Multiple and frequent trypanosomatid co-infections of insects: the Cuban case study.

Trypanosomatids are obligate parasites of animals, predominantly insects and vertebrates, and flowering plants. Monoxenous species, representing the vast majority of trypanosomatid diversity, develop in a single host, whereas dixenous species cycle between two hosts, of which primarily insect serves as a vector. To explore in-depth the diversity of insect trypanosomatids including their co-infections, sequence profiling of their 18S rRNA gene was used for true bugs (Hemiptera; 18% infection rate) and flies (Diptera; 10%) in Cuba. Out of 48 species (molecular operational taxonomic units) belonging to the genera Vickermania (16 spp.), Blastocrithidia (7), Obscuromonas (4), Phytomonas (5), Leptomonas/Crithidia (5), Herpetomonas (5), Wallacemonas (2), Kentomonas (1), Angomonas (1) and two unnamed genera (1 + 1), 38 species have been encountered for the first time. The detected Wallacemonas and Angomonas species constitute the most basal lineages of their respective genera, while Vickermania emerged as the most diverse group. The finding of Leptomonas seymouri, which is known to rarely infect humans, confirms that Dysdercus bugs are its natural hosts. A clear association of Phytomonas with the heteropteran family Pentatomidae hints at its narrow host association with the insect rather than plant hosts. With a focus on multiple infections of a single fly host, using deep Nanopore sequencing of 18S rRNA, we have identified co-infections with up to 8 trypanosomatid species. The fly midgut was usually occupied by several Vickermania species, while Herpetomonas and/or Kentomonas species prevailed in the hindgut. Metabarcoding was instrumental for analysing extensive co-infections and also allowed the identification of trypanosomatid lineages and genera.

Dominance of non-wetland-dependent pollinators in a plant community in a small natural wetland in Shimane, Japan.

Many wetland plants rely on insects for pollination. However, studies examining pollinator communities in wetlands remain limited. Some studies conducted in large wetlands (> 10 ha) have suggested that wetland-dependent flies, which spend their larval stage in aquatic and semi-aquatic habitats, dominate as pollinators. However, smaller wetlands surrounded by secondary forests are more prevalent in Japan, in which pollinators from the surrounding environment might be important. Additionally, information regarding floral traits that attract specific pollinator groups in wetland communities is scarce. Therefore, this study aimed to understand the characteristics of insect pollinators in a small natural wetland (2.5 ha) in Japan. We examined the major pollinator groups visiting 34 plant species and explored the relationship between the flower visitation frequency of each pollinator group and floral traits. Overall, flies were the most dominant pollinators (42%), followed by bees and wasps (33%). Cluster analysis indicated that fly-dominated plants were the most abundant among 14 of the 34 target plant species. However, 85% of the hoverflies, the most abundant flies, and 82% of the bees were non-wetland-dependent species, suggesting that these terrestrial species likely originated from the surrounding environment. Therefore, pollinators from the surrounding environment would be important in small natural wetlands. Flies tend to visit open and white/yellow flowers, whereas bees tended to visit tube-shaped flowers, as in forest and grassland ecosystems. The dominance of flies in small wetlands would be due to the dominance of flowers preferred by flies (e.g., yellow/white flowers) rather than because of their larval habitats.

Aedes aegypti exhibits a distinctive mode of late ovarian development.

