Ventral Shield Research Articles

Generic concept of the phytoseiids (Acari: Phytoseiidae) according to Athias-Henriot

The economic importance of the Phytoseiidae motivated many scientists to work on the systematics of this family. One of them was the French acarologist Claire Athias-Henriot. In her first work, she tackled the question of supraspecific groupings within this family from an evolutionistic point of view, and suggested a system for numbering dorsal shield setae, that could be applied to both hypotrichous and holotrichous forms. She also looked for other characters, such as the ratios of the distance between the insertions of some setae on dorsal and sternal shields, the presence of macrosetae on legs, and the length/width ratio of the ventrianal shield. Following Dosse (1957; 1958) who used the shape of the insemination apparatus (spermatheca) for taxonomic purposes, she also adopted this character to define genera, initially without giving it a particular weight. Meanwhile, she also studied other gamasids, and in 1966 considered the insemination apparatus as the main character for distinguishing families of Gamasida. She distinguished the Phytoseiidae within the Laelapoidea (sic), by the type of insemination apparatus and the dorsal hypotrichy. In 1966, she adopted Lindquist and Evans (1965) chaetotactic nomenclature system in her

Larval morphology of Central European species of genus Stephensia Stainton, 1858 (Lepidoptera, Elachistidae)

The morphology of last instar larvae of Stephensia abbreviatella and Stephensia brunnichella is described and illustrated in detail. The study is based mainly on chaetotaxy of head capsule, as well as thoracic and abdominal segments. Head chaetotaxy of representatives of the family Elachistidae s.s., and chaetotaxy of Stephensia brunnichella are published for the first time. The larvae of studied species may be differentiated mainly by their size and differences in arrangement and length of some setae. The Stephensia larvae are characterized by some rare in the family but most likely plesiomorphic traits, e.g. by comparatively long tactile setae, trisetose L group on AI–VIII, as well as a set of seven tactile setae (D1–2, SD1, L1, L3, SV1, V1) and two proprioceptors (MD1, MV3) on AIX. A few larval characters of potential phylogenetic importance are discussed. The size reduction of the ventral prothoracic shield is supposed to be a potential autapomorphy for the genus Stephensia. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Four new species of fan worms (Polychaeta: Sabellidae) from worldwide localities

Four new species of soft-bottom sabellid polychaetes are described and illustrated. Branchiomma costaricensis n. sp. is described from 31 m depth off Isla del Coco, Costa Rica; Dialychone arabica n. sp. from 105 m depth in the Arabian Sea; Dialychone blakei n. sp. from 487 m depth off Louisiana in the Gulf of Mexico and Paradialychone harrisae n. sp. from 30 m depth in southern California. Branchiomma costaricensis n. sp. is characterized by having microstylodes with the median pair 1.5 times longer than neighbouring pairs, thoracic uncini with two rows of teeth above the main fang, an unspotted body and large interramal eyespots. Dialychone arabica n. sp. has the anterior peristomial ring lobe exposed beyond the collar and a pre-pygidial depression occupying eight segments. In D. blakei n. sp., the anterior peristomial ring lobe is not exposed beyond the collar, the pre-pygidial depression occupies the last four segments and the posterior segments possess thin elongate, narrowly hooded chaetae. Paradialychone harrisae n. sp. differs from the other species of the genus in having the anterior peristomial ring lobe bilobed and exposed beyond the collar, a rectangular ventral collar shield and paleate chaetae with a long mucro.

A new genus and species of phytoseiid mites (Aacari: Mesostigmata) from the Brazilian Atlantic forest

The phytoseiid mite Ragusaseius ferraguti n. gen., n. sp. is described from the primary Atlantic Forest Mata Atlantica in Brazil, based on specimens collected on Cyphomandra calycina Sendth (Solanaceae). This mite is unique in the following combination of characters: setae J3 and J4 present; dorsal setae medium to long, except for J5, and serrated; ventrianal shield anteriorly eroded, containing only JV2 and occasionally ZV2 in addition to circumanal setae.

A New Species of Antennoseius from Australia (Acari: Mesostigmata: Ascidae)

Abstract. Antennoseius (Vitzthumia) ventrianalis sp. nov. is the second species of Antennoseius described from Australia (Acari: Ascidae). It is described from non-phoretic specimens collected from the soil surface. The new species is unique in having three pairs of ventral setae on the ventri-anal shield; the maximum observed in other species is two pairs. It is sexually dimorphic in the degree of fusion of the podonotal and opisthonotal shields and some other minor characters.

