Larval Types Research Articles

Issue Information

Upper left: Some of the red blood cells (RBCs) in the liver of metamorphic Xenopus laevis express both larval globin (magenta) and the proliferation marker PCNA (green), indicating that larval type cells as well as adult ones (not shown) proliferate during metamorphosis in this species (see Yamaguchi et al. issue 8, pp. 420‐432).Upper middle: in vitro reconstruction of nuclei using Xenopus laevis sperm chromatin and X. laevis (left) or X. tropicalis (right) egg extract. Note that cytoplasmic factors influence the size of reconstructed nuclei consisting of chromatin DNA (magenta) and membrane (green) (see Heijo et al. pp. 501‐507).Upper right: Sox2‐ (green) and radial glia‐like cell marker GFAP‐ (magenta) immunoreactive cells around the lateral ventricle in the adult telencephalon of the newt Cynops pyrrhogaster. This study showed the proliferative and neurogenic zones as well as the fate of proliferated cells in the adult brain, providing a clue to clarify the significance of neurogenesis in adulthood (see Iwasa et al. pp. 474‐485).Middle left: Glucose is considered to act as one of the cryoprotectants in the Japanese tree frog (Hyla japonica) as indicated by a marked elevation of the type 2 glucose transporter (red) expression in the liver of the frozen frog (see Okada et al. pp. 486‐493).Lower left: Dynamic post‐translational modifications of histone H3 during early Xenopus development (see Zhou et al. pp. 508‐516).Lower right: Neurospheres generated from spinal cord cells of the newt Pleurodeles waltl (upper left) expressed the radial glia‐like cell marker GFAP (red) and the neural stem cell marker Nestin (green; weakly) (upper right); or the neural stem cell marker Vimentin (green) and the proliferation marker phospho‐histone H3 (red) (lower left). Cells in the neurosphere differentiated into beta‐III tubulin‐positive neurons (green) and GFAP‐positive astrocytes (magenta) (lower right) (see Seki‐Omura et al. pp. 494‐500). image

Influence of landscape heterogeneity on entomological and parasitological indices of malaria in Kisumu, Western Kenya

BackgroundIdentification and characterization of larval habitats, documentation of Anopheles spp. composition and abundance, and Plasmodium spp. infection burden are critical components of integrated vector management. The present study aimed to investigate the effect of landscape heterogeneity on entomological and parasitological indices of malaria in western Kenya.MethodsA cross-sectional entomological and parasitological survey was conducted along an altitudinal transect in three eco-epidemiological zones: lakeshore along the lakeside, hillside, and highland plateau during the wet and dry seasons in 2020 in Kisumu County, Kenya. Larval habitats for Anopheles mosquitoes were identified and characterized. Adult mosquitoes were sampled using pyrethrum spray catches (PSC). Finger prick blood samples were taken from residents and examined for malaria parasites by real-time PCR (RT-PCR).ResultsIncreased risk of Plasmodium falciparum infection was associated with residency in the lakeshore zone, school-age children, rainy season, and no ITNs (χ2 = 41.201, df = 9, P < 0.0001). Similarly, lakeshore zone and the rainy season significantly increased Anopheles spp. abundance. However, house structures such as wall type and whether the eave spaces were closed or open, as well as the use of ITNs, did not affect Anopheles spp. densities in the homes (χ2 = 38.695, df = 7, P < 0.0001). Anopheles funestus (41.8%) and An. arabiensis (29.1%) were the most abundant vectors in all zones. Sporozoite prevalence was 5.6% and 3.2% in the two species respectively. The lakeshore zone had the highest sporozoite prevalence (4.4%, 7/160) and inoculation rates (135.2 infective bites/person/year). High larval densities were significantly associated with lakeshore zone and hillside zones, animal hoof prints and tire truck larval habitats, wetland and pasture land, and the wet season. The larval habitat types differed significantly across the landscape zones and seasonality (χ2 = 1453.044, df = 298, P < 0.0001).ConclusionThe empirical evidence on the impact of landscape heterogeneity and seasonality on vector densities, parasite transmission, and Plasmodium infections in humans emphasizes the importance of tailoring specific adaptive environmental management interventions to specific landscape attributes to have a significant impact on transmission reduction.Graphical abstract

