Dipteran Larvae Research Articles

A first record of a suspected intestinal myiasis caused by Muscina stabulans (Fallén 1817) (Diptera: Muscidae) in Southern South America.

We report a case of a suspected intestinal myiasis of a child from Southeast Argentina. Diptera larvae were sampled by a physician from the nappy worn by the child and submitted for examination and identification to the Laboratorio de Artrópodos (Universidad Nacional de Mar del Plata). Based on diagnosis of the anterior and posterior spiracles and mouthparts, the larvae were identified as the false stable fly Muscina stabulans (Fallén, 1817) (Diptera: Muscidae). A comparison of diagnostic characters between Argentinean and European third instars of this species is presented. Muscina stabulans is a prevalent species in the district of General Pueyrredón, Buenos Aires province, where the case occurred. Its abundance in the area coincidentally peaked at the time of the infestation. This is the 1st report of M. stabulans as a suspect of intestinal myiasis for the whole of the southern cone of South America (Chile and Argentina).

Old World Micropholcus spiders, with first records of acrocerid parasitoids in Pholcidae (Araneae).

Micropholcus Deeleman-Reinhold & Prinsen, 1987 is one of only two Pholcidae genera known to occur both in the Old and New Worlds. However, there are major morphological and ecological differences among geographically separate groups of species, and it was mainly molecular data that have resulted in our current view of uniting all these species into a single genus. In the Old World, only four species have previously been described. Here, current knowledge about Old World Micropholcus is reviewed, redescribing three of the four previously known species, and describing twelve new species, originating from Saudi Arabia (M.dhahran Huber, sp. nov., M.harajah Huber, sp. nov., M.alfara Huber, sp. nov., M.abha Huber, sp. nov., M.tanomah Huber, sp. nov., M.bashayer Huber, sp. nov., M.maysaan Huber, sp. nov.), Oman (M.darbat Huber, sp. nov., M.shaat Huber, sp. nov.), Morocco (M.ghar Huber, sp. nov., M.khenifra Huber, Lecigne & Lips, sp. nov.), and the Philippines (M.bukidnon Huber, sp. nov.). We provide an exploratory species delimitation analysis based on CO1 barcodes, extensive SEM data, and first records of Acroceridae (Diptera) larvae in Pholcidae, extracted from book lungs.

Ecological drivers of carrion beetle (Staphylinidae: Silphinae) diversity on small to large mammals.

Silphinae (Staphylinidae; carrion beetles) are important contributors to the efficient decomposition and recycling of carrion necromass. Their community composition is important for the provision of this ecosystem function and can be affected by abiotic and biotic factors. However, investigations are lacking on the effects of carrion characteristics on Silphinae diversity. Carrion body mass may affect Silphinae diversity following the more individuals hypothesis (MIH). The MIH predicts a higher number of species at larger carrion because higher numbers of individuals can be supported on the resource patch. Additionally, biotic factors like carrion species identity or decomposition stage, and the abiotic factors elevation, season and temperature could affect Silphinae diversity. To test the hypotheses, we collected Silphinae throughout the decomposition of 100 carcasses representing 10 mammal species ranging from 0.04 to 124 kg. Experimental carcasses were exposed in a mountain forest landscape in Germany during spring and summer of 2021. We analysed Silphinae diversity using recently developed transformation models that considered the difficult data distribution we obtained. We found no consistent effect of carrion body mass on Silphinae species richness and, therefore, rejected the MIH. Carrion decomposition stage, in contrast, strongly influenced Silphinae diversity. Abundance and species richness increased with the decomposition process. Silphinae abundance increased with temperature and decreased with elevation. Furthermore, Silphinae abundance was lower in summer compared to spring, likely due to increased co-occurrence and competition with dipteran larvae in summer. Neither carrion species identity nor any abiotic factor affected Silphinae species richness following a pattern consistent throughout the seasons. Our approach combining a broad study design with an improved method for data analysis, transformation models, revealed new insights into mechanisms driving carrion beetle diversity during carrion decomposition. Overall, our study illustrates the complexity and multifactorial nature of biotic and abiotic factors affecting diversity.

First Molecular Diagnosis of Oestrus ovis (Linnaeus, 1758) Larvae Causing Conjunctival Ophthalmomyiasis in Mexico City, Mexico.

