Morphological diversity of pedicels in phoretic deutonymphs of Uropodina mites (Acari: Mesostigmata)

The pedicel is a structure that connects the phoretic deutonymph of Uropodina mites with its carrier and enables dispersal. The shapes, lengths and diameters of pedicels formed by Uropoda orbicularis, Trichouropoda ovalis, Uroobovella pulchella and Uroobovella nova were studied by scanning and light microscopy. Pedicels of U. orbicularis and T. ovalis have the shape of a straight stalk. In U. pulchella, the pedicel is extremely short, irregularly shaped and composed of homogeneous material. The longest pedicel is found in U. nova and it may be helically coiled in this species. The length of the pedicel is positively correlated with deutonymph body size between species, but not within species. Pedicels of U. orbicularis and U. pulchella have the largest diameter. The pedicel diameter in U. orbicularis and T. ovalis is inversely proportional to its length, but not in U. nova and U. pulchella. The constituent of pedicel stems in U. pulchella is homogeneous, whereas in U. orbicularis and T. ovalis it contains a bundle of tightly packed fibres. In U. nova coiled pedicels are comprised of two layered materials of different electron density, one of which is electron lucid and located peripherally. Hypotheses on the origin of the pedicel are proposed.     

Morphology and molecular phylogeny of two new brackish-water species of Amphisiella (Ciliophora,Hypotrichia), with notes on morphogenesis

Two new species of the taxonomically confused genus Amphisiella were isolated from brackish-water habitats in southern China, and their morphology and morphogenesis were investigated. The genes coding for small subunit (SSU) rRNA were sequenced in each species and included in a phylogenetic analysis with all data available from nominal species of Amphisiella and related hypotrichs. Both new species are diagnosed by an elongate body shape, yellow-brown/grey-brown cell color, one kind of cortical granule, and two macronuclear nodules. The cortical granules in A. pulchra sp. n. are grouped in small clusters which are irregularly distributed both ventrally and dorsally; in A. candida sp. n., they are irregularly and sparsely distributed ventrally and form longitudinal stripes dorsally. The ontogenetic processes of both species show similarities to those of other congeners. Phylogenetic trees based on SSU rRNA gene sequences suggest that the family Amphisiellidae is a paraphyletic assemblage. The results further demonstrate that two isolates identified as Amphisiella annulata (DQ832260 and GU170843) are very likely cryptic species, and a sequence identified as A. milnei (DQ845293) may belong to a genus other than Amphisiella.     

Antennal sensilla and their possible functions in the host-plant selection behaviour of Phenacoccus manihoti (Matile-Ferrero) (Homoptera : Pseudococcidae)

Nine different types of sensilla have been identified on the antenna of the cassava mealybug Phenacoccus manihoti (Homoptera : Pseudococcidae) with scanning and transmission electron microscopes. Trichoid sensilla, distributed on all segments of the antenna and innervated by a single mechanoreceptive dendrite, have the characteristics of exteroceptors. A campaniform sensillum located on the pedicel and one basiconic sensillum on the flagellum have the characteristics of proprioceptors. Coeloconic sensilla, located ventrally on the pedicel and flagellum, related to poreless sensilla with inflexible sockets, have the characteristics of thermo/hygroreceptors. Uniporous sensilla with a mechanoreceptive dendrite (smooth pegs P1 and P2, grooved pegs P3) and multiporous chemosensilla (grooved pegs P4 and P5), present on the tip of the flagellum, have, respectively, the characteristics of gustatory and olfactory receptors. The results of this study seem to suggest that the cassava mealybug has sensory equipment on its antennae that can detect, by olfaction and contact, chemicals released by the plant.     

Seromucous anal gland in a New World hystricognath rodent Thrichomys apereoides (Lund, 1839)

New World species of the Hystricognathi comprise a group of rodents that exhibit poorly understood social behaviour. One such species, the echimyid Thrichomys apereoides, has a behavioural and social repertoire which suggests the use of its eversible anal gland in communication between individuals; however, no information on the morphology of this gland is available. In this study, the anal gland of nineteen adult individuals (11 males and 8 females) was analysed through histological and histochemical techniques. The gland was located in the submucosal of the anal region, cranial to the anus, and had an opening located dorsally in the rectum mucosa at approximately 1 mm from the anus. The gland was characterized as seromucous, secreting neutral glycoprotein. Not all individuals studied presented secretion in the glandular ducts, indicating a possible functional variation in the gland. This was the first record of an anal gland of the seromucous type in rodents.     

