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Accumulation of DNA sequence data and its use in systematics of the family Argasidae reveals new incongruencies between genera and subgenera, since several groups defined by classical taxonomy appear to be paraphyletic, which is the case of the subgenus Pavlovskyella. In order to identify morphological characters unique to one of the monophyletic groupings within Pavlovskyella and improve its system, we describe all active stages of Ornithodoros (Pavlovskyella) tartakovskyi, a species with an incomplete original description. Larvae, nymphs, males and females from Iran were examined with scanning electron microscopy (SEM). The larva of O. (P.) tartakovskyi lacks dorsal plate, posteromedian seta, postcoxal setae and a spinose area in palpal article I; the dorsal surface has 13 pairs of setae and the hypostome has two short rows of denticles in the apex only. The first nymphal instar (N1) has a micromammillated body with faint dorsal and ventral disks. The second nymphal instar (N2) shows mammillated body with an incipient hood, and dorsal disks outlined as in subsequent instars. Both N1 and N2 have a small patch of glabrous surface in the anterior margin of preanal groove, absent in posterior stages. Third nymphal instar (N3) has a small hood and lack cheeks, which are incipient in the fourth nymphal instar (N4). The four nymphal instars (N1-N4) have blunt hypostomes, striated capitula, non-mammillated legs, and 3 humps on tarsi I. Females and males of O. (P.) tartakovskyi have mammillated bodies, small cheeks not covering the capitulum, the anteromedian disk is placed anteriorly to anterior central disks, and a posterior median file of disks is merged with the median disk. We describe all postembryonic stages of O. (P.) tartakovskyi providing morphological characters that define Pavlovskyella sensu stricto and Theriodoros, a sister subgenus that includes similarly shaped species., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

A trichobothrium is a complex sensory organ, which usually consists of a long, slender mechanoreceptive seta (trich), which is situated in a cuplike depression in the cuticle (bothrium). Nabidae (Hemiptera: Heteroptera: Cimicomorpha), also called damsel bugs, are a relatively small family within which two subfamilies, Nabinae and Prostemmatinae, are distinguished. Trichobothria are present in the number of one to seven pairs located laterally on the scutellum of adult representatives of Prostemmatinae. This feature is commonly used to distinguish this subfamily from Nabinae. Trichobothria are also found on the abdominal tergites of Prostemmatinae nymphs. Similar sensilla have been observed in adult representatives of Nabinae, but their homology has not yet been confirmed. During morphological studies on Nabidae, conducted using scanning electron microscopy, we noticed sensilla resembling trichobothria on the heads of these insects. This discovery prompted us to examine the presence of these structures in damsel bugs more carefully. Imagines of fifteen species of both subfamilies were analysed using a scanning electron microscope. The results present data on the distribution and micromorphology of the trichobothria in damsel bugs. A pair of dorsal and ventral cephalic trichobothria were observed in all of the examined species of subfamily Nabinae. These sensilla were not found on the heads of Prostemmatinae. The results of studies on scutellar trichobothria confirmed the previously known data regarding their occurrence in Prostemmatinae. Moreover, our research showed the presence of these sensory structures in all of the examined Nabinae species: one pair of trichobothria in Arachnocorini, Carthasini, Gorpini and Nabini, and two pairs in Stenonabini. The presence of abdominal trichobothria was shown in Nabini and Stenonabini. In the remaining studied tribes of Nabinae and in the subfamily Prostemmatinae, the presence of structures that could undoubtedly be considered abdominal trichobothria was not found., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To investigate the morphological characteristics of Dermatophagoides farinae at different developmental stages., Methods: The cultured D. farinae was isolated, and the external morphological features of mites at various developmental stages were observed using scanning electron microscopy (SEM), including egg, larva, nymph and adult stages., Results: The D. farinae egg appeared a long oval shape, and the larval mites had three pairs of legs. The nymph had four pairs of legs and underdeveloped genital pores containing genital setae and anal setae, and adult mites appeared long and oval in shape, with decorative patterns on epidermis, and had four pairs of legs. In male adult mites, remarkable thickening of the leg I and thicker and longer leg III than the leg IV were seen, and ventral genital regions were found between the basal segments of legs III and IV; the anus was surrounded by a circular peri-anal ring, with a pair of anal suckers and anal setae within the ring. In the female adult mites, slender legs III and IV with an equal length were seen, and a "λ-shape" genital hole was observed on the ventral surface, with a crescent-like genital plate in the anterior part, and the anus appeared a longitudinal slit., Conclusions: An SEM observation of the external morphology of D. farinae provides understandings of the morphological characteristics of D. farinae , which is of great significance for the classification and identification.

