Leg Chaetotaxy Research Articles

A new species group and five new species of the genus Pavania (Acari: Dolichocybidae) associated with insects, with notes on leg chaetotaxy and the distribution of genera

A new species group and five new species of mites of the genus Pavania Lombardini, 1949 belonging to the family Doli- chocybidae (Acari: Heterostigmata) are described from Iran. Pavania gymnopleuri Hajiqanbar & Khaustov sp. n., P. sabzevarensis Hajiqanbar & Khaustov sp. n. and P. onthophagi Hajiqanbar & Khaustov sp. n., represent a new gymnopleuri species group. Two new species are also described in the fusiformis group: P. kamalii Hajiqanbar & Khaustov sp. n. and P. elongata Hajiqanbar & Khaustov sp. n. All new species are associated with scarabaeid and carabid beetles (Coleoptera: Scarabaeidae, Carabidae). This is the first record of the family Dolichocybidae from Iran. The leg setation and geographic distribution of all genera of this family are discussed and keys to genera and species of the genus Pavania are provided.

<strong>Mites and millipedes: a new <em>Neomegistus</em> (Acari: Mesostigmata:</strong> <strong>Paramegistidae) from Australia</strong>

Neomegistus remus sp. nov. (Acari: Mesostigmata: Paramegistidae) is described from two female specimens collected from Lord’s Table Mountain in Queensland on the millipede Proporobolus sp. (Spirobolida: Rhinocricidae). This new mite species is the second for the genus, which was previously known from millipedes in South Africa and Madagascar. We also rediagnose Neomegistus and provide a new diagnosis for Ophiomegistus, whose members share many characters in common with Neomegistus. The leg chaetotaxy for the Paramegistidae is also reviewed.

A new genus and species of mites of the family Caraboacaridae (Acari: Heterostigmata) associated with carabid beetles (Coleoptera: Carabidae) from Iran

A new genus and species of mites of the family Caraboacaridae (Acari: Heterostigmata), Minicaraboacarus quadridiscalis Hajiqanbar and Khaustov n. gen., n. sp. associated with Cymbionotum semelederi (Chaudoir, 1851) (Coleoptera: Carabidae) is described from Iran. The leg chaetotaxy and solenidiotaxy of mites of the family Caraboacaridae are discussed.

A new species of Hexabdella (Acari: Bdellidae) from Brazil

A new species of the genus Hexabdella Van der Schyff, Theron & Ueckermann, Hexabdella cinquaginta sp.n. is herein described, representing the second species of the family Bdellidae from the neotropical region. It can be distinguished from H. singula by its lobed striae on lateral margins of hysterosoma and by the leg chaetotaxy. A key to species of the genus is presented.

Re-evaluation of Australian and South American Unionicola Haldeman (Acari: Unionicolidae)

The genus Unionicola Haldeman in the family Unionicolidae is distributed worldwide, with more than half of the known species recorded as parasites of freshwater mussels (Mollusca: Bivalvia: Unionoida). Re-evaluation of the morphology and biogeography of the genus in Africa, Australia and South America extends our knowledge of host selection and host-specificity among Unionicola. New host and geographic records for Unionicola (Kovietsatax) walkeri Viets are Velesunio angasi in Western Australia. The subgenus Australatax Vidrine is re-evaluated. A new subgenus, Hyricola n. subgen., is erected for Australian members of the subgenus Australatax sensu lato. Discrete differences in leg chaetotaxy, pedipalp morphology, and female genital field chaetotaxy clearly separate the newly redefined Australatax from Hyricola. These changes provide an opportunity to re-evaluate all the gill mites in the Southern Hemisphere.

A new species of Paradiplogynium (Acari: Diplogyniidae) from Titanolabis colossea (Dohrn) (Dermaptera: Anisolabididae), Australia's largest earwig

Paradiplogynium nahmani sp. n. is described from three specimens taken from the Colossus Earwig Titanolabis colossea (Dohrn) in Australia. This new species differs from its only congeneric species, Paradiplogynium panesthia Womersley, by its larger body size and presence of one pair of latigynial setae (instead of two pairs). Setal designations are given for leg setae. Leg chaetotaxy for this species is compared with previous data and is generally, but not entirely, consistent with other Diplogyniidae.

