Observations on the subgenus Argas (Ixodoidea: Argasidae: Argas). 19. Description of the larva of the Palearctic cormorant parasite A. (A.) macrostigmatus

Larvae of 19 of the 21 species of the Argas subgenus Argas are already described. One of the two exceptions is A. (A.) macrostigmatus; we describe the larva of this species from wet nests of the crested cormorant, Phalacrocorax aristotelis, from Corsica, France. As in the adult and nymphal stages, this larva has an uncovered Haller's organ, a character shared in Palearctic members of this large genus only with A. (A.) polonicus, a Central European parasite of rock pigeons. Available larval samples of both species are indistinguishable. However, adult and nymphal A. (A.) macrostigmatus are unique for their exceptionally large spiracular plates. These are the only Argas (Argas) species which differ distinctly as adults and nymphs but hardly or not at all as larvae. Argas (A.) macrostigmatus was previously known only from a nest of the crested cormorant in the Black Sea. Ukrainian SSR.     

Observations on the subgenus Argas (Ixodoidea: Argasidae: Argas). 18. Haller's organ roof and anterior pit setae

Adults of 18 of the 22 species constituting the subgenus Argas, which parasitize birds nesting and resting in rocky habitats in each faunal region of the world (15 species) or in trees (e species) (2 Neotropical, 1 Nearctic), were studies by SEM. In each except three Neotropical species, the nine setae of the anterior pit of tarsus I are arranged in an anterior group (1 serrate, 1 setiform, 1 conical) and a posterior group (2 fine, e porose, 2 grooved), or the two groups are more or less confluent. Abnormally, additional setae may occur on one or both tarsi of a single specimen. In one Neotropical species, only the three anterior group setae are present. In three Neotropical species, only these three setae and a fourth seta are present (whether 6 or 5 additional setae are concealed within the tarsal structure should be investigated). The Haller's organ capsule is entirely open (unroofed) (3 species), roofed posteriorly and open anteriorly (7 species), or mostly roofed by a plate which is pierced by one large aperture and by more or less numerous, small, or medium-sized perforations (8 species plus one other not studied by use). This study suggests that the structure of Haller's organ has evolved in different lines in response to a multiplicity of biologic al factors related to the behavior and habitat of individual species.     

Ultrastructural studies of Haller's organ in the argasid tick, Argas tridentatus (Argasidae)]

Haller's organ in A. tridentatus consists of a capsule and an anterior group of sensilla. The capsule is the hollow in the cuticle on the dorsal surface of the first tarsus, where 4 pored hairs of olfactory sensilla are situated under the cover of the roof, formed by an anostomosis of the upper brunches of pleomorphs (capsule's bottom non-sensory cuticular outgrowths). The canal of the accessory ampullaceous sensillum opens in a capsule near the bottom. The anterior group of sensilla consists of two parts: proximal part, containing pored grooved and thin hairs, is homologous to the anterior grouf of ixodid ticks, and distal one which has no homologues in ixodids. Fine structure of all the sensilla in the mentioned parts of Haller's organ is described in detail.     

Observations on the subgenus Argas (Ixodoidea: argasidae: Argas). 17. Argas (A.) polonicus sp. n. parasitizing domestic pigeons in Krakow, Poland.

Argas (A.) polonicus sp. n. is described from males, females, nymphs, and larvae from the steeple tower of St. Mary's Church, Karkow, Poland, where it feeds on domestic rock pigeons, Columba livia Gmelin. This species is related to the widely distributed Eurasian A. (A.) vulgaris Filippova and to certain other species of the eastern area of the Palearctic Faunal Region; it differs distinctly from A. (A.) reflexus (Fabricius) of western Europe. Comparative study under the light microscope. and especially under the scanning electron microscope, reveals numerous structural differences in adult and immature stages of these species, chiefly in the Haller's organ roof of each stage, adult body shape and integumental formations, dental formulae, and setal lengths and numbers on the larval dorsum.     

Sense organs in post-embryonic stages of Hyalomma marginatum marginatum Koch, 1844 (Acari: Ixodida: Ixodidae). I. Tarsal sensory system.