Description of Pratylenchoides sheri n. sp. (Nematoda: Pratylenchidae)

Pratylenchoides sheri n. sp., a bisexual species from the Pacific coastal area of California, is described and illustrated. Its most distinctive characters are the esophageal glands slightly overlapping the intestine dorsally, the large ventrally slanting esophago-intestinal valve, the lack of labial sectors in the first lip annule, the presence of males, and apparently functional spermatheca. Pratylenchoides sheri is morphologically similar to P. magnicauda, but differs in length and labial conformation, its more anterior vulva, and the presence of males. Relationships of head and esophagus gland lobe characters of P. sheri are compared to other Pratylenchoides species.     

Onychiurid species from Wanda Mountains in China,with descriptions of two new species (Collembola,Onychiuridae)

A checklist of onychiurid species from the Wanda Mountains in China is presented. Eighteen species belonging to twelve genera have been found, including two new species. Bionychiurus qinglongensis sp. n. can be easily distinguished from other known species of the genus by the absence of pseudocelli on Th. I tergum and fewer number of vesicles in postantennal organ. Onychiurus heilongjiangensis sp. n. is diagnosed by pseudocellar formulae as 32/133/33352 dorsally and 3/011/31120 ventrally, parapseudocellar formula as 0/000/111001+1^m, ratio of anal spine/unguis as 0.6, unguiculus without inner basal lamella, and male ventral organ absent.     

Morphology,ultrastructure and functional role of antennal sensilla in off-host aggregation by the bed bug,Cimex lectularius

After blood feeding on a host, bed bugs, Cimex lectularius, assemble in aggregation sites away from the host. Off-host aggregation is mediated by a combination of mechanical and chemical stimuli associated with bug feces. Partial antennectomies indicated removal of flagellomeres did not affect aggregation, but removal of the whole pedicel or its distal half significantly reduced (P < 0.01) aggregation, suggesting that sensilla related to off-host aggregation occur on the distal half of the pedicel. Scanning electron microscopy (SEM) revealed that serrated hairs were distributed throughout the pedicel, but newly described smooth hairs were present mainly on the distal half, and a distinct patch of grooved pegs, smooth pegs and immersed cones was present on the posterior edge of the distal half of the pedicel in adults, but not in nymphs. Numbers of different types of sensilla increased significantly during metamorphosis from first instar to adult (P < 0.05), but were similar between genders (P = 0.11) and between females from a laboratory and field strain of bugs (P = 0.19). Transmission electron microscopy (TEM) revealed that cuticular pores were present in the two types of pegs, indicating that the pegs have an olfactory function. The smooth hairs resembled gustatory sensilla previously described in Cimex hemipterus F. The existence of both olfactory and gustatory sensilla on the distal half of the pedicel suggests those sensilla may be the sensory basis of off-host aggregation behavior.     

A new genus and species of darkling beetles of the tribe Helopini (Coleoptera,Tenebrionidae) from Turkey

A new genus and species Microdocnemis xerophilicus gen. et sp. n. of the tenebrionid-beetle tribe Helopini is described from southwestern Turkey. The new genus belongs to the cylindrinotoid group of genera and is closely related to the genus Odocnemis Allard, 1876 in the structure of the male genitalia and female genital tubes and in the denticulation of the inner margin of the fore tibia. Microdocnemis differs from Odocnemis in the following characters: body very weakly flattened dorsally and ventrally; apical part of elytra, body ventrally, and epipleura with hairs; anal sternite with double bordering; apical margins of tibiae with short thick spines. The only species of the new genus inhabits xerophytic stony biotopes and has been found under stones; the species of the genus Odocnemis live on tree trunks covered with lichens.     

The Esophageal Glands of Pratylenchus Filipjev and Apratylenchoides belli n. gen. n. sp. (Nematoda: Tylenchoidea)

The esophageal glands in the genus Pratylenchus occur in a large, single ventral lobe except for four populations in which a few specimens had the glands located dorsally. Apratylenchoides belli n. gen. n. sp. in the subfamily Radopholinae is proposed for a species having two esophageal glands in a large dorsal lobe and one gland in a smaller, shorter ventral lobe.     

Larva of the leaf beetle Labidostomis longimana (Coleoptera, Chrysomelidae, Clytrinae)

The first- and the last-instar larvae of the leaf-beetle Labidostomis longimana are described in detail for the first time. The last instar larva is morphologically close to L. sibirica larva and differs from it in the absence of a projection in the medial emargination of the labrum, in the presence of 7 spiniform setae on the tibiotarsus ventrally, 11–13 narrow simple setae on the tibiotarsus dorsally, and fine rugae on the larval case.     

