External micromorphology of the frons plate and its adjacent areas in workers of the oriental hornet

The micromorphology of the frons and the adjacent regions in young workers (1–24 hr of age) of the Oriental hornet Vespa orientalis and some adult worker hornets is described. The young workers still lack globular secretions at the bases of the setae. Such secretions do occur at the bases of the setae in the adult workers and are composed mainly of the elements Si, Al, S, Mg, Ca, Cl, and Fe. Contiguous with each of the ocelli is a gland that also secretes minerals. Young workers usually have a relatively large concentration of Ca in the glands behind the paired ocelli. The gland associated with the median anterior ocellus opens by an elongated sutura coronalis in the frons and contains various elements, predominantly Si, but also Ca. The setae (hairs) on the frons are arranged in concentric circles around each of the ocelli; they are long in the upper part of the frons but shorten gradually toward the tip of the frons. The tip lacks hair, but the cuticle bears elevated scales that project as cuticular protuberences. It appears that the ocelli and their associated glands, and the entire frons plate with its hairs and glands at the bases of the hairs in this region, comprise an equilibrium “organ” that senses changes in gravity. © 1992 Wiley-Liss, Inc.     

Descriptions of the previously unknown xylobiont larva and pupa of <Emphasis Type="Italic">Atypophthalmus inustus</Emphasis> (Diptera,Limoniidae)

The larval and pupal morphology of Atypophthalmus inustus (Meigen, 1818) are described for the first time. The main diagnostic characters are the following: head capsule massive, frons with 3 short terminal projections, hypostomium with 11 teeth and long narrow split, hypopharynx and labium with well-developed conical teeth, stigmal area with 2 long ventral pigmented spots.     

ALEXANDRIUM SATOANUM SP. NOV. (DINOPHYCEAE) FROM MATOYA BAY,CENTRAL JAPAN1

The gonyaulacoid dinofiagellate Alexandrium satoanum Yuki et Fukuyo sp. nov. is described from Matoya Bay, Pacific coast of central Japan. The species is distinctive in its conical epitheca with almost straight sides and dorsal concavity of the hypotheca. The plate formula is Po, pc, 4′, 6″, 6c, 10s, 5″″, and 2″″, including two accessory plates inside the sulcus. The apical pore plate is triangular and possesses an anterior attachment pore at the right margin. The first apical plate does not make contact with the apical pore plate and lacks a ventral pore. A posterior attachment pore lies at the center of the posterior sulcal plate. In Matoya Bay, vegetative cells occur as solitary cells or sometimes in pairs during late spring and early summer in low concentrations. In connection with this study, the following new combination is proposed: Alexandrium pseudogonyaulax (Biecheler) Horiguchi ex Yuki et Fukuyo comb. nov.     

Morphology of the archaellar motor and associated cytoplasmic cone in Thermococcus kodakaraensis

Archaeal swimming motility is driven by archaella: rotary motors attached to long extracellular filaments. The structure of these motors, and particularly how they are anchored in the absence of a peptidoglycan cell wall, is unknown. Here, we use electron cryotomography to visualize the archaellar basal body in vivo in Thermococcus kodakaraensis KOD1. Compared to the homologous bacterial type IV pilus (T4P), we observe structural similarities as well as several unique features. While the position of the cytoplasmic ATPase appears conserved, it is not braced by linkages that extend upward through the cell envelope as in the T4P, but rather by cytoplasmic components that attach it to a large conical frustum up to 500 nm in diameter at its base. In addition to anchoring the lophotrichous bundle of archaella, the conical frustum associates with chemosensory arrays and ribosome‐excluding material and may function as a polar organizing center for the coccoid cells.     

The presence of statocysts and statoliths in social wasps (Hymenoptera, Vespinae)

Static sense organs composed of a hollow statocyst surrounded by sensory hairs and containing aggregate bodies (statoliths) have been detected in various species of Vespinae. On the frons in the groove traversing its center (the frontal groove) there is a deep pit and around it a membrane enclosing a cyst-like sac. In Vespa orientalis there are silicon (Si) and calcium (Ca)-containing aggregates inside the pit arranged in morula-like fashion, and in V. crabro, there are similar aggregates arranged in an ear-like shape. In general this sensillar organ resembles the statocyst located on the bases of the antennules in decapod crustaceans.     

