Attractant Activity of Host-Related Chemical Blends on the Poultry Red Mite at Different Spatial Scales.

Many blood-feeding arthropods use volatile organic compounds (VOCs) to detect their vertebrate hosts. The role of chemical interactions in mediating the behavior of hematophagous insects and ticks has been investigated before but remains poorly understood in hematophagous mesostigmatic mites. The poultry red mite Dermanyssus gallinae is an obligatory blood-sucking mesostigmatic mite that feeds on birds and causes damage in poultry farms. We characterized the attractive response of D. gallinae to candidate VOCs previously reported from the odor emitted by living hens. We performed in-vitro choice-test bioassays as well as semi-field and field trials using baited and unbaited traps, in the presence and absence of hens. Among different tested combinations of VOCs, a blend of 5 VOCs (mix1.0) was significantly attractive to our reference population of D. gallinae in vitro, whereas the same individual compounds tested alone were not attractive. Ammonia was attractive on its own and increased the mix1.0 attractiveness. The attractiveness of mix1.0 was confirmed at 'natural' spatial scales in the absence of hens both at the lab and on the farm that provided the reference population. The presence of hens inhibited the mix1.0 attractiveness. The attractive power of mix1.0 was not found in other farms. This research is an important step to advance our understanding of host-parasite interactions in hematophagous mesostigmatic mites and paves the way for developing alternative control tools against D. gallinae by interfering with chemical interactions. Moreover, it underlines the importance of assessing kairomonal activity on different pest populations when developing attract-and-kill systems.

Cephalocyclus iohannisgabrielis (Coleoptera: Scarabaeidae: Aphodiinae), a new species from Oaxaca, Mexico.

The genus Cephalocyclus Dellacasa, Gordon Dellacasa, 1998 (Coleoptera: Scarabaeidae: Aphodiinae: Aphodiini) was created for 10 species distributed in southern United States of America and Mesoamerica. Subsequently, 14 species were described or added to this genus (Dellacasa et al. 2000, 2007, 2011, 2013; Deloya Ibáñez-Bernal 2000; Minor et al. 2015). A.A.-J. collected a large series of specimens from Oaxaca (Mexico) belonging to a new species of Cephalocyclus described here. The specimens of this new species came from "El Cerro del Aguila" in the Mixteca Region, between 2800-3250 m. All specimens were collected with pitfall traps baited with human excrement.

Modulation of feed composition is able to make hens less attractive to the poultry red mite Dermanyssus gallinae.

The poultry red mite (PRM) is an obligatory haematophagous pest that causes substantial economic losses in poultry worldwide. The PRM does not live on the host but in the bird's environment and must find its host remotely. Hence, manipulating chicken odours is of interest. Several crude plant-originating volatile organic compounds (VOCs) have already been shown as repellent to Dermanyssus gallinae. We aimed to test whether these VOCs can interfere with PRM host-seeking behaviour by their oral administration to the poultry. The objectives were to determine (1) if hen odours are modified by supplemented feed ingestion and (2) if such treatment makes hens less attractive to the PRM. Chemical characterization by gas chromatography-mass spectrometry of the hen odour was conducted before and after the hens ingested the supplemented feed. The chromatograms obtained show that hen odour was substantially modified after the hens consumed it. Among the molecules recurrently detected from the supplemented hens, 26% were nearly absent in the unsupplemented hens. Behavioural choice tests to compare the effect of the modified and unmodified-host odours on the PRM show that some of the plant-originating emitted VOCs and the modified whole-hen odours were repellent to the PRM.

Gonaphodioides zempoaltepetlensis (Coleoptera: Scarabaeidae: Aphodiinae), a new species from Oaxaca, Mexico.

The genus Gonaphodioides Dellacasa, Dellacasa, Gordon, 2012 (Coleoptera: Scarabaeidae: Aphodiinae: Aphodiini) was created for seven species distributed in Mesoamerica and South America. Subsequently, G. cartwrighti Dellacasa, Dellacasa, Gordon, 2013 was described from El Salvador (Dellacasa et al. 2013).

An unusual new species of Canthidium (Coleoptera: Scarabaeidae: Scarabaeinae) from Oaxaca, Mexico.

In this paper we describe Canthidium quercetorum new species (Coleoptera: Scarabaeidae: Scarabaeinae), a species that inhabits dry oak forest in the Mexican state of Oaxaca, between 2100 and 2300 m above sea level. Photographs and an illustration of the habitus and a distribution map are provided. The unusual distribution and ecology of this species are discussed. An updated key for the genus in Mexico and the United States of America is also presented.