BACKGROUND: Insects live in almost every habitat on earth. To adapt to their diverse environments, insects have developed a myriad of different strategies for reproduction reflected in diverse anatomical and behavioral features that the reproductive systems of females exhibit. Yet, ovarian development remains largely uncharacterized in most species except Drosophila melanogaster (D. melanogaster), a high Diptera model. In this study, we investigated the detailed developmental process of the ovary in Aedes aegypti (Ae. aegypti), a major vector of various disease-causing pathogens that inhabits tropical and subtropical regions. RESULTS: Compared with Drosophila melanogaster, a model of higher Diptera, the processes of pole cell formation and gonad establishment during embryonic stage are highly conserved in Ae. aegypti. However, Ae. aegypti utilizes a distinct strategy to form functional ovaries during larval/pupal development. First, during larval stage, Ae. aegypti primordial germ cells (PGCs) undergo a cyst-like proliferation with synchronized divisions and incomplete cytokinesis, leading to the formation of one tightly packed "PGC mass" containing several interconnected cysts, different from D. melanogaster PGCs that divide individually. This cyst-like proliferation is regulated by the target of rapamycin (TOR) pathway upon nutritional status. Second, ecdysone-triggered ovariole formation during metamorphosis exhibits distinct events, including "PGC mass" breakdown, terminal filament cell degeneration, and pre-ovariole migration. These unique developmental features might explain the structural and behavioral differences between Aedes and Drosophila ovaries. Importantly, both cyst-like proliferation and distinct ovariole formation are also observed in Culex quinquefasciatus and Anopheles sinensis, suggesting a conserved mode of ovarian development among mosquito species. In comparison with Drosophila, the ovarian development in Aedes and other mosquitoes might represent a primitive mode in the lower Diptera. CONCLUSIONS: Our study reveals a new mode of ovarian development in mosquitoes, providing insights into a better understanding of the reproductive system and evolutionary relationship among insects.

Black blow fly (Diptera: Calliphoridae) bacterial symbionts inform oviposition site selection by stable flies (Diptera: Muscidae).

Larval habitats of blood-feeding stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), overlap with foraging sites of black blow flies, Phormia regina (Meigen) (Diptera: Calliphoridae). We tested the hypothesis that bacteria in blow fly excreta inform oviposition decisions by female stable flies. In laboratory 2-choice bioassays, we offered gravid female stable flies fabric-covered agar plates as oviposition sites that were kept sterile or inoculated with either a blend of 7 bacterial strains isolated from blow fly excreta (7-isolate-blend) or individual bacterial isolates from that blend. The 7-isolate-blend deterred oviposition by female stable flies, as did either of 2 strains of Morganella morganii subsp. sibonii. Conversely, Exiguobacterium sp. and Serratia marcescens each prompted oviposition by flies. The flies' oviposition decisions appear to be guided by bacteria-derived semiochemicals as the bacteria could not be physically accessed. Oviposition deterrence caused by semiochemicals of the 7-isolate-blend may help stable flies avoid competition with blow flies. The semiochemicals of bioactive bacterial strains could be developed as trap lures to attract and capture flies and deter their oviposition in select larval habitats.

Phylotranscriptomics Reveals Discordance in the Phylogeny of Hawaiian Drosophila and Scaptomyza (Diptera: Drosophilidae).

Island radiations present natural laboratories for studying the evolutionary process. The Hawaiian Drosophilidae are one such radiation, with nearly 600 described species and substantial morphological and ecological diversification. These species are largely divided into a few major clades, but the relationship between clades remains uncertain. Here, we present new assembled transcriptomes from 12 species across these clades, and use these transcriptomes to resolve the base of the evolutionary radiation. We recover a new hypothesis for the relationship between clades, and demonstrate its support over previously published hypotheses. We then use the evolutionary radiation to explore dynamics of concordance in phylogenetic support, by analyzing the gene and site concordance factors for every possible topological combination of major groups. We show that high bootstrap values mask low evolutionary concordance, and we demonstrate that the most likely topology is distinct from the topology with the highest support across gene trees and from the topology with highest support across sites. We then combine all previously published genetic data for the group to estimate a time-calibrated tree for over 300 species of drosophilids. Finally, we digitize dozens of published Hawaiian Drosophilidae descriptions, and use this to pinpoint probable evolutionary shifts in reproductive ecology as well as body, wing, and egg size. We show that by examining the entire landscape of tree and trait space, we can gain a more complete understanding of how evolutionary dynamics play out across an island radiation.

Stable pollination service in a generalist high Arctic community despite the warming climate.