Histological structure of the female gonads and ovipositor of the European bitterling,Rhodeus amarus (Bloch, 1782) (Cyprinidae: Acheilognathinae)

We investigated the histological structure of the female gonads and ovipositor of the European bitterling, Rhodeus amarus. The base of the ovipositor was formed by the conical organ or ‘eminence’. Based on the structure of the conical organ, including a special distribution of collagenous and muscular fibrils, a well‐developed vascular system and numerous scyphoid mucous cells in the internal epithelium, this organ was used for temporary storage of oocytes during the spawning period and for their movement along the ovipositor. An extensive network of blood vessels, muscular fibrils and numerous collagenous fibrils in the connective tissue of the ovipositor may make a functional contribution to the ovipositor by making it firmer during egg laying. Mucous cells were detected in the medial and distal regions of the ovipositor, which may play a role in facilitating insertion of the ovipositor into the exhalant siphon of a mussel during oviposition. European bitterling are batch spawners, and the female spawns eggs in clutches at intervals during the breeding season, which were visible as three distinct cohorts of oocytes in the ovary.     

A new genus of praying mantis,Chlorocalis n. gen., with two new species from the Greater Mekong region (Mantodea: Mantidae)

A new genus of praying mantis is described, Chlorocalis n. gen., with two species, C. maternaschulzei n. sp. and C. prasina n. sp. from the Greater Mekong Region. Chlorocalis is placed in Mantidae and can be immediately recognized by the presence of dark brown (male) or yellow-whitish (female) oblique stripes on the forewings, a large conical bulge on the clypeus, two large conical bulges on either side of the inferior margin of the lower frons, and the male genitalia with two distal processes on the ventral phallomere. Chlorocalis maternaschulzei is a widespread lowland species with records as west as Nakhon Ratchasima Province, Thailand, and as east as mount Núi Chúa in southern Central Vietnam. We consider this species to be of Least Concern. In contrast, C. prasina is a narrow-range mountain endemic of the Vietnamese Central Highlands in the Annamite range and is assessed by us to be Vulnerable. The new findings demonstrate the still very poor knowledge on praying mantis species diversity in South-East Asia and the urgency to resolve this taxonomic deficiency in the face of biodiversity loss.     

Multifunctions of the upper lip and a ventral reflecting organ in a bioluminescent ostracod Vargula hilgendorfii (Müller, 1890)

Multifunctions of the upper lip in a bioluminescent myodocopid Vargula hilgendorfii were studied by video observation and histological method. The localization of luciferin and luciferase gland cells within the upper lip was partly successful. Two long protrusions of the upper lip, both of V. hilgendorfii and a non-luminescent species of the same family, immediately anterior to the mouth, were found to show very flexible movement especially while eating, as if smearing on the food surface a secretion from the protrusions (glands), which may support the hypothesized secretion of digestive enzymes from the upper lip. This hypothesis is further supported by the new finding of a pair of ducts which connect the basal part of the upper lip with the posterior digestive duct (stomach). Comparative studies of V. hilgendorfii with several sympatric non-luminescent species of the same family have also revealed that it has a characteristic reflecting organ immediately posterior to the anus. It is a conical small protrusion, as if dangling from the ventral edge of the abdomen at the apex of the cone. It is observable only in live specimens, when the furca, which is located outwardly to the organ, is sufficiently transparent. When illuminated, the reflecting organ reflects the distinct light. The diameter of the mirror (chemical composition provisionally analyzed) is about 6–8% of the carapace length. The organ develops from the very first stage of its ontogeny without reference to sex, which suggests that the function may be related to intraspecific signaling or predatory deterrence.     