Light and scanning electron microscopic studies showed the differences in morphology and in size of Haller's organ in larvae, nymphs and adults (females and males) of Hyalomma marginatum marginatum Koch, 1844. The length of the anterior pit setae increases during post-embryonic development. The localization of these setae is the same in all stages. Six setae (one porose seta, two grooved setae, two fine setae, one conical seta) contain anterior pit of various developmental stages. In nymphs and adults more numerous pores appear on the wall surface of porose seta than in the larval stage. The structure of the capsule roof also differs in various developmental stages. Haller's organ of Hyalomma m. marginatum shows great degree of morphological development which is connected with the complicated life cycle and feeding behaviour of this tick species.     

Regeneration of Haller's sensory organ in the tick, Ixodes rubicundus (Acari: Ixodidae)

A study of regeneration in nymphs and adults of the South African tick Ixodes (Afrixodes) rubicundus, from which the forelegs had been amputated during the previous instar, revealed that the structural changes in regenerated Haller's sensory organs resemble those observed in other ixodid ticks, in particular in another prostriate tick, Ixodes (Ixodes) ricinus. The adult regenerates re-establish their atavistic features in terms of the increased number of different sensilla on the distal knoll, in the anterior pit and the capsule. The nymphal regenerates, in contrast, re-establish the features of the previous instar through a reduction in the number of some sensilla on the distal knoll and in the post-capsular area. The structural changes in different compartments of the organ appear independent. The phenomenon of regenerative induction through the appearance of specific changes in Haller's organ of the contralateral non-treated foreleg is probably characteristic only of prostriate ticks. A unique modification in the regenerated Haller's organ as revealed by duplication of the Haller's organ capsule was discovered in both I. rubicundus nymphs and adult ticks.     

Regeneration of Haller's sensory organ in the tickIxodes ricinus L.

Amputation of legs in nymphs of ticks, obtained from the first laboratory generation, resulted in regeneration of the legs after moulting to adults. Haller's sensory organ on the upper surface of each foreleg tarsus was significantly modified following regeneration. Haller's organ in non-amputated legs of the experimental ticks remained unchanged, being comparable to controls.Pored olfactory sensilla in the anterior pit, in a capsule and on a distal knoll usually increased in number, as well as grooved, thin and conical sensilla. Bordering gustatory and double-walled postcapsular sensilla either decreased or increased in number. All additional sensilla were consistent in their location. Form of the anterior pit and capsule's aperture also deeply changed after the regeneration. The authors distinguish this changes as atavistic.No correlation between changes in different parts of the organ were found.A phenomenon of induction was discovered in our study: if a distal part of tick's gnathosoma was amputated together with the left foreleg, Haller's organ in the right, untreated leg possessed the same changes after moulting as the regenerated organ in the previously amputated left foreleg.     

Bat ticks of the genus Argas (Ixodoidea: Argasidae). 13. Haller's organ roof and anterior pit setae in Carios and Chiropterargas

Adults of 4 of the 6 species constituting the subgenus Carios and of 3 of the 4 species constituting the subgenus Chiropterargas were studied by scanning electron microscopy. All species parasitize Old World cave-dwelling insectivorous bats (Microchiroptera). The anterior pit setae number 10 in Carios and 10 or 11 in Chiropterargas. In most Carios, the setiform seta is replaced by a second serrate seta. In 2 of the 3 studied Chiropterargas species, 1 of the 2 grooved setae is exceptionally long. Porose setae number 3 in Carios and 3 or 4 in Chiropterargas. The Haller's organ roof in both subgenera is solid, lacking perforations; the aperture is narrowly transverse in Carios, irregularly wide or wide and transverse in Chiropterargas; uniquely, 1 or 2 sensilla protrude from the aperture of Chiropterargas species. The protruding sensilla and long grooved seta of Chiropterargas suggest a probably distinctive sensory-behavior pattern common to these ticks. Other morphological characters are discussed and compared to show relationships between these 2 subgenera and the subgenera Argas and Persicargas and distinctive characters present only in adult and/or larval Carios and Chiropterargas.     