Insects provide key pollination services in most terrestrial biomes, but this service depends on a multistep interaction between insect and plant. An insect needs to visit a flower, receive pollen from the anthers, move to another conspecific flower, and finally deposit the pollen on a receptive stigma. Each of these steps may be affected by climate change, and focusing on only one of them (e.g., flower visitation) may miss important signals of change in service provision. In this study, we combine data on visitation, pollen transport, and single-visit pollen deposition to estimate functional outcomes in the high Arctic plant-pollinator network of Zackenberg, Northeast Greenland, a model system for global warming-associated impacts in pollination services. Over two decades of rapid climate warming, we sampled the network repeatedly: in 1996, 1997, 2010, 2011, and 2016. Although the flowering plant and insect communities and their interactions varied substantially between years, as expected based on highly variable Arctic weather, there was no detectable directional change in either the structure of flower-visitor networks or estimated pollen deposition. For flower-visitor networks compiled over a single week, species phenologies caused major within-year variation in network structure despite consistency across years. Weekly networks for the middle of the flowering season emerged as especially important because most pollination service can be expected to be provided by these large, highly nested networks. Our findings suggest that pollination ecosystem service in the high Arctic is remarkably resilient. This resilience may reflect the plasticity of Arctic biota as an adaptation to extreme and unpredictable weather. However, most pollination service was contributed by relatively few fly taxa (Diptera: Spilogona sanctipauli and Drymeia segnis [Muscidae] and species of Rhamphomyia [Empididae]). If these key pollinators are negatively affected by climate change, network structure and the pollination service that depends on it would be seriously compromised.

Field-Reassortment of Bluetongue Virus Illustrates Plasticity of Virus Associated Phenotypic Traits in the Arthropod Vector and Mammalian Host In Vivo.

Segmented RNA viruses are a taxonomically diverse group that can infect plant, wildlife, livestock and human hosts. A shared feature of these viruses is the ability to exchange genome segments during coinfection of a host by a process termed "reassortment." Reassortment enables rapid evolutionary change, but where transmission involves a biological arthropod vector, this change is constrained by the selection pressures imposed by the requirement for replication in two evolutionarily distant hosts. In this study, we use an in vivo, host-arbovirus-vector model to investigate the impact of reassortment on two phenotypic traits, virus infection rate in the vector and virulence in the host. Bluetongue virus (BTV) (Reoviridae) is the causative agent of bluetongue (BT), an economically important disease of domestic and wild ruminants and deer. The genome of BTV comprises 10 linear segments of dsRNA, and the virus is transmitted between ruminants by Culicoides biting midges (Diptera: Ceratopogonidae). Five strains of BTV representing three serotypes (BTV-1, BTV-4, and BTV-8) were isolated from naturally infected ruminants in Europe and ancestral/reassortant lineage status assigned through full genome sequencing. Each strain was then assessed in parallel for the ability to replicate in vector Culicoides and to cause BT in sheep. Our results demonstrate that two reassortment strains, which themselves became established in the field, had obtained high replication ability in C. sonorensis from one of the ancestral virus strains, which allowed inferences of the genome segments conferring this phenotypic trait. IMPORTANCE Reassortment between virus strains can lead to major shifts in the transmission parameters and virulence of segmented RNA viruses, with consequences for spread, persistence, and impact. The ability of these pathogens to adapt rapidly to their environment through this mechanism presents a major challenge in defining the conditions under which emergence can occur. Utilizing a representative mammalian host-insect vector infection and transmission model, we provide direct evidence of this phenomenon in closely related ancestral and reassortant strains of BTV. Our results demonstrate that efficient infection of Culicoides observed for one of three ancestral BTV strains was also evident in two reassortant strains that had subsequently emerged in the same ecosystem.

Close to complete conservation of the brachyceran opsin repertoire in the stalk-eyed fly Teleopsis dalmanni.

Due to the unique morphology of their adult visual system, stalk-eyed flies represent an important model of exaggerated trait evolution through sexual selection. Early physiological measurements indicated wavelength sensitivity peaks in the ultraviolet (360 nm), blue (450), blue-green (490 nm), and red (>550 nm) ranges in the compound eye retina of the stalk-eyed fly Teleopsis dalmanni, consistent with the trichromatic color and broad range motion detection vision system of brachyceran Diptera. A previous study of dipteran opsin gene diversification, however, detected only homologs of members of the long wavelength range sensitive opsin subfamilies Rh2 and Rh6 in T. dalmanni. Here, I report findings from analyzing the most recent T. dalmanni genome assembly, which revealed the conservation of most brachyceran opsin homologs except for the UV wavelength range-sensitive homolog Rh4. These results and other examples highlight the caution that needs to be applied to gene loss conclusions.