Structure of the ovipositor and ovary and the features of reproduction in Amur bitterling <Emphasis Type="Italic">Rhodeus sericeus</Emphasis> (Cyprinidae: Acheilognatinae)

Biological characteristics of sexually mature individuals of Amur bitterling Rhodeus sericeus from the Amur River basin are described. Sexual maturity is reached in the first year of life in males and in the second year in females. The development of ovipositors is observed during sexual maturation of the females and their preparation to spawning. The base of the ovipositor is formed by the conical organ. Based on the structure of the conical organ, including a special distribution of collagenous and muscular fibrils, well developed blood system, and numerous mucous cells in the internal epithelial layer, this organ is used for temporal storage of oocytes during the spawning period and for their movement along the ovipositor. Owing to a well developed net of blood vessels, presence of muscular wall, and numerous collagenous fibrils in the connective tissue, a stable position of the ovipositor is reached during the spawning. Based on secretion of numerous mucous cells of the external epithelial layer of the ovipositor, this organ is inserted into the excretory siphon of the mollusk during egg deposition. The spawning in Amur bitterling is in batches, and it is multiple. The oocytes of three generations can be seen in the ovary. The oocyte possesses a thin zona radiata. Based on the presence of a dense gelatinous layer in the basal part of the chorion, the egg is attached to the internal hemibranches of bivalves. The observations of free embryos of Amur bitterling in the left internal hemibranches of bivalves Sinanodonta likharevi, Nodularia amurensis, N. schrencki, and N. middendorffi show that the symbiotic relationships can be characterized as obligate.     

On the Distribution of the Crustacean Dorsal Organ

An oval, dorsal organ, variously bearing four minute pits around a central pore and/or encircled by a cuticular border, has been reported for the cephalic region of various groups of living and fossil crustaceans. Although varying somewhat in location and in size, the organ appears basically uniform in organization in at least two of the major crustacean taxa: Branchiopoda (especially Laevicaudata) and Malacostraca (Decapoda and Syncarida). Little is known about its ultrastructure and function in various groups, and it is likely that the term ‘dorsal organ’ also has been applied to several nonhomologous structures. In particular, the embryonic dorsal organ, reviewed recently by Fioroni (Fioroni, P. 1980.—Zoologische Jahrbücher (Anatomie) 104: 425–465) and apparently functioning in nutrition and ecdysis, is not the topic of this paper; that organ is similar in name and location only and appears in embryonic uniramians, chelicerates, and crustaceans. The function of the dorsal organ in branchiopods is in ion regulation, possibly a secondary modification of the original function in marine crustaceans, which is unknown. In larval decapods, the organ probably functions as a chemo- or mechano-receptor. We review the known occurrence of the crustacean dorsal organ, describe the similarities and differences in structure in various taxa, and review the competing hypotheses concerning its function. Phylogenetic implications are discussed.     

Morphology and ultrastructure of the organ of Bellonci in the marine amphipod Gammarus setosus

The three-dimensional structure of the organ of Bellonci in the marine amphipod Gammarus setosus and the relationship between its sensory cells and concretion are described using light, transmission, and scanning electron microscopy, with chemical treatment for cell lysis, calcium chelation, glycogen staining, and lanthanum labelling. The organ is encapsulated and has three units called fuselli. Each is enclosed by two fusellar cells which generate and release calcium granule strands into the cores of the fusellar concretions, which are united in the center of the organ. The surface of each fusellus is traversed by spiral dendrites entering dorsally and ending ventrally. The spiral dendrites arise from sensory neurons contained in a palm-shaped ganglion in the center of the capsule, beyond which they are twisted like a rope before reaching the concretion. The spiral dendrites are linked in pairs by gap and tight junctions and each gives origin to two pairs of 9+0 sensory cilia 30 μm apart. The ciliary distal segments give rise to long tubules which are in contact with the calcium granule strands. The ciliary proximal segments are expanded by many long mitochondria which interdigitate with the branched striated ciliary rootlets. The concretion is suspended in the capsule cavity by axons originating from four neurons of a remote mechanoreceptor. The structure of the organ suggests that it is a sensory organ involved in the reception and integration of a variety of stimuli.     

