Coprophagous Insects and the Ecology of Infectious Diseases of Wildlife.

A diversity of macro- and microparasitic species exert strong influences on wildlife population density, community structure, and ecosystem functioning, all through their impacts on individual host fitness. Through consuming, manipulating, and relocating wildlife feces, over 7,000 species of coprophagous dung beetles interact with a staggering diversity of wildlife parasites with fecal-oral transmission in ways that both increase and decrease transmission. Here, we review the mechanisms by which dung beetles influence micro- and macroparasite transmission and outline a future research framework that integrates theory and empirical insights to advance our understanding of how these relationships may interact with ongoing environmental change drivers to further influence wildlife populations and community structure. Any organism that significantly influences parasite transmission will impact multiple levels of biological organization. Therefore, improving our understanding of the role of dung beetle interactions within disease ecology will be key to future efforts to understand the overall dynamics of infection in wildlife and how parasites contribute to the maintenance of ecosystem structure and function and evolutionary processes in wild animals.

Molecular and histological characterization of primary (betaproteobacteria) and secondary (gammaproteobacteria) endosymbionts of three mealybug species.

Microscopic localization of endosymbiotic bacteria in three species of mealybug (Pseudococcus longispinus, the long-tailed mealybug; Pseudococcus calceolariae, the citrophilus mealybug; and Pseudococcus viburni, the obscure mealybug) showed these organisms were confined to bacteriocyte cells within a bacteriome centrally located within the hemocoel. Two species of bacteria were present, with the secondary endosymbiont, in all cases, living within the primary endosymbiont. DNA from the dissected bacteriomes of all three species of mealybug was extracted for analysis. Sequence data from selected 16S rRNA genes confirmed identification of the primary endosymbiont as "Candidatus Tremblaya princeps," a betaproteobacterium, and the secondary endosymbionts as gammaproteobacteria closely related to Sodalis glossinidius. A single 16S rRNA sequence of the primary endosymbiont was found in all individuals of each mealybug species. In contrast, the presence of multiple divergent strains of secondary endosymbionts in each individual mealybug suggests different evolutionary and transmission histories of the two endosymbionts. Mealybugs are known vectors of the plant pathogen Grapevine leafroll-associated virus 3. To examine the possible role of either endosymbiont in virus transmission, an extension of the model for interaction of proteins with bacterial chaperonins, i.e., GroEL protein homologs, based on mobile-loop amino acid sequences of their GroES homologs, was developed and used for analyses of viral coat protein interactions. The data from this model are consistent with a role for the primary endosymbiont in mealybug transmission of Grapevine leafroll-associated virus 3.

Evolutionary relationships among the Scarabaeini (Coleoptera: Scarabaeidae) based on combined molecular and morphological data.

The Scarabaeini is an old world tribe of ball-rolling dung beetles that have origins dating back to at least the mid-upper Miocene (19-8 million years ago). The tribe has received little to no attention in morphological or molecular phylogenetics. We obtained sequence data from the mitochondrial cytochrome oxidase subunit I (1,197 bp) and 16S ribosomal RNA (461 bp) genes for 25 species of the Scarabaeini in an attempt to further resolve broad phylogenetic relationships within this tribe. Sequence data from both markers along with 216 morphological and 3 biological characters were analysed separately and combined. Independent analyses showed poorly resolved trees with many of the intermediate and basal nodes collapsed by low bootstrap values. Many sites in both genes exhibited strong A+T nucleotide bias and high interlineage divergences. The combined analysis revealed a number of well supported relationships such as the monophyly of the nocturnal species Scarabaeus satyrus, S. [Neateuchus] proboscideus, and S. zambesianus. Furthermore, the total evidence tree suggested to elevate S. (Pachysoma) to the status of an independent genus, Pachysoma, as a sister taxon to a clade containing Pachylomerus femoralis and Scarabaeus sensu lato. Within the latter, the following subgenera were maintained by the combination of data sets: S. (Scarabaeolus), S. (Sceliages), and S. (Kheper). Both, feeding specialisation and food relocation behaviour, were inferred to be polyphyletic in the Scarabaeini. Total evidence analysis found no support for common ancestry of Scarabaeini and Eucraniini.

Testing phylogeographic predictions on an active volcanic island: Brachyderes rugatus (Coleoptera: Curculionidae) on La Palma (Canary Islands).

Volcanic islands with well-characterized geological histories can provide ideal templates for generating and testing phylogeographic predictions. Many studies have sought to utilize these to investigate patterns of colonization and speciation within groups of closely related species across a number of islands. Here we focus attention within a single volcanic island with a well-characterized geological history to develop and test phylogeographic predictions. We develop phylogeographic predictions within the island of La Palma of the Canary Islands and test these using 69 haplotypes from 570 base pairs of mitochondrial DNA cytochrome oxidase II sequence data for 138 individuals of Brachyderes rugatus rugatus, a local endemic subspecies of curculionid beetle occurring throughout the island in the forests of Pinus canariensis. Although geological data do provide some explanatory power for the phylogeographic patterns found, our network-based analyses reveal a more complicated phylogeographic history than initial predictions generated from data on the geological history of the island. Reciprocal illumination of geological and phylogeographic history is also demonstrated with previous geological speculation gaining phylogeographic corroboration from our analyses.