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.     

Tarsal sensory complex of the red chicken mite Dermanyssus gallinae (Acari: Dermanyssidae)

The tarsal sensory complex of the red chicken mite Dermanyssus gallinae is situated on dorsal surface of each fore leg near the claw. It comprises 28 sensilla of 5 morphological types: 4 SW-UP (single-wall upper-pore) (gustatory organs), 8 SW-WP (single-wall wall-pore) (olfactory organs), 8 DW-WP (double-wall wall-pore) of two subtypes (thermo-chemoreceptory organs), 6 NP-TB (no pore--tubular body) (tactile organs), and 2 reduced sensilla. No sex or stage dimorphism was revealed. Morphological data point to the fact that tarsal sensory complex of the red chicken mite is mainly an organ detecting temperature changes and olfactory stimula.     

Ultrastructure of the tarsal receptor complex in the gamasid mite Histionyssus criceti (Hirstionyssidae)

The main distant receptor organ of H. criceti, situated on the tarsus of each first leg, was studied by scanning and transmitting electron microscopy. The organ contains 6 types of sensilla, including 4 distant ones (two types of olfactory sensilla, differing in wall thickness, and 2 types of probable chemo-thermosensitive sensilla, possessing different double-walled hairs), and also taste organs of common structure and microchaeta. Cilia of all the sensilla contain 13 pairs of peripheral fibers. Comparative analysis of fine structure of distant sensilla in bloodsucking insects, ticks and mites made it possible to show, that blood-sucking gamasids and ticks possess similar number of homologous sensillar types, that formed on a common ground as the specific adaptation to blood-sucking.     

革螨跗感器的结构和功能

本文进一步研究了:④厩真厉螨截肢前后的爬行行为,表明第1对足其感觉功能;②用古拉广厉螨分别截各对足驱避反应的对比试验,见到只有当截去第1对足跗节时失去嗅觉功能,而截去第Ⅱ、Ⅲ、Ⅳ对足时,各组都仍有嗅觉功能;⑤对格氏血厉螨、厩真厉螨、毒厉螨和鼠颚毛厉螨进行涂漆前后的驱避试验,显示当跗感器被涂满封闭,则嗅觉功能消失;④以0.5%结晶紫或龙胆紫液染色的截肢标本,观察了厩真厉螨、毒厉螨、格氏血厉螨、古拉广厉螨及尾足螨股一种螨,足Ⅰ跗节末端凹窝中,至少都存在两类感毛,钝钉型感毛和长而尖的刚毛型感毛;⑤厩真厉螨雌螨和幼螨跗感器的钝钉毛分别为8根和5根,另外各有2根短而尖的毛,分别测定了长度,描述了形态特点;⑥透射电镜观察厩真厉螨、毒厉螨等的跗感器钝钉毛,毛外围有表皮壁,壁上有很多微孔,内有中心腔,腔内有树突。属化感器——嗅觉器;⑦电生理技术研究,当用氨和醋酸的气体刺激厩真厉螨、毒厉螨的离体足Ⅰ时,均产生明显的应激电位差,充分证明足Ⅰ辩节有嗅觉功能。     

Sense organs on palps and fore tarsi of gamasid mites (Parasitiformes, Rhinonyssidae), parasites of the nasal cavity of the Great Tit, the Rock Dove, and the Eurasian Coot

Palpal and tarsal sensilla of mites parasitizing in the nasal cavity of the Great Tit Parus major (Ptilonyssus sairae, Ptilonyssus pari), the Rock Dove Columba livia (Mesonyssus melloi), and the Eurasian Coot Fulica atra (Rallinyssus caudistigmus), were examined under a scanning electron microscope. Differences in the topography of the tarsal organ reflect phylogenetic relations of species and genera, whereas differences in the structure of palpal receptors reflect the ecological peculiarities of parasitism.     

The quill mite <Emphasis Type="Italic">Syringophilopsis fringilla</Emphasis> (Fritsch) (Acari: Trombidiformes: Syringophilidae): the structure of sensory organs providing feeding of the parasite in the feather quill

The structure of the sensory organs situated on palps and chelicerae of the quill mite Syringophilopsis fringilla (Fritsch, 1958) was examined with the use of scanning and transmitting electron microscopy. The tarsal segment of the palps bears 8 sensilla of three types: two contact chemo-mechanoreceptor sensilla, a single chemoreceptor (olfactory) sensillum, and five tactile mechanoreceptor sensilla. All other sensilla situated on basal palpal segments and on cheliceral stylets are represented exclusively by tactile mechanoreceptors. A proprioceptor sensillum was revealed in the movable digit of chelicerae; the modified cilia of dendrites of 5 sensory neurons of this sensillum run inside the inner non-sclerotized core of the stylet and end at different levels in its apical part, attaching to electron-dense rods connected with a sclerotized sheath of the stylet. The authors assume that the proprioceptor sensillum of the stylet detects the strength of the pressure of the stylet of the movable digit on the quill wall during its piercing, and palpal sensilla determine the optimal place for this process.     