Morphology and structural organization of Haller's organ during postembryonic development ofArgas (Persicargas) walkerae (Ixodoidea: Argasidae)

Scanning-electron-microscopic investigations of Haller's organ in larvae, nymphs I, II, III and IV, and male and female adultArgas (Persicargas) walkerae ticks showed that morphology and structural organization change during postembryonic development. Stage-dependent differences existed regarding setal numbers of the anterior pit as well as formation and reticulation of cuticular projections in the capsule cavity. The anterior pit increased in size in the course of postembryonic development. It contained only seven setae in larvae, one conical, setiform and grooved seta each as well as two porose and fine setae. Nymphs I, II, III and IV and adult ticks had equal numbers of setae; however, one additional unilaterally serrate and grooved seta each were present. Setal length increased continuously during postembryonic development and attained maximum values in adult ticks. The capsule consisted of roof and cavity and was located distinctly lateral in larvae, slightly lateral in nymphs I and II, and in all other stages directly on the longitudinal axis of tarsus. The capsule roof showed a reticular structure. The slit-like main aperture was located peripherally and arranged transversally to the longitudinal axis of tarsus I in larvae. Nymphs and adult ticks had a central, circular main aperture. Stage-dependent cuticular projections of varying form protruded into the capsule cavity. Larvae had only single, free-standing projections which ramified slightly and communicated with each other. Projections were more heavily reticulated in nymphs I and II. In nymphs III and IV as well as male and female adult ticks, a long centrally situated tube of reticular appearance was seen, which was supported by a large number of radially organized and interlocking pillars and communicated with the capsule roof. In all tick stages there were always four porose setae present, arranged on the capsule floor.     

Ultrastructure of Haller's organ in the tick Amblyomma americanum (L.)

Summary Haller's organ on the tarsus of the tick Amblyomma americanum (L.) (Acarina: Ixodidae; nymphal stage) was studied by scanning and transmission electron microscopy. It consists of a distal bristle group, (the anterior pit), and a proximal capsule which encloses several sensilla. The seven sensilla of the anterior pit (A1–A7) are all thick-walled and multi-innervated (2–9 neurons), but at least three different types can be differentiated. Sensilla A1 and A2 possess large, plugged pores (>1000 Å) and are the only sensilla with branching dendrites. A3 and A5 are characterized by a spoke-wheel arrangement of the cuticle wall and very fine pores (100–200 Å) penetrating the spokes centrally; A4, A6, and A7 do not exhibit any pore system but a single opening at the bristle tip is assumed.The capsule contains seven thin-walled, blunt-tipped sensilla, and several non-sensory cuticular projections (pleomorphs). All of these sensilla possess large plugged pores in the cuticle wall and numerous dendritic branches of several neurons (3–5) in the lumen. Glandular openings were found inside the capsule; their significance is discussed.The fine structure of Haller's organ supports the functions postulated by Lees (1948), namely olfaction for the capsule and humidity reception (among others) for the anterior pit.This research was supported in part by the Office of Naval Research, and by NIH Training grant ES 00069. Paper no. 3459 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh.     

革蜱成虫哈氏器的扫描电镜观察

本文报道了用扫描电镜观察革蜱属8种成虫的哈氏器.其中三种成虫(阿坝革蜱D. ahaensis、金泽革蜱D. auratus和中华革蜱D. sinicus)的哈氏器结构是首次报道,并与其他属6种成虫的哈氏器进行了比较,以阐明其形态特征及其在分类中的意义.另外,还将这14种成虫哈氏器与各自未成熟期的哈氏器进行了比较.分析和讨论了同种不同时期哈氏器结构的异同.东洋区的金泽革蜱和古北区的革蜱种类间,在孔毛形状,位置及基盘数目上有明显差别,而后者中,边缘革蜱D. marginatus的孔毛位于近端外侧,草原革蜱D. nuttalli和网纹革蜱D. reticulatus的孔毛位于远瑞外侧,其余种类无明显差别.     