In situ treatment of juvenile frogs for disease can reverse population declines

AbstractEffective management of wildlife populations threatened by disease requires accurate predictions about the consequences of intervention. However, generating such predictions is challenging, especially for organisms with complex life histories that are also threatened by climate change, such as montane amphibians. Cascades frogs (Rana cascadae) in northern California have experienced dramatic declines associated with the fungal pathogen Batrachochytrium dendrobatidis (Bd), and remnant populations are also threatened by changing climate conditions. We evaluated the population‐level impacts of treating Cascades frog metamorphs with the antifungal chemical itraconazole using a field experiment and population simulations. We explored the influence of larval habitat on these treatment effects by including metamorphs from different larval habitat types. We found that frogs treated with itraconazole were more than four times more likely to survive their first winter than untreated controls and had reduced Bd infection intensity compared to other surviving frogs from the same cohort in the following year. We also found an effect of larval habitat type on Bd infection in recently metamorphosed frogs, with the lowest levels of infection occurring in frogs emerging from larval habitats that tend to be intermediate in temperature and drying rate. Applying the differential apparent overwinter survival of treated and untreated metamorphs to population projections suggests that intermittent antifungal treatment of metamorphs has the potential to restore population viability. Our results indicate that in situ treatment of individual hosts may be a useful component of a comprehensive management strategy to reduce the risk of pathogen‐mediated population declines and extirpations.

Papules, pustules, and rhinoconjunctivitis in a 4-year-old

Papules, pustules, and rhinoconjunctivitis in a 4-year-old

Defining the mechanisms of action and mosquito larva midgut response to a yeast-encapsulated orange oil larvicide

BackgroundYeast-encapsulated orange oil (YEOO) is a novel, ingestible larvicide that combines the benefits of a low-cost essential oil with yeast, an attractive food source for mosquito larvae. In this work, we investigated the underlying mechanisms of action associated with YEOO ingestion by Aedes aegypti larvae.MethodsAedes aegypti third-stage larvae (L3) were treated with sublethal or lethal concentrations of YEOO. Genes associated with apoptosis, autophagy and innate immune responses were investigated by RT-qPCR in guts and carcasses dissected from treated and control larvae. Differential expression of cytochrome P450 genes in the CYP6 and CYP9 families were also investigated. Confocal and transmission electron microscopy were used to assess damage caused by YEOO throughout the larval alimentary canal. TUNEL was used to assess apoptosis via DNA fragmentation.ResultsThe apoptosis genes IAP1 and IAP2 in larvae displayed opposing effects following exposure to lethal doses of YEOO, with a 26-fold induction of IAP1 at 8 h post YEOO ingestion. The effector caspase CASPS8 displayed a 6.7-fold induction in the gut and concomitant 70-fold induction in the carcass at 8 h post YEOO ingestion. The midgut epithelia regenerator, Vein, had an 11-fold induction in the gut after 4 h and was repressed 7.6-fold in the carcass at 24 h. Sublethal concentrations (< LC50) led to significant differential expression of CYP6 and CYP9 genes. Midgut epithelial damage was highlighted by the destruction of microvilli, vacuolization of midgut cells and damage to cell junctions and basal lamina as early as 30 min. Larval type 2 peritrophic matrix structural integrity and porosity remain unchanged.ConclusionOur results strongly suggest that the robust larvicidal activity of YEOO is due to a generalized broad-acting mechanism combining epithelial damage and apoptosis, with concomitant expression of multiple innate response genes involved in epithelial regeneration and detoxification. YEOO’s amenability for use as part of an integrated vector management program makes this novel larvicide a practical approach for mosquito larval control in the future.Graphical

Who can pass the urban filter? A multi-taxon approach to disentangle pollinator trait–environmental relationships