Five new species of Rhinonyssidae (Mesostigmata) and one new species of Dermanyssus (Mesostigmata: Dermanyssidae) from birds of Alberta and Manitoba, Canada

Three major lineages of mites are parasitic in the nasal passages of birds, i.e., Rhinonyssidae (Mesostigmata), Ereynetidae (Prostigmata), Cytoditidae, and Turbinoptidae (Astigmata). The most diverse family of avian nasal mites is Rhinonyssidae, which include obligate hematophagous endoparasites of nonratite birds worldwide. Nasal mites have been surveyed extensively in the United States, yet there has never been a Canadian survey. There are only 4 published, and 3 unpublished, rhinonyssid species records from birds in Canada. While surveying the nasal mites associated with birds of Alberta and Manitoba (western Canada), 1 new species of Dermanyssus and 5 new species of Rhinonyssidae were recovered. Herein, I describe and illustrate Dermanyssus diphyes n. sp., Ptilonyssus calvaria n. sp., P. nivalis n. sp., P. pinicola n. sp., P. plesiotypicus n. sp., and Sternostoma setifer n. sp.     

Ultrastructural characterization of antennal sensilla and immunocytochemical localization of a chemosensory protein in Carausius morosus Brünner (Phasmida: Phasmatidae)

The aim of this work was to investigate the olfactory system of the walking stick insect, Carausius morosus. Morphological, ultrastructural and immunocytochemical studies of adult female antennae were conducted by scanning and transmission electron microscopy. Extensive cross-section series were made through the last antennal segment to define the cuticular apparatus, wall pore distribution and the number of innervating receptor neurons of each sensillum type. Single-walled wall pore sensilla occur in three subtypes: (i) with 27 or 28 branched receptor neurons, (ii) with two branched neurons and (iii) with one or two unbranched neurons, respectively. Double-walled wall pore sensilla were found in two subtypes with spoke channels, one with four unbranched neurons, the other with two unbranched neurons. One terminal pore sensillum was found, showing two cavities within the hair and being innervated by six sensory cells. Immunocytochemical experiments were performed to show the localization of a 19 kDa soluble protein found in the chemosensory organs of C. morosus. This protein shows an amino acid sequence homologous to the family of chemosensory proteins (CSP). The polyclonal antibody raised against the purified protein (CSP-cmA) showed, for the first time in CSPs, a strong labeling in olfactory sensilla, specifically in the sensillum lymph surrounding the dendritic branches of SW-WP sensilla and in the uninnervated lumen between the two concentric walls of DW-WP type 1 sensilla.     

The source of chilopod sensory information: External structure and distribution of antennal sensilla in Scutigera coleoptrata (chilopoda,Scutigeromorpha)

The investigation of the antennae of Scutigera coleoptrata (Linnaeus, 1758) by scanning electron microscopy (SEM) revealed the presence of five types of sensilla: sensilla trichodea, beak‐like sensilla, cone‐shaped sensilla brachyconica on the terminal article, sensory cones at the antennal nodes, and the shaft organ. Alongside the presence and absence of antennal sensillar types, three unique characters were found in the Scutigeromorpha: the presence of long antennae with nodes bearing sensory cones, the presence of a bipartite shaft including the shaft organ, and the presence of beak‐like sensilla. Neuroanatomical data showed that the animals' brains are equipped with well‐developed primary olfactory and mechanosensory centers, suggesting that the antennae must be equipped with specialized sensilla to perceive chemosensory and mechanosensory cues. With the evidence provided in this article for the Scutigeromorpha, SEM data are available at last on the antennal sensilla for all five chilopod taxa, allowing a comparative discussion of antennal morphology in Chilopoda. J. Morphol., 2011. © 2011Wiley‐Liss, Inc.     

Fine structure of tarsal sensory organs in the whip spider Admetus pumilio (Amblypygi, Arachnida).

