The idiosomal chaetotaxy of astigmatid mites

Abstract

With 2 plates and 12 figures in the text) Within the Astigmata, setal homologies with the general chaetotaxic systems developed for acariform mites by F. Grandjean have never been convincingly established. This study deals with all body regions, exclusive of legs and gnathosoma, mostly utilizing as models astigrnatid species from three different families. Six hypotheses which attempt to explain the ontogeny of segments, setae and cupules in the caudal bend region are compared using three-dimensional views obtained by scanning electron microscopy. The hypotheses are evaluated by in-group comparisons testing their consistency with presumed segmental boundaries, and by out-group comparisons with oribatid mites. The strongest, most parsimonious hypothesis suggests that larval astigmatid mites possess segment F, but not its setae, and the two pairs posterior to segment Fare hl and h2, whilst the five setae added in the protonymph are h,, f2 and psi-3. Six pairs of structures on the deutonymphal anal plate are identified as modified setae, and evidence supporting their homologies with setae of other instars is discussed for the first time. A comparison of the principal chaetotaxic systems used for the dorsal and anal regions of the Astigmata is presented. Application of Grandjean's setal signatures to these regions, as well as to the coxisternal and genital regions, is discussed and illustrated by examples.

The genus Nanopterodectes Mironov, 2009 (Acari, Proctophyllodidae), with descriptions of three new species from antbirds (Passeriformes: Thamnophilidae) in Brazil

“…The chaetotaxy of the idiosoma and legs follows Griffiths et al (1990) and Atyeo & Gaud (1966), respectively. Host common and scientific names are according to Dickinson (2003 So far the genus is restricted to passerines of the family Thamnophilidae, and currently includes the type-species and three new species described below.…”

A new feather mite species of the subfamily Analginae (Acari, Astigmata, Analgidae) from the Savi’s warbler Locustella luscinoides (Aves, Passeriformes) in South Dobrudzha, Bulgaria

“…The idiosomal chaetotaxy follows Griffiths et al (1990) and that of the legs follows Atyeo and Gaud (1966 urements are in micrometers. Light microscopy photographs were used in order to determine all the details on the pictures.…”

Sarraceniopus nipponensis sp. nov. and S. hughesi (Astigmata, Histiostomatidae) from Sarraceniaceous Pitchers Bred in Japan

“…In this paper, nomenclature for idiosomal and leg setae followed Griffiths et al (1990) and Grandjean (1939), respectively. The measurements of more than 117 morphological characters in males, 61 in deutonymphs, as well as an RLI index (ratio of length or distance of structure to idiosomal length, Kurosa, 2002) were examined in this study (Appendix).…”