Cities are considered important refuges for insect pollinators. This has been shown repeatedly for wild bees, but may also be true for other diverse taxa such as hoverflies. However, our understanding of how urban environmental filters shape pollinator species communities and their traits is still limited. Here, we used wild bee and hoverfly species, communities and their functional traits to illustrate how environmental filters on the landscape and local scale shape urban species pools. The multi-taxon approach revealed that environmental filtering predominantly occurred at the landscape scale as urbanisation and 3D connectivity significantly structured the taxonomic and functional composition of wild bee (sociality, nesting, diet, body size) and hoverfly (larval food type, migratory status) communities. We identified urban winners and losers attributed to taxon-specific responses to urban filters. Our results suggest that insect pollinator conservation needs to take place primarily at the landscape level while considering species traits, especially by increasing habitat connectivity.

Early lecithotrophic stages of Nymphon grossipes, and the role of larval appendages and glands in different larval types of pycnogonids.

Nymphon grossipes is a common subtidal species belonging to a small and unique group of chelicerates, that is, the sea spiders. These animals have an anamorphic phase during post-embryonic development and often hatch as small, oligomeric and exotrophic larvae (protonymphons) with four postocular segments, cheliphores, and two pairs of larval legs. A common alternative to protonymphons is a large lecithotrophic larval type, where animals hatch at more advanced stages and have a foreshortened anamorphic development. Based on external morphology, N. grossipes was believed to be an intriguing intermediate between these two conditions and its hatchlings were called "lecithotrophic protonymphons." Here, we examine the anatomy and ultrastructure of instars I and II and review the variety of roles of larval appendages and associated glands in other sea spiders in order to correctly place the larva of this species among pycnogonid larval types. Compared to "typical protonymphons," N. grossipes young hatch with an advanced segmental and appendage composition: six postocular segments instead of four, buds of walking legs 1 and hidden buds of walking legs 2. This state corresponds to the instars II/III (rather than larvae) of Nymphon brevirostre and Pycnogonum litorale. Modifications of the larval appendages, chelar, and spinning glands are aligned with ecological needs of different larval types along a few typical dimensions: locomotion and feeding, dispersal, and attachment to the parent. Although the main challenge for N. grossipes young is secure attachment to the egg package while they growth, there are some discrepancies in their anatomy: N. grossipes retains an oyster basket, but an otherwise nonfunctional digestive system, and a strong silken thread for attachment, but no corresponding reduction of the larval legs. Thus, it is likely that the switch to lecithotrophy happened in the recent evolutionary history of this species.

Неолитическая керамика посольского и усть-бельского типов из окрестностей г. Красноярска в фондах Красноярского краевого краеведческого музея

This article presents the Neolithic ceramics of the Ust-Belaya and Posolskaya types from sites in the vicinity of Krasnoyarsk from the funds of the Krasnoyarsk Regional Museum of Local History. These materials were found at the sites of Ust-Sobakino, Bazaikha, Ladeiki, and Nyasha in the 1890s–1920s. During these years, various researchers collected exhibited material, including Neolithic ceramics, and handed it over to the museum's funds. The only excavations of the Neolithic site during this period were carried out in 1929 at Ust-Sobakino by V. Kartsov. Most of the material received was not published. 110 fragments from 29 vessels of the Ust-Belaya type and 12 fragments from 8 vessels of the Posolskaya ones were analyzed. Vessels of the Ust-Belaya type were found at all objects and have a simple closed, rarely open form. The ornament could occupy both the upper part of the vessel and cover it entirely. The rim on the outer side, or on both sides, is decorated with oblique impressions of a comb stamp, rarely smooth or other types of serrated. In the rim area there is a belt of rounded pits. The main part of the ornamental composition is represented by lines of a receding scapula or rows of impressions of comb, larval and other types of serrated stamp (rarely smooth). Posolskaya type pottery was found at Nyasha and one fragment at Bazaikha. Vessels have a closed shape with weak profiling. The ornament is localized in the upper part of the vessel and, in general, demonstrates the stability of the compositions: in all cases, horizontal motifs predominate. The rims are decorated on the outside with imprints of a comb stamp set at an angle and have a belt of round holes. Below the composition continues with horizontal drawn lines, or a receding shoulder blade with a narrow-rounded working edge. Overall, the collection of Neolithic ceramics of both types finds broad analogies in the materials of Baikal-Yenisei Siberia. The lower time limits for both types of ceramics in the region are determined by the dates from the Elenev Cave site – 6900±115 BP (SOAN-3998) for the Posolskaya type and 6475±190 BP (SOAN-2906) for the Ust-Belaya type. The upper limit is determined in the same way according to the date from Nyasha 4080±60 BP. However, for the Southern Angara and Baikal regions, dates were obtained in a narrower chronorange from 5852±34 (ОхА-22373) to 5585±20 BP (UCIAMS-207539).