Unionicola (Iridinicola) botswaniana n. subgen., n. sp. (Acari: Unionicolidae) from freshwater mussels in Botswana

Unionicola (Iridinicola) botswaniana n. subgen., n. sp. (Hydrachnida: Unionicolidae) is described from freshwater mussels, Mutela zambesiensis and Aspatharia pfeifferiana, from Okavango River, Botswana, Africa. The new species is a unique mite with distinctive female genital field anatomy and leg chaetotaxy. This new mite extends our understanding of the morphology and biogeography of the genus in Africa. It further extends our knowledge of host selection and host-specificity among African Unionicola.

Recent advances in Collembola systematics

Summary The study reviews recent advances in Collembola systematics. First, the knowledge on Collembola biodiversity is analysed in a historical perspective. Since a century, there is a fast and regular pace in species descriptions, with no sign of slow down. Second, new approaches and new tools, which are re-shaping current Collembola systematics are listed and summarised. They include the development of ontogenetic approaches, attempts to homologise morpho-chaetotaxic patterns across taxa and to elaborate unified nomenclature, the irruption of molecular tools, and the generalisation of cladistic approaches to address evolutionary problems. Important new characters have been discovered. Antennal chaetotaxy, leg chaetotaxy, dorsal chaetotaxy, S-chaetae patterns on tergites, and mouthparts have gained a prominent place in current Collembola taxonomy because of their high discriminating power. On this background and from extensive biological surveys in new areas of the world, significant results were obtained during the last three decades in terms of taxonomical discoveries, sibling species discrimination and species clusters, changes in taxonomical hierarchy, evolutionary history of the order and phylogeny of several groups. Remaining and newly emerging problems are discussed.

Evolutionary Trends of External Morphology in the Marine Mite Genus Rhombognathides (Acari: Halacaridae: Rhombognathinae)

A morphology-based phylogenetic analysis of the eight species of Rhombognathides (Acari: Halacaridae) demonstrated some evolutionary tendencies of character transformation. In the course of the evolution of Rhombognathides, idiosomal plates increased in size or fused. Simple filiform setae transformed into spiniform or bipectinate setae. The number of tarsal claws, the length of median claw and leg chaetotaxy of telofemora and tibiae were reduced. The fusion or expansion of dorsal plates, transformation from filiform to other setal forms, and reduction of leg setae would have recurrently occurred in halacarid evolution. The claw structure most likely reflects adaptation to specific habitat.

Some Unusual Neotropical Neocoelidiinae with a Redefinition of the Subfamily (Hemiptera: Membracoidea: Cicadellidae)

Diagnostic characters for the New World leafhopper subfamily Neocoelidiinae are reviewed. Krocodona Kramer (with new synonym Krocobella Kramer), Krocozzota Kramer, and the fossil genus Krocarites Dietrich and Vega, previously placed in Nirvaninae based on their depressed, strongly produced heads, are transferred to Neocoelidiinae (new placements) based on characters of the head, wing venation, leg chaetotaxy, and male genitalia. The related neocoelidiine leafhopper genera Retrolidia, new genus, based on three new species, and Krocolidia, new genus, based on two new species, all from South America; four new South American species of Krocodona; and a new species of Krocozzota (including the first known male of the genus) are described and illustrated. Keys to Krocodona and Retrolidia species and a checklist of neocoelidiine genera are provided.

Morphological Observations on Brevipalpus phoenicis (Acari: Tenuipalpidae) Including Comparisons with B. californicus and B. obovatus

The genus Brevipalpus has over 300 species worldwide. The three most important agricultural pest species in the genus, Brevipalpus californicus (Banks), B. obovatus Donnadieu, and B. phoenicis (Geijskes), have been consistently confused and misidentified for more than 50 years. The present study provides a discussion of the characters and character states used to separate these mites. Low-temperature scanning electron microscopy and traditional light microscopy techniques were used to illustrate the subtle morphological differences between these three species. Morphology of the dorsal propodosoma, opisthosoma, and leg chaetotaxy of all three species was examined and compared. The number of dorsal setae, the number of solenidia (omega) on tarsus II, and dorsal cuticular patterns were the most important characters in the identification of Brevipalpus species. B. phoenicis is similar to B. californicus in having two omega on tarsus leg II and different from B. obovatus which has only one omega on tarsus leg II and similar to B. obovatus in having only one pair of F setae (f3), but differing from B. californicus which has two pairs of F setae (f2-3). The dorsal opisthosomal and propodisomal cuticular patterns frequently used to distinguish between these three species are useful but one must be aware that age, feeding, and mounting techniques can affect the appearance of these characters.