Physiological Studies on Pea Tendrils: VI. The Characteristics of Sensory Perception and Transduction

Tendrils may be said to possess a sense of touch, and the direction and amplitude of the coiling response can be used to define the characteristics of this sense. These characteristics are, first, that the tendril will coil only in response to ventral mechanical stimulation, that this coiling can be inhibited by subsequent dorsally presented stimulation, and that dorsal stimulation alone causes no coiling. This phenomenon seems to be due to some asymmetry in the response system. Second, the nature of the response is always determined by the location (i.e., dorsal or ventral) of the last stimulation the tendril experienced. Third, the ability of dorsally presented stimulation to reverse ventrally stimulated coiling is gradually lost. Complete escape from reversibility is attained if the interval between ventral and dorsal stimulation reaches 9 minutes. Fourth, the magnitude of response is determined by both the number and the frequency of the stimuli. Both ventrally stimulated coiling and dorsally stimulated inhibition of coiling can be temporarily stopped by a 9-minute cold break at 10 C, given immediately after stimulation. As soon as the tendrils are restored to room temperature, they proceed to respond to the stimulus.     

Anatomy and ultrastructure of dermal glands in an adult water mite,Teutonia cometes (Koch, 1837) (Acariformes: Hydrachnidia: Teutoniidae)

Organization of dermal glands in adult water mites Teutonia cometes (Koch, 1837) was studied using light-optical, SEM and TEM methods for the first time. These glands are large and occur in a total number of ten pairs at the dorsal, ventral and lateral sides of the body. The slit-like external openings of the glands (glandularia) are provided with a cone-shaped sclerite, and are combined with a single small trichoid seta (hair sensillum), which is always situated slightly apart from the anterior aspect of the gland opening. Each gland is formed by an epithelium encompassing a very large lumen (central cavity) normally filled with secretion that stains in varying intensity on toluidine blue stained sections. The epithelium is composed of irregularly shaped secretory cells with an electron-dense cytoplasm and infolded basal portions. The cells possess a large irregularly shaped nucleus and are filled with tightly packed slightly dilated cisterns and vesicles of rough endoplasmic reticulum (RER) with electron lucent contents. Dense vesicles are also present in the apical cell zone. Some cells undergo dissolution, occupy an upper position within the epithelium and have a lighter cytoplasm with disorganized RER. Muscle fibers are regularly present in the deep folds of the basal cell portions and may serve to squeeze the gland and eject the secretion into the external milieu. The structure of these dermal glands is compared with the previously described idiosomal glands of the same species and a tentative correlation with the glandularia system of water mites is given. Possible functions of the dermal glands of T. cometes are discussed.     

Description of a new species of <Emphasis Type="Italic">Amblyomma</Emphasis> Koch, 1844 (Acari: Ixodidae), parasite of deer (Artiodactyla: Cervidae) and wild pigs (Artiodactyla: Suidae) in the Philippines

Amblyomma anicornuta n. sp. (Acari: Ixodidae) is described based on adults and nymphs ex deer (Artiodactyla: Cervidae) and wild pigs (Artiodactyla: Suidae) from Luzon, Philippines. Adults of A. anicornuta n. sp. are similar to those of several Asian and Australasian species of Amblyomma Koch, 1844 with a 4/4 dental formula on the hypostome but can be distinguished by the colouration and pattern of punctations on the conscutum in the male and scutum in the female, the absence of a marginal groove on the conscutum in the male, the possession of long, thick, prominent setae on the alloscutum in the female, projections on anal valves and sclerotised ring around them in the male, a large median sclerite ventrally in the male, as well by the shape of the genital aperture in the female and the size and shape of spurs on coxae I–IV in both sexes. The nymph of A. anicornuta n. sp. is somewhat similar to that of A. babirussae Schulze, 1933 and A. geoemydae (Cantor, 1847) but can be distinguished by the colouration pattern on the scutum, the presence of dorsal cornua and the size of the spurs on coxae I–IV.     

Fine Structure of the Esophagus of Males of Sarisodera hydrophila (Heteroderoidea)

The fine structure of the esophagus, including procorpus, metacorpus, isthmus, gland lobe, and esophago-intestinal junction, is examined in males of Sarisodera hydrophila. A cuticle-lined lumen extends most of the length of the esophagus, broadens to form a pump chamber in the metacorpus, and posteriorly is continuous with junctional complexes among four esophago-intestinal cells. These four cells are partially enveloped by the gland lobe which basically consists of three gland cells, one dorsal and two subventral. Each gland cell has an anterior process which opens into the lumen of the esophagus through a cuticle-lined duct. The dorsal gland joins the lumen in the anterior portion of the procorpus, whereas ducts of the subventral glands terminate at the base of the metacorpus pump chamber. The subventral glands are predominant in the posterior portion of the gland lobe and are partially ensheathed by a narrow portion of the dorsal gland which extends to within 5 μm of the posterior terminus of the gland lobe. Contents of the dorsal gland include primarily electron dense granules, although rough endoplasmic reticulum (RER) is predominant posteriorly. Secretory granules within the subventral glands vary in morphology and are evenly distributed throughout the two ceils among other organelles, including RER and a large Golgi apparatus. Innervation of the esophagus includes nerve processes which originate from several perikaryons (cell bodies) located in the anterior portion of the gland lobe. The esophagus of males of S. hydrophila is compared with that of other Heteroderoidea, Heterodera glycines and Meloidogyne incognita.     