Three new species of Antricola (Acari: Argasidae) from Brazil, with a key to the known species in the genus

Three new species of Antricola (Acari: Argasidae) are described from adult specimens collected on bat guano in different caves in Brazil. The female of Antricola guglielmonei n. sp. is easily determined by the presence of 2 smooth, depressed areas lacking setae in the posterolateral portions of the dorsum of the idiosoma, together with the partial fusion of the tubercles in the anteromedian portion of the idiosoma. The male of this species has a small spiracular plate surrounded by a pattern of tubercles disposed concentrically in its dorsal portion. Both sexes have cervical grooves very slightly marked. Antricola delacruzi n. sp. represents the only Antricola species with the dorsum of the idiosoma devoid of tubercles in both sexes and with scarce and minute setae placed over the smooth cuticle. The female of A. inexpectata n. sp. is known only from a few specimens. In this species, lines of smooth cuticle lacking setae separate the tubercles of the dorsum. In addition, there are 3 clumps of plumose setae close to the spiracular plate, in the ventrolateral portions of the idiosoma, in 3 well-delimited regions over cuticular thickenings. These 3 species share the peculiarity of a Haller's organ with the anterior pit bearing only 7 + 2 setae. The collection of these new species in Brazilian caves greatly expands the known range of the genus. A key to the adults of all known species of the genus is provided.     

The fowl tick, <Emphasis Type="Italic">Argas (Persicargas) persicus</Emphasis> (Ixodoidea: Argasidae): Description of the egg and redescription of the larva by Scanning Electron Microscopy

This scanning electron microscopy study revealed that the egg of Argas persicus was covered with chorion which appeared as a wrinkled layer containing regions of three textures. The first had elevated parts of slightly rough surface. The second had irregular smooth elevations; each carried numerous parallel horizontal foldings with vertical ridges. The last region had rough surface with irregularly shaped projections. Following the removal of the chorion, shell was observed to have one polar micropyle and numerous slit like openings. Length (L), width (W) and L/W ratio of the egg were measured. Investigation of larvae revealed extensively folded integument of idiosoma and spherical or elongated tubercles on dorsal plate. Mouth enclosed between ventral hypostome and two dorsal chelicerae. Hypostome carried four longitudinal rows of conical denticles. Each chelicera was made up of two segments; the basal one appeared as a pocket for the distal one. Haller’s organ consisted of an anterior pit containing seven sensilla and a posterior capsule with four apertures. Distribution of chemo- and mechano-sensilla on the body was examined. Measurements of whole body, idiosoma, dorsal plate, capitulum, hypostome, palp and different types of sensilla both on the body and Haller’s organ are also presented.     

First data on the molecular phylogeography of scincid lizards of the genus Mabuya

A 487-bp fragment of the mitochondrial 16S rRNA gene was sequenced in 26 species of the circumtropical lizard genus Mabuya and used to analyze phylogenetic relationships within the genus. The species from Africa and Madagascar formed a monophyletic group relative to the included Asian and South American taxa. The Malagasy species included (M. elegans, M. cf. dumasi, and M. comorensis) did not appear as a monophylum. Combined and separate analysis of the 16S data and additional sequences of the mitochondrial 12S rRNA, ND4, and cytochrome b genes (a total of 2255 bp) in one Asian, two Malagasy, and two African species also did not result consistently in a monophyletic grouping of the Malagasy taxa. However, a monophylum containing African and Malagasy taxa was strongly supported by the combined analysis. These preliminary results indicate that Mabuya probably colonized Madagascar from Africa through the Mozambique Channel.     

Regeneration of Haller's sensory organ in two species of hard ticks of the genus Haemaphysalis (Acari: Ixodidae)

A study of Haller's organ regeneration in nymphs and adults of Haemaphysalis turturis and parthenogenetic females of H. longicornis, from which the forelegs had been amputated during the previous instar, revealed structural changes in regenerated organs. The adult regenerates reestablished atavistic structural features, while the nymphal regenerates retained larval features, which is typical of regenerates of two other genera examined previously (Ixodes and Hyalomma). Data on regeneration of Haller's sensory organ testify to an ancient character of the genus, standing closely to the base of the phylogenetic tree of hard ticks.     

