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Abstract Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees (Apis mellifera), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeepers and 165 meliponiculturists participated in the 2-year survey (2016–2017 and 2017–2018). On average, 30.4% of honey bee colonies and 39.6% of stingless bee colonies were lost per year across the region. Summer losses were higher than winter losses in stingless bees (30.9% and 22.2%, respectively) but not in honey bees (18.8% and 20.6%, respectively). Colony loss increased with operation size during the summer in both honey bees and stingless bees and decreased with operation size during the winter in stingless bees. Furthermore, losses differed significantly between countries and across years for both beekeepers and meliponiculturists. Overall, winter losses of honey bee colonies in Latin America (20.6%) position this region between Europe (12.5%) and the United States (40.4%). These results highlight the magnitude of bee colony losses occurring in the region and suggest difficulties in maintaining overall colony health and economic survival for beekeepers and meliponiculturists. 

Abstract Lithium has been considered a potential acaricidal agent against the honey bee (Apis mellifera) parasite Varroa. It is known that lithium suppresses elevated activity and regulates circadian rhythms and light response when administered to humans as a primary therapeutic chemical for bipolar disorder and to other bipolar syndrome model organisms, given the crucial role of timing in the bee's foraging activity and the alternating sunlight vs dark colony environment bees are exposed, we explored the influence of lithium on locomotor activity (LMA) and circadian rhythm of honey bees. We conducted acute and chronic lithium administration experiments, altering light conditions and lithium doses to assess LMA and circadian rhythm changes. We fed bees one time 10 μl sucrose solution with 0, 50, 150, and 450 mM LiCl in the acute application experiment and 0, 1, 5, and 10 mmol/kg LiCl ad libitum in bee candy in the chronic application experiment. Both acute and chronic lithium treatments significantly decreased the induced LMA under constant light. Chronic lithium treatment disrupted circadian rhythmicity in constant darkness. The circadian period was lengthened by lithium treatment under constant light. We discuss the results in the context ofVarroacontrol and lithium's effect on bipolar disorder. 

Abstract Most freshwater habitats have been substantially affected by anthropogenic factors such as fish introductions, plastic pollution, and river regulation. Urban rivers are highly vulnerable to impacts associated with land use changes resulting from increasing urbanization, including altering habitat and establishing aquatic biological communities in these areas. In turn, the introduction of exotic species into sensitive and threatened ecosystems such as tropical urban streams and their rapid establishment, such asPterygoplichthys multiradiatus, was used as an ecological model to determine the relative population size of the species. Also, the species was used to evaluate the presence of microplastics (MPs) in the gastrointestinal tract (GIT) of fish in rivers with different land use history. Our results showed significant differences in pleco abundance between areas with high and low urban (LU) development in the watersheds. The study demonstrated that abiotic environmental factors directly influence the relative abundance of plecos at the range and watershed scales. In a total of 42 fish examined, only 85.7% showed MPs retained in the GIT, with fibers and fragments being the most common. A total of 22 pieces of microplastic were identified with Nile Red staining by slide analysis. A significant difference was found between the abundance of microplastic ingested per total fish length between streams with high and LU development reaches. Therefore, in relatively small amounts, microplastic ingestion appears to be common inP. multiradiatusspecies, regardless of the habitat in which they are found and the diet present. 

Abstract The effects of acute sublethal doses of coumaphos, an acaricide used againstVarroa destructorinfestation in beekeeping, on the locomotor activities of four native honeybee subspecies of Türkiye including two ecotypes (Carniolan honeybee -A. m. carnica, Syrian honeybee -A. m. syriaca, Caucasian honeybee-A. m. caucasica, and Muğla and Yığılca ecotypes of Anatolian honeybeeA. m. anatoliaca) were investigated using an individual locomotor activity monitoring system. Analysis of locomotor activity data in the first 12-h, last 12-h, and 24-h time periods showed that bees fromcaucasicaandcarnicasubspecies were not affected by coumaphos at all three acute doses (1, 2, and 5 μg coumaphos in 10 μl sucrose syrup for each bee). In contrast, bees fromA. m. syriacasubspecies showed significantly elevated locomotor activity levels at 2 and 5 μg coumaphos doses within the first 12 h. Bees from both Muğla and Yığılca ecotypes ofanatoliacasubspecies also showed elevated locomotor activity levels at 5 μg coumaphos dose but the magnitude of increase was lower in these ecotypes compared to that seen insyriacasubspecies in the first 12-h period. In general, increasing doses of coumaphos resulted in increased locomotor activity (locomotor activity), with differences in sensitivity across honeybee populations. Possible mechanisms underlying this variance and suggestions for further studies are discussed. 

Neuronal signals mediated by the biogenic amine serotonin underlie critical survival strategies across the animal kingdom. This investigation identified a group of serotonergic cells in the panpulmonate snail Biomphalaria glabrata that appear to be homologous to neurons that mediate withdrawal responses in other gastropod taxa. It is proposed that an ancient withdrawal circuit has been highly conserved in three major gastropod lineages. 

Mechanosensory neurons located across the body surface respond to tactile stimuli and elicit diverse behavioral responses, from relatively simple stimulus location-aimed movements to complex movement sequences. How mechanosensory neurons and their postsynaptic circuits influence such diverse behaviors remains unclear. We previously discovered thatDrosophilaperform a body location-prioritized grooming sequence when mechanosensory neurons at different locations on the head and body are simultaneously stimulated by dust (Hampel et al., 2017; Seeds et al., 2014). Here, we identify nearly all mechanosensory neurons on theDrosophilahead that individually elicit aimed grooming of specific head locations, while collectively eliciting a whole head grooming sequence. Different tracing methods were used to reconstruct the projections of these neurons from different locations on the head to their distinct arborizations in the brain. This provides the first synaptic resolution somatotopic map of a head, and defines the parallel-projecting mechanosensory pathways that elicit head grooming. 