First phylogenetic analysis of the Nearctic madicolous midges of the genus Androprosopa Mik (Diptera: Thaumaleidae).

Molecular phylogenetic analyses were conducted to infer relationships between the eastern and western Nearctic Androprosopa Mik and amongst the considerably more diverse western Nearctic species. Fresh, molecular-grade material was obtained for all Nearctic Androprosopa species except two Mexican species, An. sonorensis (Arnaud & Boussy) and An. zempoala Sinclair & Huerta, that eluded capture. Molecular sequences from two nuclear protein-coding genes, big zinc finger (BZF) and molybdenum cofactor sulfurase (MCS), were sampled from representatives of several outgroup and ingroup taxa and analyzed phylogenetically using maximum likelihood criteria to confirm identifications of females and immatures using a barcoding approach, test species boundaries among morphologically similar species, and infer relationships among more morphologically disparate groups. Resulting phylogenies suggest the following with significant node (bootstrap) support: (1) the eastern Nearctic Androprosopa species form the sister group to the lineage comprised of all sampled Palearctic thaumaleids, i.e., An. larvata (Mik), An. striata (Okada), and Thaumalea testacea Ruthe; (2) the aforementioned lineage is the sister group to the clade comprised of western Nearctic Androprosopa species; (3) the western Nearctic Androprosopa species form three multispecies lineages, two of which can be further divided into three or more well founded species groups. Our results suggest that Androprosopa as currently defined is paraphyletic. Additionally, we propose several new species groups within the western Nearctic Androprosopa based on molecular and morphological data.

The phylogeny and divergence times of leaf-mining flies (Diptera: Agromyzidae) from anchored phylogenomics.

Leaf-mining flies (Diptera: Agromyzidae) are a diverse clade of phytophagous Diptera known largely for their economic impact as leaf- or stem-miners on vegetable and ornamental plants. Higher-level phylogenetic relationships of Agromyzidae have remained uncertain because of challenges in sampling of both taxa and characters for morphology and PCR-based Sanger-era molecular systematics. Here, we used hundreds of orthologous single-copy nuclear loci obtained from anchored hybrid enrichment (AHE) to reconstruct phylogenetic relationships among the major lineages of leaf-mining flies. The resulting phylogenetic trees are highly congruent and well-supported, except for a few deep nodes, when using different molecular data types and phylogenetic methods. Based on divergence time dating using a relaxed clock model-based analysis, leaf-mining flies are shown to have diversified in multiple lineages since the early Paleocene, approximately 65 million years ago. Our study not only reveals a revised classification system of leaf-mining flies, but also provides a new phylogenetic framework to understand their macroevolution.

Crop-pollinating Diptera have diverse diets and habitat needs in both larval and adult stages.

Insects are important pollinators of global food crops and wild plants. The adult and larval diet and habitat needs are well known for many bee taxa, but poorly understood for other pollinating taxa. Non-bee pollinators often feed on different substrates in their larval and adult life stages, and this diet and habitat diversity has important implications for their conservation and management. We reviewed the global literature on crop pollinating Diptera (the true flies) to identify both larval and adult fly diet and habitat needs. We then assembled the published larval and adult diets and habitat needs of beneficial fly pollinators found globally into a freely accessible database. Of the 405 fly species known to visit global food crops, we found relevant published evidence regarding larval and adult diet and habitat information for 254 species, which inhabited all eight global biogeographic regions. We found the larvae of these species lived in 35 different natural habitats and belong to 10 different feeding guilds. Additionally, differences between adult Diptera sexes also impacted diet needs; females from 14 species across five families fed on protein sources other than pollen to start the reproductive process of oogenesis (egg development) while males of the same species fed exclusively on pollen and nectar. While all adult species fed at least partially on floral nectar and/or pollen, only five species were recorded feeding on pollen and no fly larvae fed on nectar. Of the 242 species of larvae with established diet information, 33% were predators (n = 79) and 30% were detritivores (n = 73). Detritivores were the most generalist taxa and utilized 17 different habitats and 12 different feeding substrates. Of all fly taxa, only 2% belonged to the same feeding guild in both active life stages. Our results show that many floral management schemes may be insufficient to support pollinating Diptera. Pollinator conservation strategies in agroecosystems should consider other non-floral resources, such as wet organic materials and dung, as habitats for beneficial fly larvae.