Microscopic anatomy and fine structure of the skeleton-heart-kidney complex in <Emphasis Type="Italic">Saccoglossus mereschkowskii</Emphasis> (Hemichordata,Enteropneusta): 1. Stalk skeleton

This is the first paper of the series devoted to the microscopic anatomy and fine structure of the skeleton-heart-kidney complex in the acorn worm Saccoglossus mereschkowskii Wagner 1885. The skeleton of S. mereschkowskii consists of the unpaired anterior plate (lamina imparis) and two posterior horns (corni). The anterior plate bears a pair of lateral wings (alae laterales), the midventral keel (carina ventralis), the central fossa (fossa centralis) with the bordering ridge (crista circumflexa fossae centralis), two symmetrical supporting saucers (subiculi), and the conical rostrum (rostrum). The skeleton is an accretion (overgrowth) of the basal lamina between the epidermis and the endodermal epithelium of the buccal diverticulum (in the anterior part) and between the endodermal epithelia of the buccal diverticulum and the gut (in the posterior part) and consists of collagen fibers, mostly longitudinal. In all representatives of the Enteropneusta studied to date, the skeleton is a wishbone-like structure with the unpaired anterior plate and paired posterior horns, but its components widely vary in shape between species. In the family Harrimaniidae, the horns are long, and the anterior plate is rod-shaped. In the Ptychoderidae, the horns are short, and the anterior plate is rectangular. In the Spengelidae, the skeleton has an intermediate shape.     

Unique two-photoreceptor scanning eye of the nematode Mermis nigrescens

A single eye is present in females of the nematode Mermis nigrescens. A pigment cup occupies the entire cross section near the anterior tip of the worm, and the curved cuticle at the tip becomes a cornea. The shading pigment is hemoglobin instead of melanin. The eye has been shown to provide a positive phototaxis utilizing a scanning mechanism; however, the eye's structure has not been sufficiently described. Here, we provide a reconstruction of the eye on the basis of light and electron microscopy of serial sections. Hemoglobin crystals are densely packed in the cytoplasm of expanded hypodermal cells, forming the cylindrical shadowing structure. The two putative photoreceptors are found laterally within the transparent conical center of this structure where they would be exposed to light from different anterior fields of view. Each consists of a multilamellar sensory process formed by one of the dendrites in each of the two amphidial sensory nerve bundles that pass through the center. Multilamellar processes are also found in the same location in immature adult females and fourth stage juvenile females, which lack the shadowing pigment and exhibit a weak negative phototaxis. The unique structure of the pigment cup eye is discussed in terms of optical function, phototaxis mechanism, eye nomenclature, and evolution.     

Relationships of the Musca domestica subspecies calleva and curviforceps (Diptera: Muscidae) in Rhodesia

Abstract. Field investigations on Musca domestica houseflies in Rhodesia demonstrate a greater degree of contact than previously reported between domestic M. d. curviforceps and feral M. d. calleva at their habitat interface. There was no evidence of any seasonal disappearance of hybrid flies; stable, intermediate, largely domestic populations are a feature of areas of sympatry. The existence of almost pure calleva feral populations in these areas was verified, though a slight degree of introgression with curviforceps was demonstrated for the first time. Gene-flow between the subspecies was studied and a new explanation for the one-way gene-flow, based on habitat choice of hybrid flies, is advanced.
Frons ratio, widely used in distinguishing different forms of housefly, showed serious limitations as a taxonomic character. The ratio, intended as a size-adjusted measure of frons width, is not independent of size, and frons width and head width (shown to be a good measure of size) are at best weakly correlated. It was confirmed that the frons width of male calleva × curviforceps hybrids is stabilized at the fronJ width characteristic of curviforceps although laboratory breeding results indicate that intermediate frons widths are to be expected. The stabilization is due to selection for broader frons width in the domestic habitat. The nature of the selection is explained, and evidence is produced regarding its basis.     

A new type of somatosensory organ in the nasolabial skin of the dog

A new morphological type of somatosensory organ is described. It is found in the glabrous skin of the dog nose (rhinarium or planum nasale) and situated in dermis papillae. The otherwise thick epidermis forms a thin window above the organ. There are only a few layers of keratinocytes in the window and the corneocytes are much thinner than elsewhere. The organ consists of highly branching cells that wrap naked nerve endings emanating from myelinated nerve fibers originating in the outer dermal nerve plexus. The structure entirely fills the top of the dermal papilla. The intercellular spaces of the organ and its surroundings are occupied by an extended areolar basal lamina.     

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.     

