Idiosomal Setae Research Articles

Chenophila nanseni sp. n. (Acari: Syringophilidae) parasitising the barnacle goose in Svalbard

Abstract A new species, Chenophila nanseni sp. n., collected from covert quills of the barnacle goose Branta leucopsis (Anseriformes: Anatidae) in Svalbard (Spitsbergen) is described and female polymorphism is recorded in this species. In syringophilids this phenomenon was known only for representatives of the genus Stibarokris. The new species differs from the similar Ch. platyrhynchos by following features: in females of Ch. nanseni the anterior margin of the propodonotal shield is flat (vs. concave in Ch. platyrhynchos) and the lengths of idiosomal setae si, f2 and ag3 in Ch. nanseni are distinctly shorter than in Ch. plathyrynchos.

The Lasioseius phytoseioides species group (Acari: Blattisociidae): new characterisation, description of a new species, complementary notes on seven described species and a taxonomic key for the group.

The Lasioseius phytoseioides species group was first characterised over 50 years ago. Two species of this group, Lasioseius chaudhrii (Wu & Wang) and Lasioseius parberlesei Bhattacharyya, have been considered potentially effective as biological control agents of pest mites of the family Tarsonemidae on rice (Oryza sativa L.) in Asia. A new characterisation of the species group is presented, taking into account a new species here described, Lasioseius piracicabensis Moraes & Pérez-Madruga n. sp., as well as other species mostly described since the first characterisation of the group. The main characteristics of the included species are the reduced number of dorsal idiosomal setae, including the absence of j1 and z1; antiaxial surface of fixed cheliceral digit with a subterminal pointed process; and males with broad lateral expansion of the peritrematic shield in the region between coxae II-III, bearing a pore and a lyrifissure. Complementary notes are presented for Lasioseius annandalei Bhattacharyya & Bhattacharyya, Lasioseius chaudhrii (Wu & Wang), Lasioseius parberlesei Bhattacharyya, L. phytoseioides Chant, Lasioseius punjabensis Bhattacharyya & Sanyal, Lasioseius terrestris Menon & Ghai and Lasioseius youcefi Athias-Henriot. New synonymies are proposed and possible misidentifications in the literature are discussed. A dichotomous key is presented to help the identification of the species of the group, and the distribution of the species is summarised.

A new feather mite of the genus Dolichodectes (Astigmata: Proctophyllodidae) from Hippolais polyglotta (Passeriformes: Acrocephalidae) in Spain.

A new feather mite species, Dolichodectes hispanicus sp. n. (Astigmata: Proctophyllodidae), is described from the Melodious Warbler Hippolais polyglotta (Vieillot) (Passeriformes: Acrocephalidae) in Spain. The new species is closest to the type species of the genus, D. edwardsi (Trouessart, 1885) from the Grear Reed-Warbler Acrocephalus arundinaceus (Linnaeus) (Acrocephalidae). Adults of D. hispanicus differ from those of D. edwardsi by dimensional characteristics, in particular, by having shorter aedeagus that does not extend to the anal suckers in males and shorter hysteronotal shield in females. Tritonymphs of D. hispanicus are much more distinctive and differ from those of D. edwardsi by having the prodorsal shield covering all the prodorsum, the hysteronotal shield occupying about three quarters of the hysterosoma, and idiosomal setae h3 being filiform. The morphological description of the new species is augmented by sequence data from the mitochondrial cytochrome c oxidase subunit I gene fragment (COI).

A new species of Orthadenella (Athias-Henriot) (Acari: Mesostigmata: Melicharidae) from Iran with comments on O. lawrencei (Evans)

A new melicharid mite belonging to the genus Orthadenella Athias-Henriot (1973), namely Orthadenella multipilisaccula sp. nov., is described. It was collected from forest soil in northern Iran. By having different shapes of spermathecal apparatus and tectum, and different sizes of legs and some dorsal idiosomal setae, it can be distinguished from Orthadenella lawrencei (Evans, 1958), a closely related species. For a thorough comparison, voucher specimens of O. lawrencei were examined by material loaned from Finnish Museum of Natural History, Helsinki and Museum für Naturkunde, Berlin.http://zoobank.org/urn:lsid:zoobank.org:pub:8772EFAC-3E47-43F0-A1E8-663C43C52F46