Molecular and morphological evidence for a new species status within the genus Euseius (Acari: Phytoseiidae)

The identity of specimens belonging to the genus Euseius Wainstein, 1962 found on several trees in France is investigated. These specimens are morphologically close to Euseius stipulatus (Athias-Henriot, 1960) except for the shape of the spermatheca and the dorsal shield reticulation. The aim of the present study was to determine if these specimens belong to this latter species and if the shape of the spermatheca could be considered a reliable diagnostic character. Thirty-four characters, including idiosomal seta lengths, were measured and molecular tests (12S rDNA, COI mtDNA) were carried out. Although small, significant differences between populations of Euseius sp. were observed. The morphometric differences between E. stipulatus and Euseius sp. were very small except for the seta z2 and for the length of the ventrianal shield, as well as the length and form of the spermatheca. Molecular analyses support that Euseius sp. and E. stipulatus are two different species. Euseius sp. has been described as a new species to science in another publication under the name Euseius gallicus . Reliability of some morphological characters for species diagnosis is discussed.

ChaetopterusandMesochaetopterus(Polychaeta: Chaetopteridae) from the Galapagos Islands, with Descriptions of Four New Species

ABSTRACT. We provide descriptions of five species of Chaetopterus and two species of Mesochaetopterus (Annelida: Polychaeta: Chaetopteridae) based on collections during 2001–2007 and observations from the Galapagos Islands, Ecuador. Chaetopterus galapagensis sp. nov. is a large (ca. 18 cm long) worm that inhabits a U-shaped tube in soft sand substrates. It is characterized by 12 – 14 chaetigers in the anterior region and 7–8 teeth on uncini of region A neuropodia. Chaetopterus charlesdarwinii sp. nov. is of intermediate size (2 – 4.5 cm long) with 9 anterior region chaetigers and a characteristic brown band on the lateral side of the ventral shield and posterior side of anterior region notopodia. It inhabits irregularly curved tubes cemented to the underside of rocks. Worms may occur singly or aggregated, with up to 10 worms in a cluster. Chaetopterus aduncus sp. nov. is 8–10 cm in length, and is characterized by 10 – 11 anterior region chaetigers, characteristic J-shaped tube with one blind end, and prom...

A New Species of <I>Galendromus</I> (Acari: Phytoseiidae): A Case of Intraspecific Variation and Redefinition of <I>carinulatus</I> Species Group

Abstract A new species, Galendromus (Mugidromus) sulamericanus, is described from northwestern Sao Paulo state, Brazil, and it is included in the carinulatus species group Chant and Yoshida-Shaul, which is herein redefined to accommodate this new species. A variation in the insertion of ZV2 seta in the ventral shield was observed in individuals from the same population. A key is provided for all known species of the subgenus Mugidromus Tuttle and Muma.

A new species of Spiochaetopterus (Chaetopteridae: Polychaeta) from the Iheya Seamount off Okinawa in East China Sea, Japan

Spiochaetopterus iheyaensis, a new species of Chaetopteridae (Annelida: Polychaeta) is described from 6 specimens collected by the Deep-Sea Research Vehicle Shinkai 2000 from the deep sea at Iheya Seamount, off Okinawa, Japan. The species is characterized by the coloration of the ventral shield of the anterior region (region A), by having one or two pairs of large cutting chaetae on the fourth chaetiger (A4), and by the morphology of A4 modified cutting chaetae (with inflated semi-circular and pear-shaped in upper view, head lacking teeth), having 2 middle region (region B) chaetigers, and a slender, annulated tube. The new species is compared to Pacific Spiochaetopterus, particularly the ultrastructure of the A4 chaetae.

A new species of Paraseiulus Muma from Iran with a key to the known species (Acari: Mesostigmata: Phytoseiidae)

According to Moraes et al. (2004), twelve species of Paraseiulus Muma are known worldwide, of which six were recorded in Iran (Kamali et al., 2001; Faraji et al., 2007). The genus Paraseiulus is characterized by the absence of caudoventral setae JV2; ventrianal shield sole-shaped, with two pairs of preanal setae and without preanal pores; sternal shield with two pairs of setae; setae ST3 either located on soft cuticle or inserted on platelets and setae ST4 inserted on separate platelets; calyx of spermatheca elongate-tubular, bell-shaped or saccular; fixed cheliceral digit with two or three teeth; legs without macrosetae or with a short macroseta on basitarsus IV. A new species of Paraseiulus is described in this paper and a key is provided to help in the identification of the world species of this genus. The classification system follows Chant and McMurtry (1994) for Typhlodrominae. The notations used for dorsal and ventral setations follow Rowell et al. (1978) and Chant and Yoshida-Shaul (1991) respectively. All measurements are in micrometers (μm). The type material of slide-mounted specimens is deposited in the National Museum of Natural History, Leiden, The Netherlands (RMNH).

