Few biological phenomena provide such an elegant and straightforward example of evolution by natural selection as color mimicry among unrelated organisms. By mimicking the appearance of a heavily defended aposematic species, members of a second species gain protection from predators and, potentially, enhanced fitness. Mimicking a preexisting warning advertisement is economical because a potentially costly novel one can be avoided; simultaneously, the addition of more aposematic individuals enhances the overall warning effect. The better-known mimetic systems comprise tropical taxa, but here, we show a remarkable example of color mimicry in 7 species of blind, cyanide-generating millipedes endemic to the Appalachian Mountains of temperate North America. Because these millipedes lack eyes, there is no sexual selection or intraspecific signaling for coloration, providing an ideal system for mimicry studies. We document a Mü llerian symbiosis where unrelated species vary in color and pattern over geographical space but appear identical where they co-occur. By using spectral color data, estimations of evolutionary history, and detailed field observations of species abundance, we test 4 predictions of Mü llerian mimicry theory and begin to unravel the story of an elaborate mimetic diversification in the forests of Appalachia.aposematic ͉ reflectance ͉ Apheloriini ͉ Diplopoda ͉ Brachoria

SignificanceMany insects release volatile terpenes for chemical communication. However, the biosynthetic origin and evolution of these infochemicals are mostly unknown. We show that the harlequin bug, Murgantia histrionica, a stink bug pest (Hemiptera) of crucifer crops, produces a terpene aggregation pheromone by an enzyme that is unrelated to microbial and plant terpene synthases. M. histrionica terpene synthase activity is highly sex- and tissue-specific and makes a sesquiterpene alcohol, so far unknown in animals, as pheromone precursor. The enzyme evolved from ancestral isoprenyl diphosphate synthases and provides new evidence for de novo biosynthesis of terpenes in hemipteran insects. Knowledge of pheromone biosynthesis in stink bugs may lead to the development of new controls of these pests.

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Background: Species that are widespread throughout historically glaciated and currently nonglaciated areas provide excellent opportunities to investigate the role of Pleistocene climatic change on the distribution of North American biodiversity. Many studies indicate that northern animal populations exhibit low levels of genetic diversity over geographically widespread areas whereas southern populations exhibit relatively high levels. Recently, paleoclimatic data have been combined with niche-based distribution modeling to locate possible refugia during the Last Glacial Maximum. Using phylogeographic, population, and paleoclimatic data, we show that the distribution and mitochondrial data for the millipede genus Narceus are consistent with classical examples of Pleistocene refugia and subsequent post-glacial population expansion seen in other organismal groups.

The millipede family Xystodesmidae includes 486 species distributed primarily in temperate deciduous forests in North America and East Asia. Species diversity of the family is greatest in the Appalachian Mountains of the eastern United States, with 188 species. Although the group includes notable taxa such as those that are bioluminescent and others that display Müllerian mimicry, producing up to 600 mg of cyanide, basic alpha-taxonomy of the group is woefully incomplete and more than 50 species remain undescribed in the Appalachian Mountains alone. In order to establish a robust phylogenetic foundation for addressing compelling evolutionary questions and describing species diversity, we assembled the largest species phylogeny (in terms of species sampling) to date in the Diplopoda. We sampled 49 genera (out of 57) and 247 of the species in the family Xystodesmidae, recollecting fresh material from historical type localities and discovering new species in unexplored regions. Here, we present a phylogeny of the family using six genes (four mitochondrial and two nuclear) and include pivotal taxa omitted from previous studies including Nannaria, Erdelyia, taxa from East Asia, and 10 new species. We show that 6 of the 11 tribes are monophyletic, and that the family is paraphyletic with respect to the Euryuridae and Eurymerodesmidae. Prior supraspecific classification is in part inconsistent with the phylogeny and convergent evolution has caused artificial genera to be proposed. Subspecific classification is likewise incongruent with phylogeny and subspecies are consistently not sister to conspecifics. The phylogeny is used as a basis to update the classification of the family, diagnose monophyletic groups, and to inform species hypotheses.

La Crosse virus (LACV), a leading cause of arboviral encephalitis in children in the United States, is emerging in Appalachia. For local arboviral surveillance, mosquitoes were tested. LACV RNA was detected and isolated from Aedes japonicus mosquitoes. These invasive mosquitoes may significantly affect LACV range expansion and dynamics.

Brachycybe (Wood) is a genus of fungivorous millipedes. To date, the fungal associates of these millipedes have never been characterized. In an attempt to resolve these relationships, culture-based approaches combined with DNA barcode sequencing were used. Sampling of 313 individuals collected from three of four B. lecontii clades and 20 sites across seven states uncovered at least 183 genera in 40 orders from four fungal phyla. At least seven putative new species were recovered in this study, despite the use of more classical culture-based approaches. Three of these fungi were phylogenetically resolved using ITS + LSU and include two new species, aff. Fonsecaea sp., Mortierella aff. ambigua, and a new genus related to Apophysomyces. Overall, the results of this study highlight the vast amount of undescribed fungal biodiversity associated with millipedes. Twelve fungal genera from nine orders showed high connectivity across the entire B. lecontii-associated fungal network, indicating a central role for these fungi in their association with these millipedes. These twelve include the two putative new species described above. The ecology of these and other fungal associates were also explored, using fungal cohort pairings and entomopathogenicity trials. Over 40% of all fungal pairings resulted in competitive interactions, a majority of which involved inhibition or overgrowth by fungi in the Hypocreales and Polyporales, respectively. The abundance of these competitive interactions in these two orders indicate differing ecological strategies. Hypocreales used chemical warfare to competitively exclude other fungi, while Polyporales physically overgrew their competitors. Mucoromycotan fungi used a similar strategy to the Polyporales. Results of a series of entomopathogenicity trials indicated that B. lecontii was less susceptible to entomopathogenic Hypocreales than an insect model (Galleria mellonella), even though these fungi are known to attack several classes of arthropods. Furthermore, the absence of a negative interaction between B. lecontii and entomopathogenic Hypocreales may indicate a beneficial relationship. When challenged with Polyporales, B. lecontii exhibited high mortality, while G. mellonella was unaffected. This stands in sharp contrast to previous casual observations of the feeding behavior of B. lecontii. Recent discoveries of previously overlooked fungal diversity have been groundbreaking and hint at substantial cryptic fungal biodiversity across the globe. The 200-300 million-year-old association between fungi and the Colobognatha, which includes Brachycybe lecontii, provides an ideal system to uncover biodiversity and examine function of these fungi in a highly understudied and ancient association.

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