Усть-бельская керамика с эпонимного местонахождения из фондов Иркутского областного краеведческого музея им. Н. Н. Муравьева-Амурского

This article presents Ust-Belaya ceramics of the Ust-Belaya site from the funds of the Muravyov-Amursky Irkutsk Regional Museum of Local History. The multilayered site Ust-Belaya is located 110 km northwest of Irkutsk at the Belaya River mouth (left tributary of the Angara). The considered Ust-Belaya ceramics belongs to the finds from the excavations of 1958–1964. The collection includes 1331 fragments from at least 60 pots. The vessels have a simple closed, rarely open shape and a rounded bottom. The ornament could be located both the upper part of the vessel and cover it entirely. Vessels ornamented with horizontal straight lines predominate. In three cases they are complemented by zigzag lines. The rim on the outer side or on both sides is decorated with oblique impressions of a comb stamp, rarely smooth or other varieties of serrated tools. Almost all vessels in the rim area have a line of rounded pits. The main part of the ornamental composition is represented by lines of a receding scapula or rows of impressions of comb, larval and other types of toothed stamp (rarely smooth), which are set close, separately or using the technique of retreat. Signs of making, recorded on ceramics during the study, allow us to identify several features in the production of Ust-Belaya type ceramics. The vessels were formed by the method of zonal patchwork modeling, partially or almost completely on a base form, which could be another vessel. In the production of vessels, they were knocked out with a smooth mallet, achieving dense and thin walls. Upon completion of the modeling, a rim was formed using an additional structural element such as a conditional tape or funiculus. Then the vessel was ornamented, and the walls were smoothed or rubbed from the inside. Since the finds of 1958–1964 deposited in a mixed compression layer, which complicates dating. In 2017–2018 at the Ust-Belaya site, located on the middle floodplain, Ust-Belaya pottery was recorded in a clear stratigraphic position. Based on bones from the layer, dates were obtained with a range of 6730–6306 cal BP. Also, according to one Ust-Belaya vessel from other excavations of Ust-Belaya in 1957, a date was obtained from carbonized organic residues (foodcrusts) from the inner surface with a value of 6977–6800 cal BP. By analogy with these assemblages, the age of the collection of Ust- Belaya ceramics presented by us is tentatively determined in the range of 6977–6306 cal BP.

Endoparacite investigation in some fish species with high economic value obtained from Çanakkale

The study is an endoparasitic examination of chub mackerel (Scomber japonicus Houttuyn 1782), bogue (Boops boops Linnaeus 1758), horse mackerel (Trachurus trachurus Linnaeus 1758), sardine (Sardina pilchardus Walbaum 1792), and anchovy (Engraulis encrasicolus Linnaeus 1758) fish taken from Çanakkale fish state as an annual sampling between 01 September 2019- 01 September 2020. One thousand three hundred thirty-seven fishes were sampled. The external morphological examination of the fish brought to the laboratory was made, then the conditions of their visceral organs and their visceral structures were examined by dissection method. Nematodes collected alive from many parts of the body were kept in absolute (99.9%) ethanol. Parasites in ethanol were kept in glycerin for a few days before being examined under the microscope. &#x0D; Nematodes were first examined morphologically on a stereomicroscope and then under a light microscope for easy species identification. Classical detection methods have been used for species determination. As a result, among the individuals belonging to the Anisakidae family, Anisakis spp. L3 larval stage type 1 and type 2, Anisakis physeteris larval stage, Contracaecum larval stage, Hysterothylacium aduncum L3 larval stage were found. The density, abundance, and prevalence rates of the parasites in the infected fish are determined as a percentage.