The first complete mitochondrial genome sequences for Ulidiidae and phylogenetic analysis of Diptera.

BACKGROUND: Tetanops sintenisi is a pest that mainly damages the root of quinoa (Chenopodium quinoa) and it is first discovered in China in 2018. METHODS AND RESULTS: Here, the complete mitochondrial genome (mitogenome) of T. sintenisi was sequenced and compared with the mitogenomes of other Diptera species. The results revealed that the mitogenome of T. sintenisi is 15,763 bp in length (GenBank accession number: MT795181) and is comprised of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA genes, and a non-coding A + T-rich region (959 bp). The highly conserved gene arrangement of the mitogenome of T. sintenisi was identical to that of other Diptera insects. Twelve PCGs contained the typical insect start codon ATN, while cox1 had CGA as the start codon. The genes cox2, nad4, and nad1 contained an incomplete termination codon T; nad3, nad5, and cob contained the complete termination codon TAG; and the remaining seven PCGs contained the termination codon TAA. All tRNA genes were predicted to fold into the typical cloverleaf secondary structure. Phylogenetic analysis of 48 species based on the mitogenome sequence revealed that T. sintenisi clustered with the Tephritidae family, indicating that T. sintenisi and Tephritidae have a close phylogenetic relationship. CONCLUSIONS: The phylogenetic relationship of T. sintenisi based on the mitogenome is consistent with the traditional morphological taxonomy, according to which T. sintenisi belongs to the family Otitidae, which is closely related to the family Muscidae.

The blowfly Chrysomya latifrons inhabits fragmented rainforests, but shows no population structure.

Climate change and deforestation are causing rainforests to become increasingly fragmented, placing them at heightened risk of biodiversity loss. Invertebrates constitute the greatest proportion of this biodiversity, yet we lack basic knowledge of their population structure and ecology. There is a compelling need to develop our understanding of the population dynamics of a wide range of rainforest invertebrates so that we can begin to understand how rainforest fragments are connected, and how they will cope with future habitat fragmentation and climate change. Blowflies are an ideal candidate for such research because they are widespread, abundant, and can be easily collected within rainforests. We genotyped 188 blowflies (Chrysomya latifrons) from 15 isolated rainforests and found high levels of gene flow, a lack of genetic structure between rainforests, and low genetic diversity - suggesting the presence of a single large genetically depauperate population. This highlights that: (1) the blowfly Ch. latifrons inhabits a ~ 1000 km stretch of Australian rainforests, where it plays an important role as a nutrient recycler; (2) strongly dispersing flies can migrate between and connect isolated rainforests, likely carrying pollen, parasites, phoronts, and pathogens along with them; and (3) widely dispersing and abundant insects can nevertheless be genetically depauperate. There is an urgent need to better understand the relationships between habitat fragmentation, genetic diversity, and adaptive potential-especially for poorly dispersing rainforest-restricted insects, as many of these may be particularly fragmented and at highest risk of local extinction.

Bat-parasite interaction networks in urban green areas in northeastern Brazil.