The sensory organs on the tarsi of the antenniform first legs of the whip spider Admetus pumilio C. L. Koch (Amblypygi, Arachnida) were examined with the scanning and transmission electron microscope. At least four different types of hair sensilla were found: (1) thick-walled bristles, which have the characteristics of contact chemoreceptors (several chemoreceptive dendrites in the lumen plus two mechanoreceptors at the base); (2) short club sensilla, innervated by 4-6 neurons which terminate in a pore on the tip; they are possibly humidity receptors; (3) porous sensilla, which are either innervated by 20-25 neurons and have typical pore tubules, or they have 40-45 neurons but no pore tubules; both types are considered to be olfactory; (4) rod sensilla occur in clusters near segmental borders; they are innervated by only one large dendrite which branches inside the lumen. Other tarsal receptors are the claws, which correspond to contact chemoreceptors, and the pit organ which resembles the tarsal organ of spiders. Compared to other arthropod sensilla, the contact chemoreceptors are very similar to those of spiders, while the porous sensilla correspond structurally to olfactory receptors in insects; the club and rod sensilla seem to be typical for amblypygids.     

The main evolutionary trends in sensory organs and questing behavior of Parasitiform ticks and mites

Studies of sensory organs in ticks and mites of the order Parasitiformes by methods of electron microscopy and electrophysiology started in Russia in the middle of the 1970s due to the activity of Prof. Balashov and with his personal participation. A review of the data accumulated since that time allowed tracing the main evolutionary trends in the morphology of the main composite sensory organs (palpal and tarsal organs of mites, Haller’s organ of ticks, and eyes). Close association between the evolution of questing behavior and the evolution of sensory organs is demonstrated.     

贵州东部地区茶园土壤中气和前气门螨种类调查研究（蜱螨亚纲）

报道了贵州东部地区茶园土壤中气门和前气门螨类29种,分属2亚目11科。     

Functional anatomy of sensory structures on the antennae of Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae)

The ultrastructure and distribution of sensilla on the antennae of the cabbage stem flea beetle, Psylliodes chrysocephala, were investigated using scanning and transmission electron microscopy techniques. Eight different sensillar types were distinguished. These were; hair plate sensilla, sensilla chaetica, three types of sensilla trichodea, sensilla basiconica, grooved peg sensilla and styloconic sensilla. The sensilla chaetica are known to be gustatory receptors. Ultrastructure indicates that the hair plate sensilla and sensilla trichodea type one are probably mechanoreceptors, whilst the sensilla styloconica are probably thermo-hygro receptors. These thermo-hygroreceptors are unusual in that they are innervated by two sensory cells (one hygroreceptor and one thermoreceptor) rather than the more usual triad. The remaining four sensillar types all have a porous hair shaft, indicating an olfactory role. One of these (the grooved peg sensillum) may also have a thermoreceptive function. No sexual dimorphism was found in the structure, number or distribution of the antennal sensilla.     

Precibarial and cibarial chemosensilla in the whitefly,Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae)

The internal anatomy of the anterior alimentary canal of the whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) B-biotype, was examined by light, scanning, and transmission electron microscopy to elucidate the location and number of precibarial and cibarial gustatory sensilla. Elucidation of the epipharyngeal organ complex within the precibarium revealed 10 precibarial sensilla located proximal to where the paired maxillary stylets diverge on their retraction. The sensory organ complex within the cibarium consists of 8 sensilla, 6 on the epipharyngeal sclerite with 2 found within the hypopharyngeal sclerite. Fine structure investigation revealed the individual neurons to terminate at sensillar pores, which allow direct contact with passing fluids, thus supporting a chemosensory function. Ultrastructure of the neurons is similar to that of precibarial and cibarial gustatory chemosensilla found in other piercing-sucking insects. Their importance to whitefly feeding is discussed.     

Unusual pheromone receptor neuron responses in heliothine moth antennae derived from inter-species imaginal disc transplantation

Single-cell electrophysiological recordings were obtained from olfactory receptor neurons housed in sensilla trichodea along the adult antennae arising from transplantation of the antennal imaginal discs between larval male Helicoverpa zea and Heliothis virescens. The olfactory receptor neurons from the majority of type C sensilla sampled on transplanted antennae displayed response characteristics consistent with those of the species that donated the antennae. However, some of the sensilla type C sampled in either transplant type contained olfactory receptor neurons that responded in a manner typical of the recipient species or other neurons that have not previously been found in the type C sensilla of either species. The single-cell data help to explain behavioral results showing that some transplant males do fly upwind to both species' pheromone blends, an outcome not expected based on known antennal sensory phenotypes. Our results suggest that host tissue can influence antennal olfactory receptor neuron development, and further that because of a common phylogenetic ancestry the donor tissue has the genetic capability to produce a variety of sensillar and receptor types.     

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.     

