Effects of contaminants of emerging concern on Megaselia scalaris (Lowe, Diptera: Phoridae) and its microbial community.

Drought, rising temperatures, and expanding human populations are increasing water demands. Many countries are extending potable water supplies by irrigating crops with wastewater. Unfortunately, wastewater contains biologically active, long-lived pharmaceuticals, even after treatment. Run-off from farms and wastewater treatment plant overflows contribute high concentrations of pharmaceuticals to the environment. This study assessed the effects of common pharmaceuticals on a cosmopolitan saprophagous insect, Megaselia scalaris (Diptera: Phoridae). Larvae were reared on artificial diets spiked with contaminants of emerging concern (CECs) at environmentally relevant concentrations. Female flies showed no oviposition preference for treated or untreated diets. Larvae exposed to caffeine in diets showed increased mortality, and larvae fed antibiotics and hormones showed signs of slowed development, especially in females. The normal sex ratio observed in M. scalaris from control diets was affected by exposure to caffeine and pharmaceutical mixture treatments. There was an overall effect of treatment on the flies' microbial communities; notably, caffeine fed insects displayed higher microbial variability. Eight bacterial families accounted for approximately 95% of the total microbes in diet and insects. Our results suggest that CECs at environmentally relevant concentrations can affect the biology and microbial communities of an insect of ecological and medical importance

Specificity Between Lactobacilli And Hymenopteran Hosts Is The Exception Rather Than The Rule

Lactobacilli (Lactobacillales: Lactobacillaceae) are well known for their roles in food fermentation, as probiotics, and in human health, but they can also be dominant members of the microbiota of some species of Hymenoptera (ants, bees, and wasps). Honey bees and bumble bees associate with host-specific lactobacilli, and some evidence suggests that these lactobacilli are important for bee health. Social transmission helps maintain associations between these bees and their respective microbiota. To determine whether lactobacilli associated with social hymenopteran hosts are generally host specific, we gathered publicly available Lactobacillus 16S rRNA gene sequences, along with Lactobacillus sequences from 454 pyrosequencing surveys of six other hymenopteran species (three sweat bees and three ants). We determined the comparative secondary structural models of 16S rRNA, which allowed us to accurately align the entire 16S rRNA gene, including fast-evolving regions. BLAST searches and maximum-likelihood phylogenetic reconstructions confirmed that honey and bumble bees have host-specific Lactobacillus associates. Regardless of colony size or within-colony oral sharing of food (trophallaxis), sweat bees and ants associate with lactobacilli that are closely related to those found in vertebrate hosts or in diverse environments. Why honey and bumble bees associate with host-specific lactobacilli while other social Hymenoptera do not remains an open question. Lactobacilli are known to inhibit the growth of other microbes and can be beneficial whether they are coevolved with their host or are recruited by the host from environmental sources through mechanisms of partner choice.National Science Foundation PRFB-1003133, DEB-0919519Texas Higher Education Coordinating Board 01923, National Institutes of Health GM067317Integrative BiologyCellular and Molecular BiologyCenter for Computational Biology and BioinformaticsBrackenridge Field Laborator

Draft Genome Sequences of Four Saccharibacter sp. Strains Isolated from Native Bees.

The genus Saccharibacter is currently understudied, with only one described species, Saccharibacter floricola, isolated from a flower. In an effort to better understand the microbes that come in contact with native bee pollinators, we isolated and sequenced four additional strains of Saccharibacter from native bees in the genera Melissodes and Anthophora These genomes range in size from 2,104,494 to 2,316,791 bp (mean, 2,246,664 bp) and contain between 1,860 and 2,167 (mean, 2,060) protein-coding genes

First screening of bacterial communities of Microdon myrmicae and its ant host: do microbes facilitate the invasion of ant colonies by social parasites?

Abstract Many studies have highlighted how numerous bacteria provide their hosts essential nutrients or protection against pathogens, parasites and predators. Nevertheless, the role of symbiotic microorganisms in the interactions between social insects and their parasites is still poorly known. Microdon (Diptera, Syrphidae) is a peculiar fly genus whose larvae are able to successfully infiltrate ant colonies and feed upon the ant brood. Using high throughput 16S rRNA gene amplicon sequencing, we provide the first microbiome survey of Mi. myrmicae larvae and larvae and workers of its host, Myrmica scabrinodis, collected from two sites in England. We analyzed the microbiome of the external surface of the cuticle and the internal microbiome of the body separately. The results clearly show that the Mi. myrmicae microbiome significantly differs from that of its host, while no substantial dissimilarity was detected across the microbiome of ant workers and ant larvae. Microdon myrmicae microbiome varies across the two analyzed sites suggesting that bacteria communities of Mi. myrmicae are derived from the environment rather than by horizontal transmission between hosts and parasites. Families Streptococcaceae, Carnobacteriaceae and Rizhobiaceae are dominant in My. scabrinodis, and Spiroplasma is dominant in ant workers. Microbiome of Mi. myrmicae larvae is mainly characterized by the family Anaplasmataceae, with Wolbachia as predominant genus. Interestingly, we found Serratia within both Mi. myrmicae and Myrmica larvae. Bacteria of this genus are known to produce a family of pyrazines commonly involved in ant communication, which could play a role in Microdon/ant interaction

Bacterial microbiomes from vertically-transmitted fungal inocula of the leaf-cutting ant Atta texana

Microbiome surveys provide clues for the functional roles of symbiotic microbial communities and their hosts. In this study, we elucidated bacterial microbiomes associated with the vertically transmitted fungal inocula (pellets) used by foundress queens of the leaf-cutting ant Atta texana as starter-cultures for new gardens. As reference microbiomes, we also surveyed bacterial microbiomes of foundress queens, gardens and brood of incipient nests. Pseudomonas, Acinetobacter, Propionibacterium and Corynebacterium were consistently present in high abundance in microbiomes. Some pellet and ant samples contained abundant bacteria from an Entomoplasmatales-clade, and a separate PCR-based survey of Entomoplasmatales bacteria in eight attine ant-genera from Brazil placed these bacteria in a monophyletic clade within the bacterial genus Mesoplasma. The attine ant-Mesoplasma association parallels a similar association between a closely related, monophyletic Entomoplasmatales-clade and army ants. Of thirteen A. texana nests surveyed, three nests with exceptionally high Mesoplasma abundance died, whereas the other nests survived. It is unclear whether Mesoplasma was the primary cause of mortality, or Mesoplasma became abundant in moribund nests for non-pathogenic reasons. However, the consistent and geographically widespread presence of Mesoplasma suggests an important functional role in the association with attine ants