New records of Xenanoetus species (Astigmata: Histiostomatidae) in Western Europe, and their association with pig carcasses

Medjedline Hani,M Alejandra Perotti,Marta I Saloña-Bordas

doi:10.1007/s11756-021-00997-2

Medjedline Hani, M Alejandra Perotti + Show 1 more

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https://doi.org/10.1007/s11756-021-00997-2

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Abstract

The genus Xenanoetus Mahunka, 1969, only described by the hypopial stage, is characterised by an enlarged gnathosoma, the presence of double claws in legs I, II and III in addition to remarkably broadened femur and genu of legs I and II, particularly visible in lateral view. Only five species from this genus have been described and they are all from the northern hemisphere. Hypopi are generally found as phoretic on Sphaeroceridae flies and Hydrophilidae beetles. Until present, hypopi of the species Xenanoetus grandiceps have only been reported in Mongolia, described by Mahunka in 1973. Xenanoetus grandiceps is characterised by the presence of a pair of arches pointing anteriorly in the posterior part of the gnathosoma. Here we report for the first time X. grandiceps in Spain, and for the second time X. vestigialis. Both species were found in association with carcass remains, as phoretic on lesser dung flies (Sphaeroceridae), which were collected in a mixed deciduous forest near the Atlantic coast. Additional new information on morphological characteristics of these Xenanoetus species, as well as habitat requirements and biology are presented in this report.

Highlights

Xenanoetus is a genus of Myanoetinae (Histiostomatidae, Sarcoptiformes), a subfamily of astigmatid mites, strictly associated with dung flies and beetles
Sphaeroceridae flies were attracted to pig carcasses on day 3 (Dip 51) and day 13 (Dip 20, Dip 32) after deceased; the carcasses were at the fresh stage for Dip 51 and advanced stage of decomposition for Dip 20 and Dip 32
Both mite species were found on Sphaeroceridae from the research conducted in Aiako Harria (Gipuzkoa, Spain)

Summary

Introduction

Xenanoetus is a genus of Myanoetinae (Histiostomatidae, Sarcoptiformes), a subfamily of astigmatid mites, strictly associated with dung flies and beetles. Histiostomatidae mites moult into a modified deutonymph known as hypopus, an adaptation to phoresy on flying insects for securing transportation to more favourable environmental conditions (Hughes 1976; Braig and Perotti 2009). Hypopi present structures adjusted to phoresy such as ventral suckers that are modified to enable their attachment to their carriers, frequently insects (Hughes 1976; Braig and Perotti 2009). The lack of knowledge on adult forms of many members of the Histiostomatidae has. This is the case of Xenanoetus hypopi, whose species have only been described based on the heteromorphic deutonymph. In Europe, only one species from Hungary has been described, which is X. vestigialis Mahunka, 1969

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