Predatory and competitive interaction in Anopheles gambiae sensu lato larval breeding habitats in selected villages of central Uganda

BackgroundMalaria is often persistent in communities surrounded by mosquito breeding habitats. Anopheles gambiae sensu lato exploit a variety of aquatic habitats, but the biotic determinants of its preferences are poorly understood. This study aimed to identify and quantify macroinvertebrates in different habitat types with determined water physico-chemical parameters to establish those preferred by An. gambiae s.l. larvae as well as their predators and competitors.MethodsA field survey was conducted in Kibuye and Kayonjo villages located in the vicinity of the River Sezibwa, north-eastern Uganda to identify Anopheline larval habitats shared by aquatic insects. Habitats were geo-recorded and as streams, ponds, temporary pools and roadside ditches. From October to December 2017, random microhabitats/quadrats were selected from each habitat type, their water physico-chemical parameters (electrical conductivity, total dissolved solids, temperature and pH) were measured, and they were sampled for macroinvertebrates using standard dippers. All collected arthropod macroinvertebrates were then morphologically identified to family level and enumerated.ResultsPrincipal component analysis showed that the four larval habitat types were characterized by distinct physico-chemical parameter profiles. Ponds and streams had the highest number and diversity of macroinvertebrate insect taxa and sustained few An. gambiae s.l. larvae. Anopheles gambiae s.l. were more common in roadside ditches and particularly abundant in temporary pools which it commonly shared with Dytiscidae (predaceous diving beetles) and Culex spp. Cluster correlation analysis conducted on the abundance of these taxa within quadrats suggested that An. gambiae s.l. and Dytiscidae have the most similar patterns of microhabitat use, followed by Cybaeidae (water spiders). Whilst Culex spp. co-occurred with An. gambiae s.l. in some habitats, there was only partial niche overlap and no clear evidence of competition between the two mosquito taxa.ConclusionsPonds and streams are habitats that host the largest diversity and abundance of aquatic insect taxa. Anopheles gambiae s.l. larvae distinctively preferred temporary pools and roadside ditches, where they were exposed to few predators and no apparent competition by Culex spp. Further studies should aim to test the impact of Dytiscidae and Cybaeidae on An. gambiae s.l. dynamics experimentally.Graphical

Size variation in wild Bactrocera tryoni (Diptera: Tephritidae): only a small amount is related to the host fruit

AbstractBody size is an indicator of fitness in fruit flies (Diptera: Tephritidae), with larger males and females having increased mating success and egg production, respectively. Based on laboratory studies, the larval diet and its nutritional composition are considered the most important factors influencing juvenile growth and subsequent adult body size. However, a very limited literature is less clear on the importance of larval diet as an adult size modifier of wild fruit flies. Bactrocera tryoni (Froggatt) is a polyphagous species with larvae feeding within the fruit of over 200 plant species. To test the impact of larval host on adult size in wild individuals of this species, we collected naturally infested fruit from the field and then reared out adults in the laboratory. The wing length and dry body weight of emergent flies were measured. Linear mixed models were used to analyse the difference in size depending on fruit type, larval density, sex and their interactions. Separate measurements of body size, wing length and dry body weight were significantly influenced by the larval host fruit collected from the field. However, only 7% and 24% of the variation of the wing discal–medial cell length and dry body weight, respectively, could be explained by larval host fruit type with high individual body size variation both within and between host fruit types. Fruit protein content was positively correlated, and water content negatively correlated, to wing discal–medial cell length. Unexpectedly, the parameters of wing length and dry body weight were only weakly correlated with each other. The results support the large body of laboratory‐based fruit fly diet work, which identifies protein as a key component of the larval diet, but do not support a general assumption that larval host is the key driver of adult body size variation in wild frugivorous tephritids. Rather, and in agreement with a small number of laboratory‐based trials, the importance of larval diet to adult fitness appears to become less important as the larval feeding environment becomes more complex.