Interaction networks can provide detailed information regarding ecological systems, helping us understand how communities are organized and species are connected. The goals of this study were to identify the pattern of interaction between bats and ectoparasites in urban green areas of Grande Aracaju, Sergipe, and calculate connectance, specialization, nesting, modularity and centrality metrics. Bats were captured using 10 mist nets inside and on the edges of the fragments, and the collected ectoparasites were stored in 70% alcohol. All analyses were performed using R software. The interaction network consisted of 10 species of bats and 13 ectoparasites. Connectivity was considered low (0.12). The specialization indices for ectoparasites ranged from 0.50 to 1.00, and the value obtained for the network was 0.96, which is high. The observed nesting metric was low (wNODF = 1.47), whereas the modularity was high (wQ = 0.74), indicating that the studied network had a modular topology. All centrality metrics had low values. The observed modularity may have been caused by the evolutionary history of the bats and ectoparasites involved and the high specificity index of the interactions. The low centrality values may be associated with low connectivity and a high degree of specialization. This study provides relevant information on bat­parasite interactions in an urban environment, highlighting the need for further studies to improve our understanding of host­parasite interaction networks.

Larval morphology of the avian parasitic genus Passeromyia: playing hide and seek with a parastomal bar.

The enigmatic larvae of the Old World genus Passeromyia Rodhain & Villeneuve, 1915 (Diptera: Muscidae) inhabit the nests of birds as saprophages or as haematophagous agents of myiasis among nestlings. Using light microscopy, confocal laser scanning microscopy and scanning electron microscopy, we provide the first morphological descriptions of the first, second and third instar of P. longicornis (Macquart, 1851) (Diptera: Muscidae), the first and third instar of P. indecora (Walker, 1858) (Diptera: Muscidae), and we revise the larval morphology of P. heterochaeta (Villenueve, 1915) (Diptera: Muscidae) and P. steini Pont, 1970 (Diptera: Muscidae). We provide a key to the third instar of examined species (excluding P. steini and P. veitchi Bezzi, 1928 (Diptera: Muscidae)). Examination of the cephaloskeleton revealed paired rod-like sclerites, named 'rami', between the lateral arms of the intermediate sclerite in the second and third instar larva. We reveal parastomal bars fused apically with the intermediate sclerite, the absence of which has so far been considered as apomorphic for second and third instar muscid larvae. Examination of additional material suggests that modified parastomal bars are not exclusive features of Passeromyia but occur widespread in the Muscidae, and rami may occur widespread in the Cyclorrhapha.

The use of RNA interference for the management of arthropod pests in livestock farms.

Pest management in farm animals is an important action to contain economic damage to livestock production and prevent transmission of severe diseases to the stock. The use of chemical insecticides is still the most common approach followed by farmers; however, avoiding possible toxic effects on animals is a fundamental task for pest control measures compatible with animal well-being. Moreover, legal constraints and insurgence of resistance by target species to the available insecticidal compounds are increasingly complicating farmers' operations. Alternatives to chemical pesticides have been explored with some promising results in the area of biological control or the use of natural products as sprays. The application of RNA interference techniques has enabled the production of new means of pest control in agriculture, and it is opening a promising avenue for controlling arthropod pests of livestock. Transcript depletion of specific target genes of the recipient organisms is based on the action of double-strand RNAs (dsRNA) capable of impairing the production of fundamental proteins. Their mode of action, based on the specific recognition of short genomic sequences, is expected to be highly selective towards non-target organisms potentially exposed; in addition, there are physical and chemical barriers to dsRNA uptake by mammalian cells that render these products practically innocuous for higher animals. Summarising existing literature on gene silencing for main taxa of arthropod pests of livestock (Acarina, Diptera, Blattoidea), this review explores the perspectives of practical applications of dsRNA-based pesticides against the main pests of farm animals. Knowledge gaps are summarised to stimulate additional research in this area.

Latitudinal and anthropogenic effects on the structuring of networks linking blood-feeding flies and their vertebrate hosts.

Biting flies (Diptera) transmit pathogens that cause many important diseases in humans as well as domestic and wild animals. The networks of feeding interactions linking these insects to their hosts, and how they vary geographically and in response to human land-use, are currently poorly documented but are relevant to understanding cross-species disease transmission. We compiled a database of biting Diptera-host interactions from the literature to investigate how key interaction network metrics vary latitudinally and with human land-use. Interaction evenness and H2' (a measure of the degree of network specificity) did not vary significantly with latitude. Compared to near-natural habitats, interaction evenness was significantly lower in agricultural habitats, where networks were dominated by relatively few species pairs, but there was no evidence that the presence of humans and their domesticated animals within networks led to systematic shifts in network structure. We discuss the epidemiological relevance of these results and the implications for predicting and mitigating future spill-over events.

