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.     

Differentiation of subspecies of the polymorphic species Hyalomma marginatum (Acari: Ixodidae) based on immature stages

Study of morphological characters to identify the subspecies of Hyalomma marginatum immature stages is based on material collected throughout all the geographical range of the species. As it was found, the discrimination of subspecies of H. marginatum immature stages needs a complex use of structural and morphometrical characters. Only H. m. marginatum larvae and H. m. isaaci nymphs may be easily differentiated from other subspecies based on the structural (qualitative) characters. Besides, morphometric (quantitative) characters should be used only in combinations for identification of the subspecies. In regard to structural characters of larvae, it was found that the shape and size of coxal spurs of H. marginatum allow differentiating this subspecies from the others (Fig. 3, 5, 6). Based on morphometrical characters of larvae, the following characteristic features of subspecies have been found: in H. m. marginatum, the capitulum is wide, the palpi, hypostome and genua I are short and narrow; in H. m. turanicum, the capitulum is narrow, the palpi are short and narrow, the hypostome is short and wide, the genua I are long and narrow; in H. m. rufipes, the scutum is large, the capitulum is wide, the palpi are long and narrow, the hypostome and genua I are long and wide; in H. m. isaaci, the scutum is small, the capitulum is narrow, the palpi and hypostome are long and narrow, the genua I are short and narrow. Among structural characters of nymph, several discriminative features of subspecies have been found. The shape of the scutum in H. m. isaaci (Fig. 2, 2) clearly differentiates this subspecies from the others (Fig. 2, 1). In H. m. marginatum, the setae of alloscutum as a rule have bluntly rounded apices (Fig. 1, 2), while in the other subspecies these setae are more tapering apically (Fig. 1, 1). The shape of spiracular plates is rather variable within the species, but in H. m. marginatum and H. m. isaaci (Fig. 1, 3) the plates are larger and more perforated than in H. m. rufipes and H. m. turanicum (Fig. 1, 4). In H. m. isaaci, the spurs of coxae I are narrower than in other subspecies (Fig. 1, 8). Based on morphometrical characters of nymphs, the following discriminative features of subspecies have been found: in H. m. marginatum, the capitulum is wide, the palpi are short and wide; in H. m. turanicum, the capitulum is narrow, the palpi are long and narrow; in H. m. rufipes, the scutum is wide, the capitulum is narrow, the palpi are long and narrow, the hypostome is long; in H. m. isaaci, the scutum is long and narrow, the capitulum is wide, the palpi are short and wide, the hypostome is short.     

The nymph of Anisagrion Selys 1876, based on the discovery of A. inornatum (Selys, 1876) in Ecuador (Odonata: Coenagrionidae)

The final instar nymph of Anisagrion inornatum is described and illustrated based on five specimens (one reared) from southern Ecuador. It is the first to be discovered for the genus. The nymph of Anisagrion inornatum differs from its closest relative, Apanisagrion lais, by: (1) antenna shorter in relation to head length (ratio 1.35 in An. inornatum vs 1.55 in Ap. lais); (2) fewer palpal and premental setae (5 palpal and 4 or 5 premental setae in An. inornatum vs 6?C8 palpal and 5?C8 premental setae in Ap. lais); (3) venter of S3?CS8 with medial dark stripe. The nymphs were found in a slow shallow seep overgrown with emergent wetland plants.     

Comparative study of the sensory system in gamasid mites Rhinonyssus rhinolethrum,Rh. subrhinolethrum and Ptilonyssus motacillae (Mesostigmata: Gamasina: Rhinonyssidae), parasites in the nasal cavity of birds

Sensillae of the tarsal receptor complex, palpal organ, and body chaetom were examined by means of scanning electron microscopy in three endoparasitic gamasid mites: Rhinonyssus rhinolethrum, Rh. subrhinolethrum and Ptilonyssus motacillae, the parasites of Anser albifrons, Anas crecca, and Motacilla alba, respectively. In the tarsal sensory complex, the scale of reduction of the olfactory sensilla reflects the adaptation of gamasid mites to cavernous parasitism. The topography of this sensilla is specific at generic and species taxonomic levels. In the palpal sensory organ, the number and scale of reduction of two main sensilla types depend on peculiarities of places of blood-sucking.     