Dung beetle vicariant speciation in the mountains of Oaxaca, Mexico, with a description of a new species of Phanaeus (Coleoptera, Geotrupidae, Scarabaeidae).

An analysis of vicariant speciation of Geotrupes and Phanaeus (Coleoptera, Geotrupidae, Scarabaeidae) from the mountains of Oaxaca, Mexico is undertaken. The new species of dung beetle (Coleoptera: Scarabaeidae) from Oaxaca, Mexico, Phanaeus dionysiussp. n. is described. Photos of the habitus and a distribution map are provided. Phanaeus malyi Arnaud is revalidated. An updated key for the Phanaeus endymion species group and new localities are also presented. An updated key for the Geotrupes of Oaxaca and new locality records are also submitted.

ResumenSe realiza un análisis de especiación vicariante de Geotrupes y Phanaeus (Coleoptera, Geotrupidae, Scarabaeidae) de las montañas de Oaxaca, México. La siguiente especie nueva de escarabajo estercolero (Coleoptera: Scarabaeidae) se describe de Oaxaca: Phanaeus dionysiussp. n. Se incluyen fotografías, así como el respectivo mapa de distribución. Se revalida a la especie Phanaeus malyi Arnaud. Se presenta una clave puesta al día del grupo de especies de Phanaeus endymion, así como nuevos registros de distribución. Se incluye también una clave puesta al día para los Geotrupes de Oaxaca.

High variability of dung beetle diversity patterns at four mountains of the Trans-Mexican Volcanic Belt.

Insect diversity patterns of high mountain ecosystems remain poorly studied in the tropics. Sampling dung beetles of the subfamilies Aphodiinae, Scarabaeinae, and Geotrupinae was carried out at four volcanoes in the Trans-Mexican Volcanic Belt (TMVB) in the Mexican transition zone at 2,700 and 3,400 MASL, and on the windward and leeward sides. Sampling units represented a forest-shrubland-pasture (FSP) mosaic typical of this mountain region. A total of 3,430 individuals of 29 dung beetle species were collected. Diversity, abundance and compositional similarity (CS) displayed a high variability at all scales; elevation, cardinal direction, or FSP mosaics did not show any patterns of higher or lower values of those measures. The four mountains were different regarding dispersion patterns and taxonomic groups, both for species and individuals. Onthophagus chevrolati dominated all four mountains with an overall relative abundance of 63%. CS was not related to distance among mountains, but when O. chevrolati was excluded from the analysis, CS values based on species abundance decreased with increasing distance. Speciation, dispersion, and environmental instability are suggested as the main drivers of high mountain diversity patterns, acting together at different spatial and temporal scales. Three species new to science were collected (>10% of all species sampled). These discoveries may indicate that speciation rate is high among these volcanoes-a hypothesis that is also supported by the elevated number of collected species with a restricted montane distribution. Dispersion is an important factor in driving species composition, although naturally limited between high mountains; horizontal colonization events at different time scales may best explain the observed species composition in the TMVB, complemented by vertical colonization events to a lesser extent. Environmental instability may be the main factor causing the high variability of diversity and abundance patterns found during sampling. Together, we interpret these results as indicating that species richness and composition in the high mountains of the TMVB may be driven by biogeographical history while variability in diversity is determined by ecological factors. We argue that current conservation strategies do not focus sufficiently on protecting high mountain fauna, and that there is a need for developing and applying new conservation concepts that take into account the high spatial and temporal variability of this system.

Co1 DNA supports conspecificity of Geomyphiluspierai and G.barrerai (Coleoptera, Scarabaeidae, Aphodiinae) and is a good marker for their phylogeographic investigation in Mexican mountains.

Members of Geomyphilus are associated with rodent burrows, such as pocket gophers and prairie dogs. In Mexico, they are found in the mountains of the Mexican Volcanic Belt and in Sierra Madre Oriental. Our study aims to initiate the exploration of the dispersal modes of Geomyphiluspierai and Geomyphilusbarrerai from burrows of pocket gophers. In order to estimate the dispersal scale of the beetles, the utility of mitochondrial and nuclear molecular markers for studying the phylogeographic structure of this complex of species (Geomyphiluspierai and Geomyphilusbarrerai) was tested from 49 beetle individuals. High intraspecific and intra-mountain nucleotidic diversity was captured from this sample using Co1 mitochondrial sequences, whilst the ITS2 nuclear ribosomal sequence did not allow observing informative variation. Mitochondrial phylogenetic analysis revealed that the specific delineation between the two species under study was doubtful. In this preliminary study, Co1 was shown to be a good marker for elucidating dispersal routes of the burrowing rodent-associated beetles.