Light-trapped caddisflies to decipher the role of species traits and habitats in Hg accumulation and transfer

We present a novel meta-community approach to explore the influence of species traits, such as adult body size, larval feeding type and microhabitat, as well as larval macrohabitat (main river channel vs. floodplain water bodies) on the concentration of total Hg accumulated ([THg]) in assemblages of adult caddisflies. We analyzed [THg] in 157 light-trapped adult caddisflies in a floodplain sector of the French upper Rhône River and used a linear mixed effect model to decipher the role of species traits and habitats in Hg accumulation. Variation of [THg] between species was best explained by the larval feeding type, whereas the contributions of adult size and larval micro and macro-habitat were minor. Results showed that [THg] in species associated with floodplain macrohabitats in the larval stage was lower than in those associated with the main river channel. This difference could depend on complexation of Hg by DOM (in the floodplain) and MES (in the main channel). This research provides a first evidence of the potential of an entire caddisfly assemblage for the assessment of contamination in large alluvial rivers. The implications of the results are discussed in view of the possible role of caddisflies as vectors of Hg to riparian predators.

Signals of Positive Selection in Sea Slug Transcriptomes.

AbstractUnderstanding how species may respond to climate change is of paramount importance. Species that occupy highly heterogenous environments, such as intertidal zone estuarine habitats, provide an ideal test case for examining phenotypic and genomic adaptations to different environmental conditions, which may influence their response to rapidly shifting climatic conditions. The California coast is projected to experience changes in both temperature and salinity, which currently vary seasonally and latitudinally. Using comparative transcriptomics, I documented patterns of positive selection between the northern-dwelling planktotrophic sacoglossan sea slug Alderia modesta, which is remarkably tolerant of low temperatures and low salinities, and its southern congener Alderia willowi, which exhibits a striking flexibility for larval type in response to seasonally shifting changes in temperature and salinity. Out of over 4000 1-to-1 orthologous genes, I found a signal of positive selection between A. willowi and A. modesta for genes involved in cell membrane and cell transport, particularly ion homeostasis (aquaporin), cell-cell signal transduction, and phosphorylation (reduced nicotinamide adenine dinucleotide [NADH] dehydrogenase). Positive selection for ion homeostasis in A. modesta has implications for its ability to tolerate the lower salinity of its northern range, and in A. willowi substitutions in NADH may assist in the high temperature tolerance of its southern California habitats. Identifying these candidate genes enables future studies of their functionalization as we seek to understand the relationship between phenotype and genotype in species whose phenotypes are influenced by environmental conditions.

A novel larval diet interacts with nutritional stress to modify juvenile behaviors and glucocorticoid responses.

Developmental plasticity can allow the exploitation of alternative diets. While such flexibility during early life is often adaptive, it can leave a legacy in later life that alters the overall health and fitness of an individual. Species of the spadefoot toad genus Spea are uniquely poised to address such carryover effects because their larvae can consume drastically different diets: their ancestral diet of detritus or a derived shrimp diet. Here, we use Spea bombifrons to assess the effects of developmental plasticity in response to larval diet type and nutritional stress on juvenile behaviors and stress axis reactivity. We find that, in an open‐field assay, juveniles fed shrimp as larvae have longer latencies to move, avoid prey items more often, and have poorer prey‐capture abilities. While juveniles fed shrimp as larvae are more exploratory, this effect disappears if they also experienced a temporary nutritional stressor during early life. The larval shrimp diet additionally impairs juvenile jumping performance. Finally, larvae that were fed shrimp under normal nutritional conditions produce juveniles with higher overall glucocorticoid levels, and larvae that were fed shrimp and experienced a temporary nutritional stressor produce juveniles with higher stress‐induced glucocorticoid levels. Thus, while it has been demonstrated that consuming the novel, alternative diet can be adaptive for larvae in nature, doing so has marked effects on juvenile phenotypes that may recalibrate an individual's overall fitness. Given that organisms often utilize diverse diets in nature, our study underscores the importance of considering how diet type interacts with early‐life nutritional adversity to influence subsequent life stages.