中国新纪录科条顿螨科及其一新种记述(蜱螨亚纲,水螨群,腺水螨总科)

记述了中国新纪录科条顿螨科Teutoniidae Koenike．1910条顿螨属Teutonia亚条顿螨亚属Subteutonia及其1新种多毛条顿螨Teutonia(Subteutonia)piloseta sp．nov．。新种须肢羽状栓毛及栓毛数量以及呈半包围状态的EpⅣ可以将之与其他亚条顿螨亚属种类区别。文中对其腺毛和眼毛的体位特征做了详细描述。     

Description of a new argasid tick (Acari: Ixodida) from bat caves in Brazilian Amazon

Nothoaspis amazoniensis n. sp. (Acari: Ixodida: Argasidae) is described from adult and immature ticks (nymph II, nymph I, larva) collected from bat caves in the Brazilian Amazon. Also, 16S rDNA sequences are provided. The diagnostic characters for adults are the presence of false shield or nothoaspis, an anteriorly projecting hood covering the capitulum, a medial extension of palpal article I (flaps), genital plate extending from coxa I to IV, absence of 2 setae on the internal margin of the flaps, a minute hypostome without denticles, presence of a central pore in the base of hypostome, and a reticulate surface pattern on the posterior half of the nothoaspis in males. The nymph II stage is characterized by a hood that is small in relation to the capitulum, short coxal setae, palpal flaps lacking setae on the internal margin, long hypostome, pointed with dentition 4/4 apically, and the anterior half of the body is covered by a cell-like configuration. Nymph I stage is characterized by a hood, small in relation to the capitulum, dorsum of the body covered by a cell-like configuration, venter integument covered by a cell-like configuration, and hypostome dentition 4/4 with apices that are "V"-shaped. Diagnostic characters of the larvae are the number and size of dorsal setae, and the shape of scutum and hypostome. The new species appears to have a life cycle with a larva that feeds on bats, a non-feeding nymphal stage (nymph I), a feeding nymphal stage (nymph II), and adults that probably represent non-feeding stages.     

青海省新恙螨属一新种(蜱螨亚纲：恙螨科)

记述新恙螨属NeotrombiculaHirst ,192 5一新种 ,拟旱獭新恙螨Neotrombiculaparamarmotaesp .nov .,模式标本采自民和县的松田鼠PitymysireneThomas,1911体上。标本存放在青海省地方病防治研究所。量度单位均为 μm。     

First evidence of neurons in the male copulatory organ of a spider (Arachnida,Araneae)

Spider males have evolved a remarkable way of transferring sperm by using a modified part of their pedipalps, the so-called palpal organ. The palpal organ is ontogenetically derived from tarsal claws; however, no nerves, sensory organs or muscles have been detected in the palpal bulb so far, suggesting that the spider male copulatory organ is numb and sensorily blind. Here, we document the presence of neurons and a nerve inside the male palpal organ of a spider for the first time. Several neurons that are located in the embolus are attached to the surrounding cuticle where stresses and strains lead to a deformation (stretching) of the palpal cuticle on a local scale, suggesting a putative proprioreceptive function. Consequently, the male copulatory organ of this species is not just a numb structure but likely able to directly perceive sensory input during sperm transfer. In addition, we identified two glands in the palpal organ, one of which is located in the embolus (embolus gland). The embolus gland appears to be directly innervated, which could allow for rapid modulation of secretory activity. Thus, we hypothesize that the transferred seminal fluid can be modulated to influence female processes.     

Antennular sensilla of the brine shrimp, Artemia salina.

1. Scanning electron microscopy was used to characterize the external morphology of setae found on the antennules of adults and nauplii of the brine shrimp, Artemia salina (L.). The permeability of the antennular setae was studied by means of Slifer's crystal violet method. 2. Each antennule of an adult brine shrimp possessed a terminal cluster of sensory setae. Within a cluster there were two morphologically distinct kinds of sensilla, here designated type 1 and type 2. Three type 1 sensilla were observed on every antennule examined. The number of type 2 sensilla per antennule was usually four or five. 3. Type 1 sensilla of adults were 43 to 80 micrometer long and simple in external morphology. They were widest at the base, decreased in diameter gradually, and terminated as a finely tapered tip. No pores were resolved by scanning electron microscopy. 4. Type 2 sensilla of adults were shorter (shaft length, 12 to 23 micrometer) and displayed a single pore at the tip (average pore diameter, 0.4 micrometer). In thin section they were seen to possess a distinctive articular specialization of the cuticle at the base of the seta. 5. Dye penetration experiments indicated that type 2 sensilla were permeable to aqueous crystal violet, whereas type 1 sensilla were not. 6. The antennular setae of nauplii resembled type 1 sensilla in general shape, in being impermeable to crystal violet, and in lacking a terminal pore and basal articular specialization. Moreover, a total of three setae was normally present on each naupliar antennule, and the same number of type 1 sensilla was found on each adult antennule examined. If the three naupliar setae represent a developmental stage in the formation of three adult sensilla, available observations suggest that the larval setae are developmentally related to type 1, rather than to type 2 adult sensilla.     