Fine structure and distribution of antennal sensilla of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

The fine structure and distribution of various types of antennal sensilla in three nymphal stages and in adults of both solitary-reared (solitary) and crowd-reared (gregarious) phases of the desert locust, Schistocerca gregaria, were investigated by scanning and transmission electron microscopy. Four types of sensilla were identified: sensilla basiconica, s. trichodea, s. coeloconica and s. chaetica. S. basiconica contain up to 50 sensory neurons, each of which displays massive dendritic branching. The sensillar wall is penetrated by a large number of pores. In contrast, s. trichodea contain one to three sensory neurons that branch to give five or six dendrites in the sensillar lumen; the sensillum wall is penetrated by relatively few pores. The s. coeloconica are situated in spherical cuticular pits on the antennal surface. The s. coeloconica are of two types: one type contains one to three sensory neurons with double sensillar walls penetrated by slit-like pores, whereas the second type contains four sensory neurons with non-porous double sensillar walls. The s. chaetica have a flexible socket and a thick non-porous sensillum wall and contain four sensory neurons that send unbranched dendrites to a terminal pore. A fifth sensory neuron of the s. chaetica terminates in a tubular body at the base of the hair. S. basiconica and coeloconica are normally distributed over the entire antennal flagellum, with a concentration in the middle segments; s. trichodea have three areas of concentration on the 5th, 10th and 14th flagellar segments. Sensilla chaetica are most abundant on the terminal segment. Locusts raised in solitary conditions have more olfactory sensilla (s. basiconica and s. coeloconica) than crowd-reared locusts. The difference in sensillar numbers is more evident in adults than in nymphs. These results suggest that differences in the odour-mediated behaviour of nymphs and adults, and between the phases of S. gregaria, may be attributable to differences at the sensory input level.     

Fine structure of tarsal sensilla in the taiga tick Ixodes persulcatus (Ixodinae)

The first tarsal segment of the taiga tick bears 4 general types of sensilla (except for sensilla forming the Haller's sensory organ on the dorsal surface of the tarsus): tactile mechanoreceptor sensilla of 3 types, contact chemo-mechanoreceptor sensilla of 2 types, and double-walled pore sensilla. One of these types, the chemo-mechanoreceptor upper-pore sensilla, was found only in the Ixodinae, and not found in the examined representatives of the Amblyomminae. This type of sensilla was also found in the palpal receptor organ of the ixodid and argasid ticks.     

External morphology and abundance of mouthpart sensilla in Australian Gryllacrididae,Stenopelmatidae, and Tettigoniidae

Sensilla diversity and abundance were extremely high on the apex of the maxillary and labial palpi of two species of Gryllacrididae. The terminal segment of the maxillary palpi of these species had 9 and 15 sensilla types, respectively, and up to 2,834 sensilla. The labial palpi had 7 and 12 types, respectively, and up to 5,195 sensilla. Several types of multiporous smooth and ridged olfactory basiconic sensilla, and coeloconic, coelosphaeric, placoid, and multipapilliform sensilla occurred, as well as many trichoid sensilla and the more typical uniporous basiconic contact receptors. Two species of the closely related Stenopelmatidae were compared to the gryllacridids and found to have similar sensillar diversity and abundance, but three species of the more distantly related Tettigoniidae had only 4 or 5 sensilla types and a total number ranging from 320 to 960 on their maxillary palpi.     

Re-Classification of Drosophila melanogaster Trichoid and Intermediate Sensilla Using Fluorescence-Guided Single Sensillum Recording

Drosophila olfactory receptor neurons are found within specialized sensory hairs on antenna and maxillary palps. The linking of odorant-induced responses to olfactory neuron activities is often accomplished via Single Sensillum Recordings (SSR), in which an electrode inserted into a single sensory hair records the neuronal activities of all the neurons housed in that sensillum. The identification of the recorded sensillum requires matching the neuronal responses with known odor-response profiles. To record from specific sensilla, or to systematically screen all sensillar types, requires repetitive and semi-random SSR experiments. Here, we validate an approach in which the GAL4/UAS binary expression system is used for targeting specific sensilla for recordings. We take advantage of available OrX-Gal4 lines, in combination with recently generated strong membrane targeted GFP reporters, to guide electrophysiological recordings to GFP-labeled sensilla. We validate a full set of reagents that can be used to rapidly screen the odor-response profiles of all basiconic, intermediate, and trichoid sensilla. Fluorescence-guided SSR further revealed that two antennal trichoid sensilla types should be re-classified as intermediate sensilla. This approach provides a simple and practical addition to a proven method for investigating olfactory neurons, and can be extended by the addition of UAS-geneX effectors for gain-of-function or loss-of-function studies.