Revision of the Malagasy species of the genus Tricalysia (Rubiaceae)

The Malagasy representatives of the large African genus Tricalysia (tribe Coffeeae s.l.) are revised. Three Malagasy species were hitherto recognized in the genus, namely T. cryptocalyx , T. madagascariensis , and T. ovalifolia . In this study, two species, T. boiviniana and T. leucocarpa , are transferred from the genus Hypobathrum and seven new species and two new subspecies are described, raising the species number for Tricalysia to a total of 12. This marked increase in species number is a recurring pattern for many Malagasy genera in systematically poorly known families such as Rubiaceae. All the species are described in detail and illustrated, and a list of exsiccatae and a distribution map are provided. Furthermore, the characters of the Malagasy taxa are compared with those of the continental African species, and their infrageneric status is discussed. With the exception of T. ovalifolia , a member of subgenus Empogona , all Malagasy species belong to subgenus Tricalysia . Because of their unisexual flowers, these species cannot be accommodated within one of the four existing sections in subgenus Tricalysia . A new section, Androgyne , is therefore recognized.  © 2007 National Botanic Garden of Belgium. Journal compilation © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 83–126.     

Opening the black box: phylogenetics and morphological evolution of the Malagasy fossorial lizards of the subfamily "Scincinae"

The island of Madagascar harbors a highly endemic vertebrate fauna including a high diversity of lizards of the subfamily "Scincinae," with about 57 species in eight genera. Since limb reduction seems to have been a common phenomenon during the evolution of Malagasy "scincines," diagnosing evolutionary relationships based on morphology has been difficult. Phylogenetic analyses of multiple mitochondrial DNA sequences including the entire ND1, tRNA(LEU), tRNA(ILE), tRNA(GLN) genes, and fragments of the 12S and 16S rRNA and tRNA(MET) genes were conducted to test the monophyly of the largest genus Amphiglossus, and to evaluate the various formal and informal species groupings previously proposed for this species-rich group. A further objective was to determine the phylogenetic placements of the several greatly limb-reduced and limbless Malagasy "scincines" and ascertain whether any of these are derived from within the morphologically plesiomorphic Amphiglossus. As limb reduction in skinks is mostly associated with body elongation via an increase in the number of presacral vertebrae, we evaluate the pattern of evolution of the numbers of presacral vertebrae in the context of our phylogeny. We demonstrate that Amphiglossus as currently diagnosed is non-monophyletic, and the species fall into two major groups. One of these groups is a clade that contains the included species of the subgenus Amphiglossus (Madascincus) among other species and is a member of a larger clade containing Paracontias and Pseudoacontias. In the second group, the nominate subgenus Amphiglossus (Amphiglossus) forms several subclades within a larger clade that also contains Androngo crenni and Pygomeles braconnieri, and is sister to Voeltzkowia. All analyses provide strong support for the monophyly of Paracontias and Voeltzkowia. Based on the preferred phylogenetic hypothesis and weighted squared-change parsimony we show that the ancestor of the Malagasy clade was already elongated and had a moderately high number of presacral vertebrae (46-48), which is hypothesized to be the ancestral condition for the whole Malagasy "scincine" clade. We further demonstrate that both multiple increases and reductions of presacral vertebrae evolved in many clades of Malagasy "scincines" and that the use of presacral vertebrae as a major character to diagnose supraspecific units is dubious. Based on our results and published morphological evidence we consider Scelotes waterloti Angel, 1930 to be a junior synonym of Amphiglossus reticulatus (Kaudern, 1922).     

Sinharaja gen. n., a new Uropodina mite genus from Sri Lanka with description of two new species (Acari: Mesostigmata: Uropodidae)

A new Uropodina genus (Sinharaja gen. n.) is described on the basis of two new species (S. ceylonensis sp. n. and S. sinhala sp. n.) from Sri Lanka. The new genus differs by the strongly sclerotised dorsal lines, pentagonal pygidial shield, the shape and length of dorsal setae and the shape of first and fourth hypstomal setae, internal malae and epistome from the other known Uropodina genera.