Human ophthalmomyiasis is a rare ocular parasitosis that results from the accidental infestation of dipteran larvae of several species, including Oestrus ovis (Linnaeus, 1758). This study aims to present the fourth documented human case of ophthalmomyiasis in Mexico, identifying the etiological agent through morphological and molecular analyses. Additionally, we investigated the phylogenetic position and genetic distances among different specimens globally characterized based on mitochondrial Cox1 sequences. A total of five larval specimens were extracted from the patient's eye, with two specimens allocated for identification based on morphological features using a stereomicroscope, and the remaining three preserved in absolute ethanol, one of them used for subsequent analysis using molecular methods. The mitochondrial Cox1 region was amplified and sequenced using automated Sanger sequencing. The resulting sequence was deposited in GenBank under accession number OR440699 and subjected to BlastN analysis against 35 other Cox1 sequences of O. ovis from GenBank. The identity and phylogenetic position of the strains were further explored using parsimony and maximum likelihood phylogenetic methods. Morphological examination of the larval specimens extracted from the patient's eye unequivocally identified them as O. ovis species. BlastN analysis and comprehensive phylogenetic investigations involving a total of 36 Cox1 sequences confirmed the taxonomic identity of the larvae. Notably, our sequence was positioned within the cluster formed by the Brazilian and two Iranian samples. This finding underscores a shared genetic ancestry among these distinct geographical isolates and provides valuable insights into the evolutionary relationships within O. ovis populations. The presence of O. ovis infestation in Mexico City suggests potential shifts in environmental conditions favoring fly proliferation, highlighting the need for vigilance in urban healthcare settings.

Soil fauna changing in after‐pine harvesting's areas along a temporal gradient of Atlantic Forest regeneration

AbstractMonoculture of pine alters the soil fauna community structure, but forest farms, mixed with natural areas, are restoring the original vegetation to protect, the diversity and ecosystem functions. In restoration initiatives it is necessary to consider the soil fauna. Thus, the aim of this study was to investigate how the process of restoration of the soil community occurs over time in areas after pine harvesting. Areas in natural regeneration with 4 and 10 years, pine plantations adjacent to these areas (representing previous use), and areas of natural forest (reference) were evaluated, it was evaluated three areas per treatment, with six sampling points spaced 30 m apart, totalling 18 sampling points for each treatment (n = 18). Soil mesofauna and macrofauna were collected through soil monoliths and pitfall traps. The comparison of the statistical analysis was to check for changes in the soil fauna over time (4 and 10 years) compared with that observed in secondary forest areas. The study showed that, along the natural regeneration time (4 and 10 years), it was observed increments in the diversity and evenness of the soil community and a reduction in the dominance of groups like Formicidae and increases in the community structure complexity with the resurgence of micropredators/regulators (Collembola and Acari), litter transformers (Oligochaeta, Diplopoda, Blattodea, Coleoptera (Larva), Diptera (Larva) and Coleoptera) and predators (Pseudoscorpiones, Opiliones, Symphyla and Coleoptera) after 10 years of natural regeneration, the areas have already recovered groups with important ecosystem functions, but are not yet at the level of abundance, functional diversity and community structure of native forest areas. The 4‐ and 10‐year regeneration areas present major number of soil fauna groups of native forest (20 groups in regeneration areas and 17 in the native forest areas). Even so, the forest showed a major complexity of soil fauna community structure, evidenced by the diversity. This study contributes to the understanding of natural regeneration for soil fauna along a temporal gradient and these findings can guide the conservation of regional soil fauna diversity.