Description of all the stages of Ixodes inopinatus n. sp. (Acari: Ixodidae)

All of the parasitic stages of Ixodes inopinatus n. sp. are described from specimens collected by flagging and on lizards and foxes. The new species replaces I. ricinus in dry areas of the Mediterranean region in Spain, Portugal, Morocco, Algeria and Tunisia. It has also been collected in areas of western Germany in sympatry with I. ricinus, far of its known distribution range and on an unusual host. The females of the new species can be separated from I. ricinus by the relative dimensions and punctations of the scutum, the length of the idiosomal setae, the size of the auriculae, and the aspect of the porose areas. Nymphs of I. inopinatus can be easily separated from I. ricinus by a combination of scutal dimensions, the relative size of scutal and alloscutal setae, and the relative size of the spurs on coxa I. The larvae of the new species have a broader than long scutum and unusually long Md1 to Md3 idiosomal setae. The new species is allopatric with I. ricinus in Spain and Portugal. It is hypothesized that it has been historically overlooked and reported as I. ricinus at least in northern Africa, southern Spain and parts of south-western Portugal. The existence of a new species in the I. ricinus complex makes necessary the critical assessment of its complete distribution, its abiotic preferences and seasonal activity, as well as its hosts and implications for the transmission of pathogens.

Idiosomal setae in the family Phytoseiidae (Acari: Mesostigmata): variation, geographical distribution and taxonomic considerations

Phytoseiidae classification is based on idiosoma chaetotaxy and the assumed evolutionary process is seta suppression. This article aims to determine how depilation could have taken place depending on seta position, subfamily and region. For this, the occurrence of 21 variable setae on dorsal and ventral shields was determined for 1996 species in seven biogeographical regions. The occurrence of eight rare setae assumed to be past relics and 11 rarely absent setae (assumed to be undergoing a loss process) was analysed. The subfamily Phytoseiinae has ‘lost’ the highest number of primitive setae, the subfamily Amblyseiinae has ‘retained’ the highest number and Typhlodrominae has an intermediate position, except for the seta z6. The subfamily Phytoseiinae shows the highest number of setae undergoing a loss process, whereas the subfamily Typhlodrominae has lost these setae in 674 species and subfamily Amblyseiinae in 415 species, making this latter subfamily that with the most retained dorsal setae. According to spatial seta occurrence, it could be hypothesized that Amblyseiinae originated from South Gondwana, Typhlodrominae from the Euro-America region (Laurasia zone) and Phytoseiinae from the Ethiopian area. The presently admitted classification of Phytoseiidae is discussed with regard to the occurrence of rarely present setae (assumed to have been lost in high frequency).

Scanning electron microscopy and morphometrics of nymph and larva of the tick Hyalomma rufipes Koch, 1844 (Acari: Ixodidae).

The genus Hyalomma comprises the most ixodid tick species that parasitize camels in Egypt. Although the immature stages of tick species play an important role in distribution of ticks and tick-borne diseases, the identification depends mainly on the adult stage. Therefore, this study tries to identify the specific characteristics of both nymph and larva of Hyalomma rufipes Koch, 1844 using scanning electron microscopy and morphometric analysis in order to differentiate them easily from those of other Hyalomma spp. described before in Egypt. Results showed that the nymph and larva of H. rufipes can be easily identified from those of H. excavatum Koch, 1844, H. dromedarii Koch, 1844 and H. impressum Koch, 1844 but they are strongly close to H. marginatum Koch, 1844. The nymph of H. rufipes can be distinguished from H. marginatum by the number and distribution of dorsal and ventral idiosomal setae and the distribution of sternal setae. All morphological characteristics of H. rufipes larva resemble those of H. marginatum larva. The measurements of nymph and larva structures of H. rufipes are significantly lower than those of H. marginatum.

Neotrombicula inopinata (Acari: Trombiculidae) - a possible causative agent of trombiculiasis in Europe.