Morphological and molecular differentiation of Clinostomum complanatum and Clinostomum marginatum (Digenea: Clinostomidae) metacercariae and adults

The separation of Clinostomum complanatum Rudolphi, 1814 and Clinostomum marginatum Rudolphi, 1819 has long been unclear. Recent data confirm the validity of the junior species, C. marginatum , by ～ 1% differences in its 18S rDNA sequences. We collected adults and metacercariae of C. complanatum and C. marginatum and found reliable morphological differences in the genital complex at both developmental stages. In addition, we identified basic morphometrics (distance between suckers, body width) in metacercariae that may be useful for discriminating the species. The morphological differences were supported by the comparison of sequences of internal transcribed spacers of ribosomal DNA and of the mitochondrial gene cytochrome c oxidase I (COI) from 39 specimens. In 36 specimens, the average divergence between the species was 7.3% in ITS and 19.4% in COI sequences. Two specimens from North America and 1 from Europe had sequences that did not allow them to be clearly allied with either species.     

Ultrastructure of the maxillary organ of Scutigera coleoptrata (Chilopoda, Notostigmophora): description of a multifunctional head organ

The maxillary organ of Scutigera coleoptrata was investigated using light microscopy, electron microscopy, and maceration techniques. Additionally, we compared the maxillary organ of S. coleoptrata with those of two other notostigmophoran centipedes, Parascutigera festiva and Allothereua maculata, using SEM. The maxillary organ is located inside the posterior coxal lobes of the first maxillae and extends posteriorly as sac-like pouches. The narrow epidermis of the maxillae is differentiated to form the epithelium of the maxillary organ. Two types of epithelia are distinguishable: a simple cuboidal epithelium of different height and differentiation (types I, II, IV) and a pseudostratified columnar epithelium (type III). These epithelia are covered by a highly specialized cuticle. The pseudostratified epithelium is the most prominent feature of the maxillary organ. It is covered with hundreds of setae, protruding deep into the maxillary organ. Two different types of setae can be distinguished, filiform and fusiform. The maxillary organ communicates with the oral cavity, the maxillary organ gland, the maxillary nephridium, and with a large number of epidermal glands that secrete into the maxillary organ. Epithelium III allows the extension of the maxillary organ when its pouches are filled with secretion. The maxillary organ is a complex multifunctional organ. The organ probably stores excretion from the maxillary nephridia and secretory fluid from the maxillary organ gland and other epidermal glands. The fluid is primarily required as preening fluid. The ammonia of the excretory fluid is thought to evaporate via the setae and the wide opening of the maxillary organ. It is likely that parts of the fluid can be reabsorbed by the animal via the oral cavity.     

A description of the female and larva of the relic species Ixodes ghilarovi (Ixodidae)

Ixodes (Exopalpiger) ghilarovi was found in 4 separated localities of the Great Caucasus at a height of 1000 to 2200 m above sea level. Female differs from palaearctic I. (Exopalpiger) trianguliceps in 4-4 pairs of setae of the anal valve, shape of scutum, longer setae of alloscutum, more round peritreme, correlation between the length of peritreme longitudinal diameter and the length of longitudinal diameter of the anal ring, presence of auricles and shape of palps. Larva differs from I. trianguliceps in longer setae of alloscutum, longer ventrolateral tooth of 1st palpal joint and longer medial tooth of coxae I.     

Comparative studies on the structure and adhesion of setae in G. gecko and G. swinhonis

Scanning electron microscopy (SEM) and histological techniques were used to observe and study the setae structures of two gecko species (G. gecko and G. swinhonis) and the relationships between these structures and the adhesive forces. The SEM results showed that the setae of these two species were densely distributed in an orderly fashion, and branched with curved tips. The setae of G. gecko had cluster structures, each cluster containing 4-6 setae whose terminal branches curved towards the center of the toes at ~ 10o, the tips of the branches like spatulae and densely arrayed at an interval of less than 0.2―0.3 μm. On the contrary, the branch tips in the setae of G. swinhonis were curled, and the terminal parts of setae curved towards the center of the toes at various angles. Usually the setae of these gecko species branch twice at the top at intervals greater than that of G. gecko. The histological observation found that inside the setae of these two species there were plenty of unevenly distributed contents, such as epithelia, fat cells, pigmental cells and muscle tissue, but no gland cells existed. The results of functional experiments suggested that modifying the structure of gecko's setae could reduce its adhesive ability dramatically, demonstrating the positive correlation between the structure of the gecko's setae and its adhesive ability. The above results provide important information in designing bio-mimic setae and bio-gecko robots.     