The genus <i>Eupodes</i> Koch, 1835 (Acari: Prostigmata: Eupodidae) from southern African soil and vegetation. Part 1. Characterisation of the genus, designation of the type species and descriptions of three new species

Based on a study of the Eupodoidea of southern Africa, the genus Eupodes is redefined, with the incorporation of additional features, to distinguish it from other genera. E. striola Koch, 1835 is conceived as type species for the genus. Three new species, E. lutatus, E. indentatus and E. hamatus are described and figured. Special attention is contributed to the shape and position of dorsal idiosomal setae, chaetotaxy of the palp, leg chaetotaxy and solenidiotaxy. Both species are compared with their nearest congeners.

Neottialges neopelagicus new species (Acari:Hypoderatidae) from the pelagic cormorant (Aves:Phalacrocoracidae:Pelecaniformes).

A new species of hypoderatid deutonymph is described from the subcutaneous adipose tissues of the pelagic cormorant, Phalacrocorax pelagicus Pallas, from Alaska. Neotialges neopelagicus n. sp. is similar to the 3 other Neottialges spp. from cormorants. N. neopelagicus closely resembles N. tasmaniensis Fain & Domrow except the genital apodeme is incomplete in the latter, but the sclerotized T-shaped extremities are connected by a thin line of sclerotization to form a complete central apodeme in N. neopelagicus. There also are minor differences in leg chaetotaxy of these 2 species. The genital apodeme is heavily sclerotized throughout its length in N. evanis Fain and N. pelagicus OConnor. In both these species, seta d4 is long and resembles other middorsal idiosomal setae, whereas it is short and hairlike in N. tasmaniensis and N. neopelagicus. In N. pelagicus terminal seta as on tarsus IV is smooth; it is serrated in the other three species. The single pelagic cormorant we found infected with N. neopelagicus shared this host with N. pelagicus, emphasizing the possibility of coexistence of 2 very similar species of hypoderatids in the same host individual.

Systematic revision and phylogeny of the Palaearctic species of the genus Achalcus Loew (Diptera: Dolichopodidae) with the description of four new species

Abstract. The Palaearctic species of the genus Achalcus (Diptera: Dolichopodidae) are revised. Besides redescriptions of A.cinereus, A.fiavicollis, A.melanotrichus, A.thalhammeri and A.vaillanti, four species are described as new: A.bimaculatus, A.britannicus, A.nigropunctatus Pollet & Brunhes and A.phragmitidis. Keys to males and females of all Palaearctic species of the genus are given. Both morphologically and ecologically, A.melanotrichus is clearly distinct from all other species and seems to demonstrate the most primitive characters, especially in the thoracic and leg chaetotaxy. Epandrial setae and the epandrial lobe are clearly separated in the hypopygium of this species, whereas the former seem to be incorporated in the epandrial lobe in all other Palaearctic species. Seven out of 9 species show pale abdominal stemites and the presence or absence of the sutural bristle proves to be of special diagnostic value within this group. Furthermore, the reduced size of the anterodorsal bristles on the hind femur is considered a significant synapomorphy in four species. Finally, the investigation of Nearctic, Neotropic and Australasian Achalcus is considered relevant to confirm the polarity of a number of characters in this genus.

Redescription of Alcedinectes alcyon (Acari:Hypoderatidae) from the belted kingfisher (Aves:Coraciiformes; Alcedinidae).

Alcedinectes alcyon (Boyd) is redescribed based on specimens collected from its belted kingfisher, Megaceryle alcyon (L.), type host in Florida. This species differs from A. cerylei Fain by the chaetotaxy of tarsus III. A. alcyon has a long stout apical seta that tapers to a curved tip resembling that seen on tarsus III of the genus Tytodectes (Ispidectes) Fain. The equivalent seta in A. cerylei is a stout spine. There are other minor differences between these species in the pattern of idiosomal sclerotization and leg chaetotaxy. The chaetotaxy and solenidiotaxy of legs I and II in Alcedinectes closely resemble that of Amazonectes psittaci Fain & Vercammen-Grandjean from parrots (Psittaciformes), whereas the morphology and chaetotaxy of the idiosoma resemble that of Tytonectes (Ispidectes) spp. which also occurs in kingfishers (Coraciiformes). The long stout seta that tapers to a curved tip on tarsus III in A. alcyon also links the genus Alcedinectes with Tytodectes (Ispidectes).