BackgroundFor over a decade, the presence of trombiculid mites in some mountain areas of La Rioja (Northern Spain) and their association with seasonal human dermatitis have been recognized. This work aimed to establish the species identity of the agent causing trombiculiasis in the study area.MethodsTrombiculid larvae (chigger mites) were collected from vegetation in the Sierra Cebollera Natural Park and in Sierra La Hez during an outbreak of human trombiculiasis in 2010. Three specimens collected from a bird were also examined. Identification was made using morphological and morphometric traits based on the most recent taxonomic sources. A comparison of those mites with specimens of the same species collected throughout Europe was performed by means of cluster analysis with multiscale bootstrap resampling and calculation of approximately unbiased p-values.ResultsAll collected mites were identified as Neotrombicula inopinata (Oudemans, 1909). Therefore, this species is the most likely causative agent of trombiculiasis in Spain, not Neotrombicula autumnalis (Shaw, 1790), as it was generally assumed. No chigger was identified as N. autumnalis in the study area. Neotrombicula inopinata clearly differs from N. autumnalis in the presence of eight or more setae in the 1st and 2nd rows of dorsal idiosomal setae vs. six setae in N. autumnalis. Comparison of N. inopinata samples from different locations shows significant geographic variability in morphometric traits. Samples from Western and Eastern Europe and the Caucasus formed three separate clusters.ConclusionSince the taxonomical basis of many studies concerning N. autumnalis as a causative agent of trombiculiasis is insufficient, it is highly possible that N. inopinata may be hiding behind the common name of “harvest bug” in Europe, together with N. autumnalis.

A new genus and two new species of chigger mites (Acari: Trombiculidae) from the Laotian rock-rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins (Rodentia: Diatomyidae)

A new chigger mite genus Laotrombicula n. g. and two new species, Laotrombicula khunboromi n. sp. (type-species) and L. fangumi n. sp., are described from the Laotian rock-rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins (Rodentia: Diatomyidae). The new genus is most similar to Trombiculindus Radford, 1948 and Leptotrombidium Nagayo, Miyagawa, Mitamura & Imamura, 1916 and differs from these genera by having the scutum of subhexagonal or semicircular shape vs widely rectangular; pinnatifid dorsocentral idiosomal setae vs foliaceous in Trombiculindus and unexpanded in Leptotrombidium; and by the presence of serrated longitudinal crests in the middle part of scutum.

A new sand mite of Schoengastia (Acari: Trombiculidae) from the soil under camel’s thorn in Iran

A new species of the sand-mite or chigger Schoengastia Oudemans, 1910 collected from the soil under camel’s thorn ( Alhagi maurorum Medik) in Iran is described. The diagnosis of the new species is in conformity with the subgenus Priomesochela Vercammen-Grandjean et Langston, 1976, the specific characters are drip-dropping shaped sensilla, shortest scutal setae and least number in idiosomal setae in the subgenus.

A New Species of the Genus Eustigmaeus (Berlese) (Acari: Stigmaeidae) from Western Iran

ABSTRACT A new mite species, Eustigmaeus dogani, is described and figured based on holotype female collected from alfalfa soil Medicago sativa L., Sanandaj, Kurdistan province, and one paratype collected from grassy soil, Rijab, Kermanshah province, Iran. The dorsal idiosomal setae of the new species clearly thick and with few serrations, and coxisternal shields distinctly reticulated. A key to all known Iranian species of the genus is given.

Proposed nomenclature for idiosomal setae in otopheidomenid mites (Acari: Otopheidomenidae) known from sphingid moths (Lepidoptera: Sphingidae)

ABSTRACT Seven species of otopheidomenid mites (Acari: Otopheidomenidae), all described by Prasad in the genus Otopheidomenis and now belonging to the genus Prasadiseius Wainstein (P. achlora, P. aporodes, P. cocytes, P. donahuei, P. indicus, P. kayosiekeri, and P. pholusis) are known to occur on sphingid or hawk moths (Lepidoptera: Sphingidae). These species are redescribed following the work of Chant and Yoshida-Shaul (1992) on the nomenclature of the idiosomal setae of phytoseiid mites, the sister group of the Otopheidomenidae, and applied for the naming of the idiosomal setae of species of the genus Prasadiseius (Otopheidomenidae). A discussion of which setae are fixed and variable and a key for the identification of the known species are also provided.