Mixturopoda Baker and Monson, a new genus of the uropodine family Metagynuridae (Acari: Mesostigmata) from the British Isles

A new taxon of mesostigmatid mite of the suborder Uropodina is described from damp, rotten straw associated with Dutch barns in NW England. Mixturopoda evansi gen. nov., sp. nov. possesses character states that have not previously been recorded in uropodines, e.g., the female genital shield bears setae st5 and is located behind coxae IV but not within the ventral shield, and barsitarsi II–IV lack seta pd3. Other states are a combination of those used to diagnose currently recognized superfamilies, e.g., subcylindrical, separated coxae I that are inserted in the gnathopodal cavity, absence of pedofossae and paragynial shields, and adult dorsal and marginal shields and deutonymphal dorsal shield undivided. Mixturopoda evansi is placed in the family Metagynuridae on the basis of the posterior position of the female genital shield. Amendments to the diagnoses of the Metagynuridae and its type genus, Metagynella, are proposed.

A new species of Phyllochaetopterus (Chaetopteridae: Annelida) from near hydrothermal vents in the Lau Basin, western Pacific Ocean

Phyllochaetopterus lauensis n. sp., a new species of Chaetopteridae, is described from material collected by the DSV Jason II from the vicinity of hydrothermal vents in the Lau Basin, western Pacific Ocean. The new species is characterized by the coloration and patterning of the ventral shield of the anterior region (region A), the presence of one large cutting chaeta on each parapodium of the fourth chaetiger (A4), the shape of these A4 cutting chaetae (with a pear-shaped head), and presence of two middle-region (region B) chaetigers with foliose notopodia. The new species is very similar to some Spiochaetopterus species, but belongs in Phyllochaetopterus based on its possession of a pair of anterior ‘antennae’, which are in fact cirri of chaetiger one with internal chaetae. The new species is compared to other Phyllochaetopterus species, particularly from the Pacific, and we provide a table for all species currently referred to the genus.

Description of a new species of Phytoscutus (Acari: Phytoseiidae) from Kyushu, Japan

Phytoscutus japonicus n. sp., the first known member of this genus from Japan, is described and illustrated based on females collected from citrus leaves in Miyazaki Pref., Kyushu. It resembles P. acaridophagus (Collyer) in having the dorsal shield with seta J2, but differs in having the opisthoscutum with lobed striae, ventrianal shield noticeably wider than long, and leg IV with 3 macrosetae.

The suspected synonymy of Kampimodromus hmiminai and Kampimodromus adrianae (Acari: Phytoseiidae): morphological and molecular investigations

Kampimodromus hmiminai McMurtry and Bounfour, 1989 and Kampimodromus adrianae Ferragut and Peña-Estévez, 2003 are two morphogically close species belonging to the family Phytoseiidae. They are the only two species within the genus Kampimodromus Nesbitt, 1951 that bear six solenostomes and a reduced ventrianal shield. Only some characters, such as the idiosomal seta lengths, idiosomal dorsal ornamentation, and setae ornamentation, distinguish them. Kampimodromus hmiminai has being reported from France and Morocco and K. adrianae from the Canary Islands. Our study tests the hypothesis of synonymy between these two species, using morphological measurements and molecular typing (mtDNA, cytochrome C oxidase I (COI)). The differences in idiosomal setae lengths between K. adrianae and K. hmiminai seem to be large enough to support their species status. However, genetic distances between these two species correspond to an intraspecific range of variation. According to the present data, K. adrianae and K. hmiminai could be considered synonyms, with morphologic differentiation as a result of geographic isolation. This result indicates that comparative setal length, seta serration, and dorsal shield ornementation should be used with caution for species differentiation within the genus Kampimodromus .

A new genus and species of phytoseiid mites (Acari: Mesostigmata) from southern Tunisia, with discussion of its phylogenetic position

The phytoseiid mite Africoseiulella flechtmanni gen. nov., sp. nov. is described from specimens collected on an unknown small weed growing under palm trees in an oasis in southern Tunisia. This mite is unique in the following combination of characteristics: dorsal shield of both sexes and male ventri-anal shield eroded; all dorsal shield setae minute; peritreme very short; setae JV1, JV3, JV4 and ZV1 absent; hypostome elongate; chelicera with long median segment but digits short and edentate; legs short and without macrosetae. The phylogenetic relationships of this new genus with close taxa are analysed; its taxonomic position within the Typhlodrominae is uncertain.