A New Species of the Genus Anomalohalacarus(Acari: Halacaridae) from Japan with Notes on Taxonomic Characters.

A new species in the genus Anomalohalacarus Newell is described under the name of Anomalohalacarus biformis. sp. on the basis of specimens from a subtidal sandy sediment in Tottori Prefecture, western Japan. A. biformis is closely related to Anomalohalacarus macellus Bartsch, 1993, but differs from this species in the structure of the genitoanal region in the female and in the leg chaetotaxy. This is the first record of the genus Anomalohalacarus from the Pacific region. Morphological features of genitoanal and posterior dorsal plates are discussed on the basis of the new species and so far known species.The character of the posterior genital platelet is thought to be more important taxonomically than that of the genital groove in the female. According to the criterion of ontogenetic character precedence and the rule of out-group comparison, the divided condition of the posterior dorsal plate observed in Anomalohalacarus is considered to be an apomorphic character state.

Redescription of Picidectes chapini and synonymy of Picidectes and Toucanectes (Acari: Hypoderatidae) from piciform birds.

A redescription of Picidectes chapini (Spurlock & Emlen) Fain is presented with particular attention to the underscribed details of idiosomal and leg chaetotaxy, solenidiotaxy, and size variation in the range of measured characters of the species. This is the second record of P. chapini from the northern flicker Colaptes auratus (L.) in North America. Aside from the mediolateral constriction just posterior to epimera IV, the morphology, chaetotaxy, and solenidiotaxy of P. chapini are very similar to those of the two known species in the genus Toucanectes Fain described from a toucan and woodpecker (both Piciformes), respectively. Thus, the genus Toucanectes is recognized as a junior synonym of Picidectes. The genus Picidectes is redescribed to include P. chapini as the type species, and P. ramphastos Fain n. comb. and P. dryocopi Pence n. comb.

First record of an hypopus (Acari: Hypoderatidae) from a jaeger (Aves: Charadriiformes: Stercorariidae).

Thalassornectes (Alcidectes) aukletae, originally described from two species of auklets (Charadriiformes: Alcidae) from maritime eastern Russia, is reported from a third species of pelagic charadriiform (Stercorariidae), the pomarine jaeger, Stercorarius pomarinus (Temminck), from Florida. The specimens from the jaeger are slightly smaller, the genital apodeme is more heavily sclerotized, paired setae gm are twice as long and there are other minor variations in the idiosomal and leg chaetotaxy. These differences are not considered sufficient to warrant taxonomic separation at the species or subspecies level from the nominate species T. (A.) aukletae. The same hypopus occurring across different families of birds is unusual in the Hypoderatidae. The diversity in hosts from several orders of birds, low intensities of infection in the two species from Africa, low prevalences in alcids from Russia, and rarity of these hypoderatids in all surveyed hosts leads us to speculate that the true host affinities of species in the genus Thalassornectes are unknown. The alternative consideration is that these are simply uncommon species that are very host specific.

A New Species of the Genus Scaptognathus(Acari:Halacaridae) from Tasmania.

A new species of the genus Scaptognathus is described from the Bass Strait under the name of Scaptognathus bassianus sp. nov. The present new species is distinguished from the congeners by the unique leg chaetotaxy of bipectinate setae. Geographical distribution of the genus Scaptognathus is also given.

REDEFINITION OF MEGEREMAEUS (ACARI: MEGEREMAEIDAE) WITH DESCRIPTION OF NEW SPECIES, AND NYMPHS OF M. MONTANUS HIGGINS AND WOOLLEY

AbstractThe oribatid mite genus Megeremaeus is redefined, with the addition of information on leg chaetotaxy and immature instars. Three new species are described, Megeremaeus hylaius from northeastern North America, and M. keewatin and M. kootenai from northwestern North America. Descriptions of the former two species are based on adults and immatures, the latter species on adults only. Nymphs of M. montanus Higgins and Woolley are described. A key is given for the six known species in the genus.