae of Coleoptera in morphology and subsequently in applied methods. We compared the effects of combinations of 6 commonly used fixatives and 6 commonly used storage fluids on midsized larvae of the forensically important beetle, Necrodes littoralis (Linnaeus, 1758), in terms of color, shape, and suitability for DNA analyses over a 2-yr period. We were looking for combinations that can preserve specimens in a satisfactory state, can be used on a regular basis, do not require advanced protection or skills of the personnel, and are not toxic or too harmful to the environment. We found not only several methods that scored significantly better in the tested parameters compared with the golden standard but also several common methods that should be avoided. The effects of agents on each tested category are discussed in detail.

Ecotoxicological Effects of Sodium Metasilicate on Two Hydra Species, Hydra viridissima Pallas, 1766 and Hydra oligactis Pallas, 1766

Sodium metasilicate (SM) is a synthetic hazardous water-soluble salt used in industry as an active ingredient in household cleaning products. The impact of SM on the aquatic environment has been discussed worldwide, but its toxicity has not been well documented and researched. Studies have only been performed on a handful of aquatic organisms: algae, plants, blackworms, water fleas, dipteran larvae, and two fish species. Hydra is a simple freshwater cnidarian with diploblastic organisation, where all the cells are in permanent contact with the surrounding aqueous media, and represents a sensitive model organism for environmental toxicity assessments. This research aimed to determine and compare the effect of SM on the morphology, excitability, and behaviour of green and brown hydra and endosymbiotic microalgae as a microbiome of green hydra. The hydras were treated with four sublethal SM concentrations (0.050, 0.365, 0.380, and 0.390 g/L) for 72 h. Standard preparations were made for the cyto-histological analysis of green hydra, and damaged cellular layers and mesoglea and a changed distribution of microalgae were recorded. The SM caused muted responses to mechanical stimuli and damage to the tentacles in both hydra species. The changes were more pronounced in brown hydra, while green hydra showed better adaptability to unfavourable environmental conditions.

Diet composition of a native fish species in a neotropical lentic environment

Native species are important to the dynamics of aquatic environments. Studies that seek to understand the basic biology of these species provide information on the species and the dynamics of the natural environment. We characterized the diet, feeding habits, and trophic niche breadth of the native species Hoplosternum littorale (Hancock, 1828) in neotropical lentic environments. Collections were carried out in July 2018 at two sampling points (lagoons) located in the São Francisco Falso River and the Corvo River using gill nets. Stomach content was analyzed, and food items were separated, identified, and quantified using the volumetric method. PERMANOVA analysis was performed to evaluate possible differences in diet between the lagoons. Furthermore, PERMDISP was used to test the trophic niche breadth. Fifteen food items were recorded in the São Francisco lagoon, with the most consumed items being detritus, Diptera (larvae and pupa), and Odonata (nymph). Seven food items were recorded in the Corvo lagoon, with detritus being the most consumed. There was no difference in diet composition and trophic niche breadth between the evaluated lagoons. For both lagoons studied, the species was determined to be a detritivore feeding habit, given its diet's predominant consumption of detritus. The detritivore classification may be related to environmental conditions, food availability, and functional morphology. We also observed the presence of microplastics in the stomachs of some specimens, demonstrating anthropic influence on aquatic environments. Our study contributes to bettering knowledge on this species, and consequently the conservation of the species. It can also serve as a basis for conducting future scientific studies, along with developing the area of study related to Brazilian fish ecology.

Biology, ecology, and taxonomy of the parasitoids of the families Austroniidae, Peradeniidae, Proctorenyxidae, Roproniidae, and Vanhorniidae (Hymenoptera: Proctotrupoidea) and family Mymarommatidae (Hymenoptera: Proctotrupomorpha: Mymarommatoidea)

The Proctotrupoidea are koinobiont endoparasitoids of holometabolous insect larvae. Although Proctotrupidae can be common and readily collected by sweep netting or Malaise traps, the superfamily is poorly known biologically. Proctotrupidae is parasitoids of Coleoptera and, to a lesser extent, Diptera larvae, with one extraordinary host record from a centipede, whereas Heloridae has been reared from Neuroptera larvae. Extralimital families attacking Coleoptera and Neuroptera (Austroniidae, Peradeniidae, Proctorenyxidae) are biologically unknown. The hosts of the Mymarommatidae family are poorly known. One species was bred in “wood ear” fungi. Little is known about the biology of these wasps, but they are probably parasitoids of eggs of other insects in forests. Mymaromma menehune Honsberger & Huber, 2022 recorded as a solitary endoparasitoid of eggs of a Lepidopsocus sp. (Psocodea: Lepidopsocidae) on branches of Ficus microcarpa L.f. (Moraceae). This work studies the biology, ecology, and taxonomy of the parasitoids of the families of Austroniidae, Peradeniidae Proctorenyxidae, Roproniidae, and Vanhorniidae (Hymenoptera: Proctotrupoidea) and family Mymaromatidae (Hymenoptera: Proctotrupomorpha: Mymarommatoidea). In terms of the type of research source, we worked with scientific articles published in national and international journals. This modality of production, in addition to being commonly the most valued in the set of bibliographic production, is the most easily accessed. Access to articles was through virtual libraries such as SciELO, the University of São Paulo, Latin American Literature, and the University of Brasilia. This library has a specific section for Hymenoptera, with eight journals and texts of articles available in full. Considering only this section constitutes a limitation of the study since articles belonging to journals that integrate other sections of the fore mentioned electronic library could also contribute to the discussion of the production of knowledge about the relationship between hosts and parasitoids. However, in principle, within these articles, there could not necessarily be a discussion focused on biology, ecology, and taxonomy.