Titanium dioxide is a type of nanoparticle that is composed of one titanium atom and two oxygen atoms. One of its physicochemical activities is photolysis, which produces different reactive oxygen species (ROS). Atya lanipes shrimp affect detrital processing and illustrate the potential importance of diversity and nutrient availability to the rest of the food web. It is essential in removing sediments, which have an important role in preventing eutrophication. This study aimed to determine the toxic effect of changes in behavior and levels of oxidative stress due to exposure to titanium dioxide nanoparticles in Atya lanipes and to determine the effective concentration (EC50) for behavioral variables. The concentrations of TiO2 NPs tested were 0.0, 0.50, 1.0, 2.0, and 3.0 mg/L with the positive controls given 100 µg/L of titanium and 3.0 mg/L of TiO2 NPs ± 100 µg/L of titanium. After 24 h of exposure, significant hypoactivity was documented. The EC50 was determined to be a concentration of 0.14 mg/L. After the exposure to 10 mg/L of TiO2 NPs, oxidative stress in gastrointestinal and nervous tissues was documented. The toxic effects of this emerging aquatic pollutant in acute exposure conditions were characterized by sublethal effects such as behavior changes and oxidative stress. 

The neglected tropical disease schistosomiasis impacts over 700 million people globally. Schistosoma mansoni , the trematode parasite that causes the most common type of schistosomiasis, requires planorbid pond snails of the genus Biomphalaria to support its larval development and transformation to the cercarial form that can infect humans. A greater understanding of neural signaling systems that are specific to the Biomphalaria intermediate host could lead to novel strategies for parasite or snail control. This study examined a Biomphalaria glabrata neural channel that is gated by the neuropeptide FMRF-NH 2 . The Biomphalaria glabrata FMRF-NH 2 gated sodium channel ( Bgl- FaNaC) amino acid sequence was highly conserved with FaNaCs found in related gastropods, especially the planorbid Planorbella trivolvis (91% sequence identity). In common with the P . trivolvis FaNaC, the B . glabrata channel exhibited a low affinity (EC 50 : 3 x 10 −4 M) and high specificity for the FMRF-NH 2 agonist. Its expression in the central nervous system, detected with immunohistochemistry and in situ hybridization, was widespread, with the protein localized mainly to neuronal fibers and the mRNA confined to cell bodies. Colocalization of the Bgl- FaNaC message with its FMRF-NH 2 agonist precursor occurred in some neurons associated with male mating behavior. At the mRNA level, Bgl- FaNaC expression was decreased at 20 and 35 days post infection (dpi) by S . mansoni . Increased expression of the transcript encoding the FMRF-NH 2 agonist at 35 dpi was proposed to reflect a compensatory response to decreased receptor levels. Altered FMRF-NH 2 signaling could be vital for parasite proliferation in its intermediate host and may therefore present innovative opportunities for snail control. 

Introduction Interest for bee microbiota has recently been rising, alleviating the gap in knowledge in regard to drivers of solitary bee gut microbiota. However, no study has addressed the microbial acquisition routes of tropical solitary bees. For both social and solitary bees, the gut microbiota has several essential roles such as food processing and immune responses. While social bees such as honeybees maintain a constant gut microbiota by direct transmission from individuals of the same hive, solitary bees do not have direct contact between generations. They thus acquire their gut microbiota from the environment and/or the provision of their brood cell. To establish the role of life history in structuring the gut microbiota of solitary bees, we characterized the gut microbiota of Centris decolorata from a beach population in Mayagüez, Puerto Rico. Females provide the initial brood cell provision for the larvae, while males patrol the nest without any contact with it. We hypothesized that this behavior influences their gut microbiota, and that the origin of larval microbiota is from brood cell provisions. Methods We collected samples from adult females and males of C. decolorata ( n  = 10 each, n  = 20), larvae ( n  = 4), and brood cell provisions ( n  = 10). For comparison purposes, we also sampled co-occurring female foragers of social Apis mellifera ( n  = 6). The samples were dissected, their DNA extracted, and gut microbiota sequenced using 16S rRNA genes. Pollen loads of A. mellifera and C. decolorata were analyzed and interactions between bee species and their plant resources were visualized using a pollination network. Results While we found the gut of A. mellifera contained the same phylotypes previously reported in the literature, we noted that the variability in the gut microbiota of solitary C. decolorata was significantly higher than that of social A. mellifera . Furthermore, the microbiota of adult C. decolorata mostly consisted of acetic acid bacteria whereas that of A. mellifera mostly had lactic acid bacteria. Among C. decolorata , we found significant differences in alpha and beta diversity between adults and their brood cell provisions (Shannon and Chao1 p  < 0.05), due to the higher abundance of families such as Rhizobiaceae and Chitinophagaceae in the brood cells, and of Acetobacteraceae in adults. In addition, the pollination network analysis indicated that A. mellifera had a stronger interaction with Byrsonima sp. and a weaker interaction with Combretaceae while interactions between C. decolorata and its plant resources were constant with the null model. Conclusion Our data are consistent with the hypothesis that behavioral differences in brood provisioning between solitary and social bees is a factor leading to relatively high variation in the microbiota of the solitary bee.