Cladistic analysis of the subfamily Trichobranchinae (Polychaeta: Terebellidae)

To assess the phylogenetic interrelationships of Trichobranchinae (Polychaeta: Terebellidae), we present the results of a cladistic analysis based on morphological characters coded as contingent. We also present an alternate way to number anterior segments, based on a reinterpretation of prostomial and peristomial morphologies in different genera. The ingroup terminals included 28 species, and the outgroup included one species of Ampharetidae and four species belonging to other subfamilies of Terebellidae. The monophyly of Trichobranchinae is clearly supported by the presence of long shafted uncini in thoracic neuropodia and by the absence of ventral shields. Species of Terebellides share lamellate branchiae, uncini with a long and narrow manubrium without denticles and uncini with a long and sharp main fang in the eighth segment. Species of Octobranchus share subquadrate branchiae on segments 3, 4 and 5, notopodia first present from segment 4, and uncini with a long shafted manubrium first present from segment 6. The autapormophy for Unobranchus is the presence of a single filiform branchia on segment 3. Artacamella falls into one of the Trichobranchus clades and is treated as a junior synonym of the latter.

A new genus and species of Phytoseiid mite (Acari: Phytoseiidae) from Brazil

The phytoseiid mite Macrocaudus multisetatus n. g., n. sp., is described from Brazil based on specimens collected on Salvinia sp. (Salviniaceae). This mite is unique in the following characteristics at different taxonomic levels: larvae with seta Z4 not considerably longer than most dorsal setae, nymphs and adults with J3 present, J5 unusually long and subequal to Z5, males with all 8 caudoventral setae in addition to paraanal and postanal setae (Phytoseiidae); both sexes with seta JV3 present and on the ventrianal shield (Amblyseiinae).

Revision of the genera Amblydromella Muma and Anthoseius de Leon (Acari: Phytoseiidae)

Amblydromella Muma is revised and the following subgenera are described: Amblydromella Muma, Aphanoseia Wainstein, Lindquistoseia n. subgen., and Prasadoseia n. subgen. The monotypic genus Anthoseius De Leon is similar to Amblydromella, but can be separated on the basis of the shape and length of the dorsal setae, short, thick legs, width of peritreme, modified cheliceral denticles, a ventrianal shield that is often fragmented, presence of z3 in protonymph (absent in protonymph of Amblydromella), host plant, and geographical distribution

Spiochaetopterus nonatoi, a new species of Chaetopteridae (Polychaeta) from Brazil: biogeographical consequences

A new species Spiochaetopterus nonatoi is described from the south-eastern coast of Brazil, the type locality being Flamengo Bight, 6-m depth (23°30′S 45°06′W). This species is distinguishable from already erected species of the same genus by the following characteristics: oculate specimens of large size; maximum segments, 197 (N=15); maximum tube length, 45 cm; maximum body length, 20 cm; orange coloration of the fore part (peristomium and segment 1) and of the ventral shield on segments 6–7; shape of the specialized enlarged cutting seta on A4 with an obliquely truncated distal end; this slightly concave section is heart-shaped and clearly asymmetrical; segments B1 and B2 with one lobe on the neuropodia. This additional description in the genus Spiochaetopterus confirms the limited geographical area of each species in this genus. In spite of the probable ability of planktonic larvae of Spiochaetopterus to disseminate throughout the Atlantic Ocean, the benthic adults of each species cover only a limited geographical area. In particular, the stem species S. costarum loses its cosmopolitan character.

Phylogenetic analysis of the Amphitritinae (Polychaeta: Terebellidae)

Abstract The phylogenetic relationships of the Amphitritinae (Polychaeta: Terebellidae) were studied using parsimony analysis of 22 external morphological characters. To choose outgroups to polarize the characters, I carried out a preliminary analysis of the relationships of the four terebellid subfamilies and the Trichobranchidae. The single most parsimonious tree from the analysis supports monophyly of the Terebellidae by the presence of ventral glandular shields. However, this character is homoplasious within the Terebellomorpha, and further evaluation of the Terebellidae is recommended.ArtacamaandThelepuswere chosen as outgroups for the analysis of amphitritine genera. The generic level analysis yielded seven equally parsimonious trees, which are consistent in their topologies except for the relationships among seven genera in one large clade. In all trees,Artacamais the sister taxon to a large clade within the Amphitritinae; the Artacaminae is therefore synonymized with the Amphitritinae, which is diagnosed by the presence of double rows of uncini. Within the Amphitritinae, the status of several monotypic genera is questioned; plesiomorphic character states indicated by the analysis are discussed. The results presented are offered as working hypotheses of the relationships among amphitritine genera. The large number of homoplasies indicated by the analysis emphasizes the need to further evaluate these hypotheses using additional characters. With a robust phylogenetic hypothesis of amphitritine relationships, a re-classification of the group based on apomorphic character states can be undertaken, and questions regarding the evolution of morphological characters, reproductive modes, or biogeographical patterns can be properly addressed.