Bacteria in digestive tract of Simuliidae (Insecta: Diptera) larvae from the Brazilian Amazon

Simuliidae are known to be vectors of tropical diseases, as well as the transmission of viruses, bacteria and protozoa. The objective of the study was to isolate and identify bacteria from the digestive tract of larvae from breeding sites in several municipalities in the Amazon, especially in the States of Amazonas and Rondônia. Larvae were collected using tweezers and stored in sterile tubes under refrigeration. In the laboratory, a total of 210 larvae were dissected under aseptic conditions and then bacterial isolation, multiplication and characterization were carried out. Specific identification was based on the 16S ribosomal DNA method, complemented with biochemical tests (BBL Crystal, BBL and Bactray System, Laborclin). A total of 58 bacterial isolates were obtained and the representative genera in the larvae of 7 Simuliidae species analyzed were Bacillus, Staphylococcus, Haphinia, Chromobacterium and Escherichia. Knowledge about the bacterial diversity of insects can contribute both to a better understanding of host-microorganism relationships and to the search for bacterial species for use in biological control programs for insect vectors of diseases or agricultural pests.

DNA damage and molecular level effects induced by polystyrene (PS) nanoplastics (NPs) after Chironomus riparius (Diptera) larvae

In this work, we analyzed the early molecular effects of polystyrene (PS) nanoplastics (NPs) on an aquatic primary consumer (larvae of Chironomus riparius, Diptera) to evaluate their potential DNA damage and the transcriptional response of different genes related to cellular and oxidative stress, endocrine response, developmental, oxygen transport, and immune response. After 24-h exposures of larvae to doses of PS NPs close to those currently found in the environment, the results revealed a large genotoxic effect. This end was evidenced after significant increases in DNA strand breaks of C. riparius larvae quantified by the comet assay, together with results obtained when analyzing the expression of four genes involved in DNA repair (xrrc1, ATM, DECAY and NLK) and which were reduced in the presence of these nanomaterials. Consequently, this reduction trend is likely to prevent the repair of DNA damage caused by PS NPs. In addition, the same tendency to reduce the expression of genes involved in cellular stress, oxidative stress, ecdysone pathway, development, and oxygen transport was observed. Taken together, these results suggest that PS NPs reduce the expression of hormonal target genes and a developmental gene. We show, for the first time, effects of PS NPs on the endocrine system of C. riparius and suggest a possible mechanism of blocking ecdysteroid hormones in insects. Moreover, the NPs were able to inhibit the expression of hemoglobin (Hb C), a protein involved in oxygen transport, and activate a gene of the humoral immune system. These data reveal for the first time the genomic effects of PS NPs in the aquatic invertebrate C. riparius, at the base of the food chain.

Soluble phenols in litter are reduced during passage through the soil macrofauna gut due to the formation of insoluble complexes with proteins: A case study with isopods and Diptera larvae

Plant litter represents a major source of soil organic matter and hence understanding the pathway of its decomposition and stabilisation is crucial for understanding the soil carbon dynamic. Importantly, more than half of annual litter production is consumed by soil fauna globally. Here we test the hypothesis that soluble phenols can be removed from the litter during gut passage and bound on nitrogen rich compounds, which results in formation of insoluble complexes in the faeces produced by soil fauna. Two invertebrate species, Diptera larvae Bibio marci and terrestrial isopod Armadilidium vulgare, and litter of two tree species, Quercus robur and Alnus glutinosa, were used. Both species of invertebrates were fed by both litter types in full factorial manner. The litter contained significantly more free phenols than the faeces. In opposite, the content of bound phenols was significantly higher in faeces than in the litter. The loss of total nitrogen associated with removal of bound phenolic compounds from faeces was higher than that of the litter. Thus, soil fauna contributes to the stabilisation of soil organic matter by the conversion of soluble phenols to insoluble ones together with nitrogen immobilization. In conclusion, this process of stabilisation likely plays an important role in mature soils where mineral surfaces have reached carbon saturation or in soils with higher organic horizons.

Aural myiasis by Sarcophagidae in a pediatric patient: A case report and literature review

Introduction: Physicians often treat patients in the urgent and non-urgent settings who present with various types of foreign bodies lodged in the external auditory canal (EAC). This can cause significant distress to the patient, as well as the caregiver in pediatric cases. Typically, these objects are inanimate and include beads, rocks, toys, craft supplies, food particles, and jewelry. However, sometimes the patient will present with biotic organisms in the ear that seem to cause considerably more distress and damage, including otalgia and otorrhea from abrasions to the EAC, or damage to the tympanic membrane. These creatures can present alive or dead in the EAC. The culprits can include crawling and flying species. However, even rarer, the larval stages have been reported. When an ear is infested by Diptera larvae, the juvenile stage of a fly, the parasitosis is known as aural myiasis. Case Report: In this case, a 7-year-old boy in acute distress presented to the emergency department with left ear otalgia and pruritis. His ear canal was covered in dried blood, and he was found to have 15–20 maggots belonging to the Sarcophagidae family in the left EAC that were removed via lidocaine application and normal saline irrigation. Conclusion: The patient and his caregivers were educated on hygienic practices and advised on outpatient follow-up. Further research is indicated for best practices treating aural myiasis and establishing environmental risk factors.