RNA-Seq reveals divergent gene expression between larvae with contrasting trophic modes in the poecilogonous polychaete Boccardia wellingtonensis

The polychaete Boccardia wellingtonensis is a poecilogonous species that produces different larval types. Females may lay Type I capsules, in which only planktotrophic larvae are present, or Type III capsules that contain planktotrophic and adelphophagic larvae as well as nurse eggs. While planktotrophic larvae do not feed during encapsulation, adelphophagic larvae develop by feeding on nurse eggs and on other larvae inside the capsules and hatch at the juvenile stage. Previous works have not found differences in the morphology between the two larval types; thus, the factors explaining contrasting feeding abilities in larvae of this species are still unknown. In this paper, we use a transcriptomic approach to study the cellular and genetic mechanisms underlying the different larval trophic modes of B. wellingtonensis. By using approximately 624 million high-quality reads, we assemble the de novo transcriptome with 133,314 contigs, coding 32,390 putative proteins. We identify 5221 genes that are up-regulated in larval stages compared to their expression in adult individuals. The genetic expression profile differed between larval trophic modes, with genes involved in lipid metabolism and chaetogenesis over expressed in planktotrophic larvae. In contrast, up-regulated genes in adelphophagic larvae were associated with DNA replication and mRNA synthesis.

Functional groups of hoverflies inSoutheast Europeacross different vegetation types

AbstractTo better understand the relationship between biodiversity and ecosystem functioning, it is increasingly accepted that the focus of study needs to shift from taxonomic identity to the diversity of functional traits displayed by species within a community. Such an approach allows species to be grouped according to particular functional characteristics. Increasingly viewed as an extremely important group of model organisms, hoverflies have been the focus of a variety of ecological studies. Based on data regarding selected functional traits of hoverflies registered in Southeast Europe, the main aims of our study were to define hoverfly functional groups according to the similarity of these traits, as well as to compare the representation of delineated hoverfly functional groups among these vegetation types. We used fuzzy clustering to classify 568 SE European hoverfly species into five functional groups. The principle trait separating these functional groups was larval feeding type, followed by size of species range, flight ability, number of generations, inundation tolerance, and tolerance to human impact. For 9 of 11 vegetation types, the dominant functional group was characterized by species with good flight ability, having high human impact tolerance and more annual generations. The remaining two vegetation types, South‐west Balkan sub‐Mediterranean mixed oak forests and Mediterranean mixed forests, showed disparate dominance patterns, indicating that richness of functional groups is dependent on vegetation. Further investigation of whether and how established conservation measures enable recovery of the functional richness affected by habitat disturbance would help elucidate the importance of functional diversity in preserving biodiversity.

Larval habitat diversity and Anopheles mosquito species distribution in different ecological zones in Ghana