Scanning electron microscopy studies on Prasadiseius kayosiekeri (Prasad, 1970) (Acari: Mesostigmata: Otopheidomenidae): idiosoma

ABSTRACT A scanning electron microscopic study of idiosomal structures of Prasadiseius kayosiekeri (Prasad, 1970) (Acari: Otopheidomenidae) provides details of the dorsal idiosomal, sternal, genital and anal shield. The setae are identified according to the system proposed by Prasad [Prasad, V. 2011. Proposed nomenclature for idiosomal setae in otopheidomenid mites (Acari: Otopheidomenidae) known from sphingid moths (Lepidoptera: Sphingidae). Internat. J. Acarol. 37(1):11–30]. These studies complement previous microscopy studies reported by Prasad [Prasad, V. 1970b. Two new species of Otopheidomenis (Acarina: Phytoseiidae) ectoparasitic on sphingid moths with a note on Noctuiseius. Can. Entomol. 102(10): 1209–1215] and augment with details in the electron micrographs.

Five new species of predaceous cheyletid mites (Acari: Prostigmata: Cheyletidae)

Five new species and 1 new genus of predaceous cheyletid mites (Acari: Cheyletidae) are described. Oconnoricheylus gen. nov. (type species O. speciosus sp. nov.) differs from Alliea in both sexes by the presence of 4 setae on tibia II and in males by the palpal claws possessing elongated projections, an apically slightly serrate eupathidium ul’ and comb-like eupathidia acm and sul. Oconnoricheylus speciosus sp. nov. (from oranges, USA) differs from O. chimaera (Bochkov & Ochoa) comb. nov. (transferred from Alliea) by the presence of 2 filiform setae on tibia II, the distinct ornamentation of the dorsal shields, and by the absence of angles on the leg tarsal claws. Cheletomimus crowei sp. nov. (from avocado, New Zealand) differs from C. filipina Corpuz-Raros and C. notelaeae Gerson by smooth filiform setae dF of the palpal femur, smooth idiosomal setae c2, the presence of setae ps3, setae se located off the propodonotal plate, bases of setae e1 located almost at the same level with bases of e2, and by the propodonotal shield in the shape of an inverted trapezium. Chelacheles thomasi sp. nov. (from oranges, Australia) differs from C. stigmaeoides Barilo by the absence of setae c4, short and serrate rod-like setae c2 (about 40 long), and by the presence of 2 setae on femur III. Chelacheles indra sp. nov. (from beetles Sinoxylon crassum, India) differs from C. baiwanganae Corpuz-Raros by the absence of setae f1, by setae h1 being slightly shorter than other hysteronotal setae. Bak indonesiensis sp. nov. (from undetermined beetle, Indonesia) differs from B. elongatus Patxot & Goff and B. faini Corpuz-Raros by the presence of 1 seta (l’) on genu III, the slightly clavate dorsal setae of the idiosoma, setae e1 being subequal in shape and sizes to their anterior hysteronotal setae, and by the presence of a pair of distinct lateral teeth on the rostral shield.

Genus Acalvolia (Acari: Winterschmidtiidae), with the description of a new species from the USA

The definition of the mite genus Acalvolia is revised. A new species, Acalvolia americana, with conidia of Cladosporium sp. in its gut, intercepted on orange from the United States is described. Currently the genus consists of only one species, and the new species is distinguished from that species by having smooth supracoxal setae, longer setae sci (ratio sce: sci = 2.5–2.7), and longer dorsal idiosomal setae c1, d1 and e1 (reaching to or overlapping the bases of setae in the next row).

A new species of the genus Allothrombium (Acari: Trombidiidae) from Montenegro

Allothrombium clavatum sp. n. with reduced inner claw of tarus III, one seta on coxa II, clavate dorsal idiosomal setae and 3-lobed posterior margin of scutum, collected as ectoparasite of an undetermined aphid, is described and illustrated from the central part of Montenegro (Balkan Peninsula). A key to world species of Allothrombium (larva) is presented.