Structure and function of the frontal pit of Lipoptena spp. (Diptera: Hippoboscidae)

Scanning electron microscopy and histological techniques were used to study the structure and possible function of the frontal pit present in the frons of Lipoptena annalizeae. In the adult fly the opening leads into a closed sclerotized tube (torma) within a sclerite (fulcrum), to which the cibarial pump muscles are attached enabling the retraction of the proboscis. A method for softening the heads of Lipoptena for histological studies is also described. © 1994 Wiley-Liss, Inc.     

New information on cranial and dental features of the Triassic archosauriform reptile Euparkeria capensis

The course of the nasolacrimal duct, interdental plate morphology, and most details of tooth and denticle morphology have not previously been described in non–archosauriform reptilkes. Here I describe these details in the Triassic archosauriform Euparkeria capensis. The nasolacrimal canal opens orbitally via a pair of foramina between the lacrimal and prefrontal. The canal arches over the antorbital fenestra, as in archosaurs. The term ‘interdental unit’ is introduced for the unit composed of an interdental septum and its accompanying interdental plate. There is no demarcation between interdental plate and septum in E. capensis. The interdental units are heavily pitted on exposed surfaces. Like teeth, they are implanted in the dental groove and are separate from the surrounding bone and from each other. They are well positioned to serve as spacers between teeth, and to resist sagittal forces on teeth during prey capture. The teeth of E. capensis are labiolingually compressed, except for the nearly conical premaxillary teeth and mesialmost dentary tooth. Lateral teeth are serrated on mesial and distal keels. The denticles are low, rounded, and separated by grooves, and are slightly larger on the distal keel. Tooth morphology suggests carnivorous habits for Euparkeria.     

Show me your tenent setae and I tell you who you are – Telling the story of a neglected character complex with phylogenetic signals using Leiodidae (Coleoptera) as a case study

The tarsal setae in 97 species of Leiodidae and eight outgroups were examined using SEM imaging and dissections. Modified adhesive setae present in males are referred to as “male tenent setae” (MTS). In most cases, dilated tarsomeres were associated with MTS, which were always present on the protarsi and sometimes the mesotarsi. MTS are reported for the first time on the mesotarsi of Leptodirini and on the metatarsi in two genera of Sogdini. Contrary to reports in the literature, the reduction in the number of the MTS bearing mesotarsomeres is considered a derived condition. Both sexes of Leptinus (Platypsyllinae) have modified setae (referred to as tenent setae in the literature), probably related to their specialised association with mammals, and a patch of MTS was recognized for the first time among those modified setae among males. Four main types of MTS are recognised: (1) a plesiomorphic discoidal type that has a shaft with a round cross-section and maintains a similar diameter throughout its length until forming the expanded discoidal terminal plate; (2) a minidiscoidal type, similar to discoidal but with a relatively small terminal plate, found in Cholevinae; (3) a conical type, present in Leiodinae (excluding Estadiini) where the shaft increases in diameter until forming the terminal plate; and (4) a spatulate type, where an even wider terminal plate has a lateral projection, derived from the conical form and synapomorphic for the leiodine tribes Pseudoliodini, Scotocryptini, and possibly Agathidiini.     

POLLEN-FORAGING BEHAVIOR OF BOMBUS IN RELATION TO POLLINATION OF NOTOTRIBIC FLOWERS

Cinematographic records of the pollen-foraging behavior of six Bombus species on Linaria vulgaris, Lobelia siphilitica, and Antirrhinum majus revealed a generally uniform pattern of pollen deposition by the nototribic flowers on the frons and scutum of the foragers. A forward sweeping motion of the tarsal brushes of their middle legs removed some of this pollen which was transferred to the tibial corbicula of the hind legs. Some insects foraged in an inverted position. An analysis of 804 pollen samples from frons, scutum, and corbiculum of 331 from a total of 395 Bombus visitors, representing eight of the nine native species, on the three plants indicated a high proportion of proper pollen being collected in addition to 15 kinds of foreign pollen. The pollen-sweeping behavior of Bombus on nototribic flowers is suggested as an important means of pollen-foraging apart from its utility in insect grooming. Pollen-foraging insects are considered important pollinators of these nototribic flowers.