Many insects contain diverse gut microbial communities. While several studies have focused on a single or small group of species, comparative studies of phylogenetically diverse hosts can illuminate general patterns of host-microbiota associations. In this study, we tested the hypotheses that (i) host diet and (ii) host taxonomy structure intestinal bacterial community composition among insects. We used published 16S rRNA gene sequence data for 58 insect species in addition to four beetle species sampled from the Sevilleta National Wildlife Refuge to test these hypotheses. Overall, gut bacterial species richness in these insects was low. Decaying wood xylophagous insects harboured the richest bacterial gut flora (102.8 species level operational taxonomic units (OTUs)/sample ± 71.7, 11.8 ± 5.9 phylogenetic diversity (PD)/sample), while bees and wasps harboured the least rich bacterial communities (11.0 species level OTUs/sample ± 5.4, 2.6 ± 0.8 PD/sample). We found evidence to support our hypotheses that host diet and taxonomy structure insect gut bacterial communities (P < 0.001 for both). However, while host taxonomy was important in hymenopteran and termite gut community structure, diet was an important community structuring factor particularly for insect hosts that ingest lignocellulose-derived substances. Our analysis provides a baseline comparison of insect gut bacterial communities from which to test further hypotheses concerning proximate and ultimate causes of these associations.

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Screening for emotional distress is important, but not widely available. This study assesses the utility of the Refugee Health Screener 15 (RHS-15) in a public health setting. Refugee Health Screener 15 and diagnostic proxy (DP) instruments assessing anxiety, depression, and posttraumatic stress disorder were administered to refugees from 3 countries at their public health examination. Properties of the RHS-15 and its components were evaluated utilizing appropriate methods. Scale Cronbach α was 0.95, and a factor analysis identified 1 factor accounting for 66% of scale variance. Refugee Health Screener 15 scores and cases discriminated between refugee groups similar to DPs. Refugee Health Screener 15 case sensitivity and specificity to DPs were acceptable (≥0.87/0.77). A shorter, 13-item component had acceptable metric properties. The RHS-15 appears to be a valid screener for emotional distress of refugees. The 13-item scale may be more efficient and as efficacious for case identification. The critical public health need and recommendations for implementation are discussed.

The effects of larval and pupal thermal regime on adult transcuticular water loss rates and epicuticular hydrocarbon composition in Drosophila pseudoobscura were determined. Temperatures encountered by the larval stage had no effect, but flies emerging from pupae maintained at 24°C exhibited significantly lower cuticular permeabilities than those emerging from pupae maintained at 17°C. More than 50% of the variance in cuticular permeability was accounted for by variation in the proportion of n-pentacosadiene in the epicuticular hydrocarbons. High transcuticular water loss rates were correlated with higher proportions of relatively short-chain, methyl-branched alkanes and alkadienes. High proportions of longer chain lengths of both branched alkanes and alkadienes were associated with lower cuticular permeabilities. The molecular basis for these findings is discussed.

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