Afroproterothrix n. gen. of the feather mite subfamily Pterodectinae (Astigmata: Proctophyllodidae) from passerines (Aves: Passeriformes) in Africa

ABSTRACT A new feather mite genus and species Afroproterothrix marginata n. gen., n. sp. is described from the western black-headed oriole, Oriolus brachyrhynchus Swainson, 1837 (Passeriformes: Oriolidae), in Cameroon. The new genus belongs to the Proterothrix generic group and is most similar to the genus Nanopterodectes Mironov, 2009 by the loss of idiosomal setae d2, f2 and by having solenidia s1 and ?3 on legs I subequal in length. The genus Afroproterothrix differs from Nanopterodectes by the following combination of features: in both sexes, idiosomal setae c1 and trochanteral setae sRIII are absent, idiosomal setae e2 are present, the humeral shields on dorsal surface of the hysterosoma are not developed; in males, the opisthosomal lobes are poorly developed, the branches of the genital arch are well developed; in females, the hysteronotal shield is not divided into anterior and lobar parts. Brief comments on the systematics of the subfamily Pterodectinae are given.

Nidocheyletus kennedyae n. gen, n. sp. (Prostigmata: Cheyletidae) from nests of passerine birds in Michigan, USA

ABSTRACT The external morphology of all postembryonic instars of a new cheyletid mite, Nidocheyletus kennedyae n. gen., n. sp., inhabiting nests of passerine birds in Michigan is described and illustrated in detail. This new genus belongs to the Cheletomimus generic group of the tribe Cheyletini. It differs from the genus Cheletomimus by the moderately developed apical knobs of the tarsi, the absence of the nipple-like protrusion bearing solenidion ω1 and guard seta on tarsus I, non-granulated cuticle of the idiosoma and gnathosoma, hair-like setae c2, presence of solenidia on tarsi III–IV in males, and microchaetae ft of tarsi I in immature stages. Nidocheyletus also differs from Tutacheyla, the second genus of the group, by the arch-like peritremes, palpal claws with teeth only basally, presence of median idiosomal setae (c1, c3, d1, e1, and f1) and setae h3, presence of leg setae l′TrIII, vFIII, and l′GIV, and by the absence of setae l′′TiIV.

A New Genus and Two New Species of Pygmephoridae (Acari: Heterostigmata) Phoretic on Lasioglossum (Hymenoptera: Halictidae) in Japan

A new genus and two new species of pygmephorid mites belonging to the subfamily Neopygmephorinae are described from Japan under the names Insensilla lasioglossi and I. duplicis. They are known only from the adult females found attached to the halictid bees, Lasioglossum apristum (Vachal) and L. duplex (Dalla Torre), respectively. The new genus is readily distinguished from all the known genera of the family by that the prodorsum entirely lacks the so-called sensillum (=seta sc1), but that the bothridium is retained though fairly reduced in size. I. lasioglossi, the type species, is easily discriminated from I. duplicis, the other member of the genus, by possession of much stronger barbs on the apices of most dorsal idiosomal setae, obviously shorter coxal setae, and so forth.

Dendrochaetidae, a new family of mites (Acari: Prostigmata), with descriptions of a new genus and species from South Africa

A new family, Dendrochaetidae, and genus, Dendrodus, collected from soil samples from South Africa are diagnosed and described. An identification key separating the families of the superfamily Eupodoidea is presented. A new species, Dendrodus acarus is described and illustrated. The diagnostic morphological features are illustrated to be a combination of the type of setae of the idiosoma and appendages; palpal segmentation; the number and type of setae, rhagidial solenidia and erect solenidia of the palptarsus; presence and distribution of erect solenidia of leg segments; coxal chaetome; differences in the complement of cheliceral setae (cha and chb) and adoral setae (or1 and or2) and the number and distribution of dorsal idiosomal setae. The most essential diagnostic features of the new taxon are comparatively discussed for members of Penthaleidae and Pentapalpidae, selected species of Penthalodidae, Eupodidae and Rhagidiidae. Reference to similar features displayed by other prostigmatic mites (not representatives of Eupodoidea) is made.