Трансформация почвенных зооценозов в первый год после рубки леса

Soil macrofauna of primary forests of the middle taiga is characterized by high abundance (94.6–146.6 ind./m2), taxonomic richness (10–14 taxa), dominance of Diptera and Cantharidae larvae, similarity of fauna composition (J=0.60–0.65), with a ratio of detritivores and predators equal to 1:1, aggregated or random horizontal distribution. The total density of invertebrates sharply decreases (4.5–26.8 ind./m2) in the first year after deforestation. Some taxa are eliminated from the fauna, 4–7 taxa are remained. The ratio of trophic groups is changed. The distribution of invertebrates in space is disturbed. Soil macrofauna of clear-cutting areas (CCA) retains a taxonomic structure close to the control sites (C). The taxonomic and trophic structure of soil macrofauna is more disturbed on the logging corridors (LC) with three (3LC) and ten (10LC) penetrations of aggregate equipment, recultivated (RLC) and main (MLC) logging corridors. Thus, the density of Diptera larvae is high on the logging corridors. The above are temporary r-strategists characteristic for the disturbed environment. And the ratio of detritivores and predators on the technological sites “C – CCA – 3LC – 10LС – RLC – MLC” is 1:1 – 3:1 – 7:1 – 10:1 – 13:1 – 15:1. A trend towards an increase in the density of detritivores on the recultivated (RLC) and main (MLC) logging corridors was noted. The decrease of the total density of macrofauna and the declining of systematic groups of the clear-cutting areas is not so significant due to the fact that the litter on these sites is almost completely preserved after felling. The low diversity of soil macrofauna on the logging corridors can be explained by a change in the natural conditions for the existence of invertebrates due to the compaction of the upper soil horizons, the partial disappearance of the litter, the appearance of a mineralized soil layer as top horizon, and a rapid change in humidity. Significant changes in the abundance, composition, and ratio of trophic groups of invertebrates indicate the collapse of soil macrofauna, the loss of important groups of destructors and predators from food webs, and a decrease in the quality of their functions at the initial stage of restorative succession, in the first year after deforestation.

Invertebrate diversity in groundwater-filled lava caves is influenced by both neutral- and niche-based processes.

Understanding which factors shape and maintain biodiversity is essential to understand how ecosystems respond to crises. Biodiversity observed in ecological communities is a result of the interaction of various factors which can be classified as either neutral- or niche-based. The importance of these processes has been debated, but many scientists believe that both processes are important. Here, we use unique ecosystems in groundwater-filled lava caves near Lake Mývatn, to examine the importance of neutral- versus niche-based factors for shaping invertebrate communities. We studied diversity in benthic and epibenthic invertebrate communities and related them to ecological variables. We hypothesized that if neutral processes are the main drivers of community structure we would not see any clear relationship between the structure of community within caves and ecological factors. If niche-based processes are important we should see clear relationships between community structure and variation in ecological variables across caves. Both communities were species poor, with low densities of invertebrates, showing the resource limited and oligotrophic nature of these systems. Unusually for Icelandic freshwater ecosystems, the benthic communities were not dominated by Chironomidae (Diptera) larvae, but rather by crustaceans, mainly Cladocera. The epibenthic communities were not shaped by environmental variables, suggesting that they may have been structured primarily by neutral processes. The benthic communities were shaped by the availability of energy, and to some extent pH, suggesting that niche-based processes were important drivers of community structure, although neutral processes may still be relevant. The results suggest that both processes are important for invertebrate communities in freshwater, and research should focus on understanding both of these processes. The ponds we studied are representative of a number of freshwater ecosystems that are extremely vulnerable for human disturbance, making it even more important to understand how their biodiversity is shaped and maintained.

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 a Backyard Pig: A Case Report

Background: Myiasis is a parasitic infestation of livestock animals caused by dipteran larvae. The presence of wounds, lack of hygiene on the farm, and temperate climatic conditions contribute to myiasis. Swine can be infested by myiasis if injured pigs are not treated properly and failure to treat myiasis in time may cause the culling or death of the pigs, resulting in huge economic loss to the farmers. But like humans and other farm animals, pigs also deserve to be treated and cured of any suffering or disease. Therefore, this study is documented on pig myiasis and its management because to date a few cases have been reported on it. Case presentation: This case report documented the successful management of neck myiasis in a male, 9-month-old, 12-kg-weighing backyard pig. The wound site was cleaned using antiseptics and maggots were removed. The site was treated with turpentine oil, and ivermectin at 0.2 mg/kg B.W. and S/C. A combination of streptomycin (12.5 mg/kg B.W.) and penicillin (20000 IU/kg B.W.) was used IM daily for 5 days to prevent secondary bacterial infection. The wound was dressed regularly on every alternate day until the complete removal of maggots and the formation of granulation tissue. Conclusion: Through proper therapeutic management, the backyard pig’s neck myiasis wound was successfully healed in 10 days without any complications.

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.