小木蠹蛾性信息素分泌腺的位置及组织学

对小木蠹蛾Holcocerus insularis雌蛾性信息素分泌腺提取物的触角电位(EAG)、毛细管气相色谱 (GC) 的测定以及对腺体位置和形态结构的扫描电镜、透视电镜观察。结果表明,小木蠹蛾性信息素分泌腺是一个由节间膜特化而成的上皮结构,位于腹部末端8～9节之间,为一个可外翻的腹褶,表面分布着饱满的锥形体。羽化后2天未交尾的雌蛾腺体细胞呈单层排列,腹面中央由密集的柱形细胞组成,向两侧延伸至背部,细胞由柱形逐渐变为扁平形,细胞核为椭圆形。细胞基底膜基褶较多,质膜上分布着微绒毛,并与内表皮连接,内表皮上有多层几丁质,细胞质中含有空泡、线粒体、脂质粒及光面内质网。     

Ultrastructural studies and Na+,K+-ATPase immunolocalization in the antennal urinary glands of the lobster Homarus gammarus (Crustacea, Decapoda).

Unlike in crustacean freshwater species, the structure and ultrastructure of the excretory antennal gland is poorly documented in marine species. The general organization and ultrastructure of the cells and the localization of Na(+),K(+)-ATPase were examined in the antennal gland of the adult lobster Homarus gammarus. Each gland is composed of a centrally located coelomosac surrounded ventrally by a labyrinth divided into two parts (I and II) and dorsally by a voluminous bladder. There is no differentiated nephridal tubule between them. The labyrinth and bladder cells have in common a number of ultrastructural cytological features, including basal membrane infoldings associated with mitochondria, apical microvilli, and cytoplasmic extrusions, and a cytoplasm packed with numerous vacuoles, vesicles, lysosome-like bodies, and swollen mitochondria. Each type of cell also presents distinctive characters. Na(+),K(+)-ATPase was detected through immunofluorescence in the basal part of the cells of the labyrinth and in the bladder cells with an increasing immunostaining from labyrinth I to the bladder. No immunoreactivity was detected in the coelomosac. The cells of the labyrinth and of the bladder present morphological and enzymatic features of ionocytes. The antennal glands of the lobster thus possess active ion exchanges capabilities.     

Gross morphology,histology, and ultrastructure of the alimentary system of Ricinulei (Arachnida) with emphasis on functional and phylogenetic implications

Ricinuleid functional mouthparts are the cucullus, the chelicerae, the pedipalps, and the labrum. These structures are movably jointed to the rest of the prosoma, most likely protruded upon hydrostatic hemolymph pressure and retracted by prosomal muscles. Seta‐like protrusions from the labrum and the pedipalpal coxae form a sieve‐like filter inside the preoral cavity and the mouth. Although the tip of the labrum can be elevated upon muscle constriction, ingestion of large, solid food particles is unlikely. The mouth has a crescent‐shaped cross section. The cuticle‐lined, also crescent‐shaped pharynx is equipped with a large dilator muscle but lacks antagonistic constrictor muscles. It represents a precerebral sucking pump. The triangular to Y‐shaped, cuticle‐lined esophagus is equipped with constrictor and dilator muscles. Its posterior part represents a postcerebral sucking pump. Four blind ending diverticula ramify from the anterior prosomal part of the entodermal midgut tube. Two of these diverticula remain inside the prosoma and form few short branches. The other two extend through the pedicel into the opisthosoma and ramify and coil there. A stercoral pocket protrudes ventrally out of the midgut tube. The most distal part of the midgut tube is modified into a contractile rectal gland. Its secretions may have defensive or physiological functions. A short anal atrium is formed by the cuticle‐lined ectodermal hindgut which opens at the end of the three‐segmented metasoma. The telescoping segments of the metasoma are protruded by hemolymph pressure and retracted by muscles. J. Morphol., 2011. © 2010 Wiley‐Liss, Inc.     

An unusual new species of the genus Brachypalpus Macquart (Diptera: Syrphidae) from Eastern Asia

Brachypalpus (Brachypalpus) longifacies sp. nov. is described and illustrated from Eastern Asia (Russian Far East and Japan). It differs from other species of the nominative subgenus by several unusual characters, i.e. face in profile weakly convex dorsally and concave ventrally, antennae very elongated, and abdomen with reddish transversal maculae on 2nd tergum (male) or 2nd and 3rd terga (female). A key is given for known species of the subgenus Brachypalpus.LSID: urn:lsid:zoobank.org:pub:634CB6E2-B2C1-40EC-8811-BF3DD4BDE69A