Role of maxilla 2 and its setae during feeding in the shrimp Palaemon adspersus (Crustacea: Decapoda)

The movements of the basis of maxilla 2 in Palaemon adspersus were examined using macro-video recordings, and the morphology of its setae was examined using both scanning and transmission electron microscopy. The basis of maxilla 2 performs stereotypical movements in the latero-medial plane and gently touches the food with a frequency of 3-5 Hz. The medial rim of the basis of maxilla 2 carries three types of seta. Type 1 is serrate, type 2 and 3 are serrulate, and type 2 has a prominent terminal pore. Type 2 is innervated by 18-25 sensory cells whose cilia protrude through the terminal pore and are in direct contact with the external environment. The structure of type 2 setae indicates that they are mainly gustatory, although still bimodal due to their innervation by presumed chemosensory and mechanosensory neurons. Distally, the three types of setae have a complex arrangement of the cuticle involving water-filled canals, which may serve to improve flexibility. Type 1 and 3 setae have fewer sensory cells (4-9) but probably also have a bimodal sensory function. The function of type 1 setae is probably to protect type 2 setae, while type 3 setae might serve to groom the ventral side of the basis of maxilla 1.     

The design of the fly adhesive pad: distal tenent setae are adapted to the delivery of an adhesive secretion

Flies (Brachycera) have adhesive pads called pulvilli at the terminal tarsomere. The pulvilli are covered by tenent setae, sometimes termed tenent hairs, which serve to increase the actual area of attachment to the surface. By using transmission and scanning electron microscopy it is shown that proximal and distal tenent setae have different ultrastructures. The design of distal adhesive setae is adapted for the release of adhesive substances close to the area of contact. It is concluded that secretion injection is precisely targeted under the distal tip of a single seta.     

The Structure and Evolution of the Apical Sensory Zone Structures in the Maxillary and Labial Palps of Caddisflies (Trichoptera)

A comparative morphological study of the apical regions of palps in Trichoptera from different evolutionary lines of the order was carried out, and a comparison was made with representatives of Lepidoptera and Mecoptera. Light and scanning electron microscopy methods were used to study the structure of palpal apices in 81 species of the order Trichoptera, 6 of Lepidoptera, and 2 species of Mecoptera. As a result, 11 types of sensilla were identified on the terminal palpal segments, and highly differentiated apical sensory zones with thick short basiconic sensilla were found on the maxillary and labial palps. The presence of an apical sensory zone in caddisflies and related orders is recognized as a plesiomorphic character.     

Bacteria associated with tegument of Clinostomum marginatum (Digenea)

Adults of Clinostomum marginatum freshly collected from a heron, Ardea herodias, were examined using transmission electron microscopy. Specimens from the mouth of the bird were encrusted with bacteria that were not removed by washing unless the saline contained antibiotics. There was no evidence that the attached bacteria were damaging to the trematode tegument. Three species of Gram-negative bacteria were isolated from the worm surfaces and identified; Achromobacter sp. was present in pure culture on 4 of 6 original cultures and in mixed culture with Edwardsiella tarda and Enterobacter agglomerans in 2 cultures. These species and 3 unidentified species of bacteria were isolated from the oral epithelium of the heron. Microorganisms were not seen attached to the surfaces of worms recovered from the esophagus. Because E. tarda and E. agglomerans were the only species isolated from the heron esophagus, the intimate bacterial-worm association in the heron mouth may be due specifically to Achromobacter sp.     

Discrimination of subspecies in a polymorphic species Hyalomma marginatum (Acari, Ixodidae) based on adult stage

Morphological characteristics allowing discriminating adult stages of four subspecies of Hyalomma marginatum (H. m. marginatum, H. m. turanicum, H. m. rufipes and H. m. isaaci) are displayed. The subspecies status of all named forms is confirmed. The main discriminating characters for adults of these subspecies are peculiarities of scutal or conscutal punctations and a shape of the dorsal tale of spiracular plates (Fig. 1, 1-4; 2, 4-7; 4, 1, 2; 5, 1, 2, 6, 5-8). Nevertheless, there are a number of facts, which support only the subspecific rank of these taxa. In Turkmenistan, there is a zone inhabited by forms, adult stages of which are morphologically intermedial between H. m. marginatum and H. m. turanicum. A zone of intermedial forms between H. m. turanicum and H. m. rufipes exists in Arabian Peninsula (Hoogstraal e. a., 1981). An absence of clear discriminative characters between immatures of H. m. marginatum, H. m. turanicum and H. m. rufipes also confirms the subspecies level of these taxa. H. m. isaaci is the most differentiated subspecies. It is difficult to estimate relationships between the latter subspecies and H. m. turanicum because of a deficit of materials. However, clear morphological differences of H. m. isaaci immature stages from other subspecies were noticed (Apanaskevich, 2003). Therefore, it is quite probable that H. m. isaaci might deserve the species rank. Further analysis of relationships between subspecies of H. marginatum needs additional materials represented by all stages from zones containing intermedial forms between recently recognized subspecies.