Methoprene treatment and its effect on male reproductive organ size and female remating in a fruit fly.

Methoprene, a juvenile hormone analog, is used to accelerate sexual maturation in males of species of economic importance in support to the sterile insect technique (SIT). In the SIT, mass-reared sterile males are released into the field and need to survive until they reach sexual maturation, find a wild female, mate with her and then induce female sexual refractoriness, so she will not remate with a wild counterpart. The use of methoprene shortens the time between release and copulation. However, in South American fruit flies, Anastrepha fraterculus, the ability of methoprene-treated males to inhibit female remating has been shown to be lower than wild males, when methoprene was applied by pupal immersion or topical application. Here we evaluated the possibility of incorporating methoprene into the male diet at different doses and the ability of those males to inhibit female remating, as well as the effect of methoprene on male reproductive organ size, due to the possible correlation between male accessory gland size and their content, and the role of male accessory gland proteins in female inhibition. We found that A. fraterculus males fed with methoprene in the adult protein diet at doses as high as 1% were less likely to inhibit female remating, however, at all other lower doses males had the same ability as untreated males to inhibit female remating. Males fed with methoprene had bigger male accessory glands and testes compared to methoprene-deprived males. We demonstrate that the incorporation of methoprene in adult male diets is possible in this species and potentially useful as a post-teneral, pre-release supplement at doses as low as 0.01%. Even at higher doses, the percentage of females remating after 48 h from the first copulation is sufficiently low in this species so as not compromise the efficiency of the SIT.

Determinants of the composition of ectoparasitic flies of bats (Diptera: Streblidae, Nycteribiidae) in the Amazon and Cerrado landscape scales and ecotonal areas.

The high diversity of bats in the Neotropics is primarily associated with various ectoparasite species on their bodies. Interactions between these animals need to be comprehensively investigated at landscape scales, focusing on understanding the patterns of diversity of species. We sought to evaluate, througt bat captures and ectoparasite sampling, the determinants of the composition of ectoparasitic flies species present in bats in in the Amazon and Cerrado biomes and ecotone areas. We used a generalized dissimilarity model (GDM) to verify what factors explained the composition of ectoparasitic flies of bats using landscape metrics, geographic distance, biome, and host composition. Twenty-four bat species haboured a total of 33 species of ectoparasitic flies. Host composition was the best predictor of fly composition, followed by the environmental variables and by biome. Geographical distance presented negligible effects. Studies on large scales tend to reveal a wide diversity of ectoparasitic flies. Host composition, as the best predictor of fly composition, may be associated with interspecific characteristics among species. We recommend studies focusing on the landscape to understand better the parasitic associations of bats and their distribution across environments.

Biological responses of Chironomus sancticaroli to exposure to naturally aged PP microplastics under realistic concentrations.

Microplastic (MP) is yet another form of chronic anthropogenic contribution to the environment. MPs are plastic particles (<5 mm) that have been widely found in the most diverse natural environments, but their real impacts on ecosystems are still under investigation. Here, we studied the toxicity of naturally aged secondary polypropylene (PP) MPs after constant exposure to ultraviolet radiation (26 µm) to the third instar larvae of Chironomus sancticaroli, a dipteran species. The concentrations tested were 13.5; 67.5; and 135 items g-1 of dry sediment. C. sancticaroli organisms were investigated for fragment ingestion, mortality and changes in enzymatic biomarkers after 144 h of exposure. The organisms were able to ingest MPs from the first 48 h, and the amount of items internalized was dose-dependent and time-dependent. Overall, the results show that mortality was low, being significant at the lowest and highest concentrations (13.5 and 135 items g-1). Regarding changes in biochemical markers, after 144 h MDA and CAT activities were both significantly altered (increased and reduced, respectively), while SOD and GST levels were unchanged. In the present study, naturally aged polypropylene MPs induced biochemical toxicity in C. sancticaroli larvae, with toxicity being higher according to exposure time and particle concentration.