BackgroundUnderstanding the ecology of larval malaria and lymphatic filariasis mosquitoes in a changing environment is important in developing effective control tools or programmes. This study characterized the breeding habitats of Anopheles mosquitoes in rural communities in different ecological zones in Ghana during the dry and rainy seasons.MethodsThe spatio-temporal distribution, species composition, and abundance of larval Anopheles mosquitoes in breeding habitats were studied in five locations in three ecological zones of Ghana. These were Anyakpor (coastal savannah area), Duase (forest area), and Libga, Pagaza, and Kpalsogu (Sahel savannah area). Larvae were collected using standard dippers and were raised in the insectary for identification.ResultsOut of a total of 7984 mosquito larvae collected, 2152 (27.26%) were anophelines and were more abundant in the rainy season (70.82%) than in the dry season (29.18%). The anophelines comprised 2128 (98.88%) An. gambiae s.l., 16 (0.74%) An. rufipes, and 8 (0.37%) An. pharoensis. In the coastal savannah and forest zones, dug-out wells were the most productive habitat during the dry (1.59 larvae/dip and 1.47 larvae/dip) and rainy seasons (11.28 larvae/dip and 2.05 larvae/dip). Swamps and furrows were the most productive habitats in the Sahel savannah zone during the dry (0.25 larvae/dip) and rainy (2.14 larvae/dip) seasons, respectively. Anopheles coluzzii was the most abundant sibling species in all the ecological zones. Anopheles melas and An. arabiensis were encountered only in the coastal savannah and the Sahel savannah areas, respectively. Larval habitat types influenced the presence of larvae as well as larval density (p < 0.001). The land-use type affected the presence of Anopheles larvae (p = 0.001), while vegetation cover influenced larval density (p < 0.05).ConclusionThe most productive habitats were dug-out wells in the coastal savannah and forest zones, and furrows from irrigated canals in the Sahel savannah zone. Anopheles coluzzii was the predominant vector species in all the ecological zones. The abundance of Anopheles breeding habitats and larvae were influenced by anthropogenic activities. Encouraging people whose activities create the larval habitats to become involved in larval source management such as habitat manipulation to stop mosquito breeding will be important for malaria and lymphatic filariasis control.

An investigation of zoonotic nematodes of loach Paramisgurnus dabryanus Dabry de Thiersant, under high-density pond farming pattern in China

Loach Paramisgurnus dabryanus Dabry de Thiersant is extensively cultured in high-density pond farming pattern in China. To detect the occurrence of zoonotic nematode and confirm the safety of this commercial fish under the farming pattern, a total of 934 farmed as well as wild loach collected from five provinces in China, were subjected to parasitological examination. Results showed the absence of zoonotic nematodes in all farmed loach, only the wild surveyed in Anhui was infected with Contracaecum at the third developmental stage, with prevalence and mean abundance of 66.6% and 4.4, respectively. Morphological and molecular results indicated that the larval type found in the present study may be an unreported species, while this cannot be ascertained completely, due to the paucity of specimens at the adult stage. Additionally, the larvae at the third stage found in the wild loach suggested that they are still in infective stages. It is therefore highly possible for them to transfer to consumers when fish infected with larval was ingested undercooked or raw. To some extent, the high-density pond farming pattern of loach under manual intervention in China can reduce the risk of these aquatic products to consumers.

Congruence between molecular and morphological systematics of Alpine non‐biting midges (Chironomidae, Diamesinae)

AbstractIn mountain regions, climate change is resulting in glacial retreat, causing biodiversity loss in glacial‐fed streams (kryal habitat). Diamesa species (Diptera Chironomidae), the main colonizers of the kryal in the Alps, are the aquatic insects more threatened by extinction. In recent years, DNA barcoding was successfully adopted to delimit species of chironomids and provided species identification. We highlighted that for the Diamesa genus, inconsistencies remain between identification on a morphological and molecular basis, mainly within cinerella and zernyi groups, raising doubts about the validity of head colour as a good diagnostic taxonomic character. Molecular phylogeny reconstruction based on mitochondrial (cytochrome oxidase subunits I and II) and one nuclear (ribosomal 18S rRNA) markers revealed that D. bohemani and D. zernyi on one hand, and D. cinerella and D. tonsa on the other hand, represent populations of the same species. Divergence times suggested that the radiation of these alpine species seems to have been driven by the climatic events with the alternation of glacial periods that happened in the Pliocene and Pleistocene. The initial separation of the oriental species D. steinboecki seems to be due to the tectonic movements of the Periadriatic fault system that probably favoured the emergence of lakes and streams, successively colonized by D. steinboecki. This study raises important concerns, from the validity of diagnostic characters used today to identify larval types up to the uncertainty about how many species of Diamesa inhabit the European Alps and what their fate will be within the scenario of climate change.