Using serial block-face scanning electron microscopy, we report on the internal 3D structures of the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) at nanometer resolution for the first time. Within the reconstructed organs and tissues, we found many novel and fascinating internal structures in the planthopper such as naturally occurring three four-way rings connecting adjacent spiracles to facilitate efficient gas exchange, and fungal endosymbionts in a single huge insect cell occupying 22% of the abdomen volume to enable the insect to live on plant sap. To understand the muscle and stylet movement during phloem sap-sucking, the cephalic skeleton and muscles were reconstructed in feeding nymphs. The results revealed an unexpected contraction of the protractors of the stylets and suggested a novel feeding model for the phloem sap-sucking., Competing Interests: XW, JG, DL, JH, BM, CZ No competing interests declared, YY Yang Yu is affiliated with Carl Zeiss (Shanghai) Co., Ltd. The author has no financial interests to declare, (© 2021, Wang et al.)

Females, nymphs, and larvae of Ixodes silvanus n. sp. collected from birds and from the vegetation in northwestern Argentina (Yungas Phytogeographic Province) are described herein. The new species belongs to the subgenus Trichotoixodes (Acari: Ixodidae). The female is diagnosed by a combination of the following characters: scutum with setae moderately long and more numerous in central field, fewer and moderately long setae on lateral fields, and inconspicuous setae in anterior field; basis capituli subtriangular dorsally; porose areas large and irregular in shape, lacking distinct margins; auriculae with straight edges diverging posterolaterally and ending with small blunt processes; hypostome narrow and pointed with dental formula 4/4 in the anterior third, then 3/3 and 2/2 near the base; coxae I with two spurs, sub-equal in size, internal slightly slimmer than external. The nymph is diagnosed by notum with numerous and long setae, ventral surface covered by numerous whitish setae, scutum with short scapulae and few and shallow punctations, setae on scutum few, short and irregularly distributed, basis capituli sub-triangular dorsally with posterior margin straight, cornua large and directed postero-laterally, auriculae large and projected laterally, lateral margin of basis capituli above auriculae with a lateral and triangular projection, hypostome pointed with dental formula 3/3 in the anterior third and then 2/2, and coxa I with two short, sub-equal, triangular spurs. The diagnostic characters of the larva are: basis capituli dorsally sub-triangular with lateral angles acute and posterior margin straight, auriculae as large triangular lateral projections, hypostome with apex bluntly pointed and dental formula 3/3 in the anterior third and then 2/2, coxa I with two short, sub-equal, triangular spurs, and pattern of dorsal and ventral body setae. This new species is phylogenetically related to Ixodes brunneus, Ixodes turdus and Ixodes frontalis, and the principal hosts for all its parasitic stages are birds., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Human ectoparasites, including lice, have been recovered from a wide range of archaeological materials. The human head louse, Pediculus humanus capitis, has been identified from mummies and sediments for decades. Louse eggs are the body part most commonly encountered and therefore the most frequently quantified. Typically, several types of microscopy are applied for egg documentation. For studies in which quantification of infestation is a goal, counting is done with the naked eye or with the aid of handheld lenses. For determination and stage classification, stereomicroscopy is commonly used. For more detailed examination of microstructure, light microscopy, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM) can be employed. In most reports, researchers use two or more techniques to accomplish interrelated goals. Automontage microscopy is used to document prehistoric arthropods with good success. Herein, we report the results of a combination of SEM and automontage microscopy to document lice and eggs recovered from South American mummies. This combined approach allows for simultaneous examination of internal and external characteristics. Thirty automontage composite images of 2 adult lice and 16 eggs showed that egg internal morphologies were easily examined showing the within-egg anatomy of emergent nymphs. SEM imaging of 9 lice and 129 eggs was completed. In the case of two adults and several eggs, SEM imaging was accomplish after automontage image capture of the same specimens. This one-to-one image comparison of SEM and automontage shows that transmitted light of automontage reveals egg internal structures and details of the adult lice. SEM allows for high magnification examination of egg, nymph and adult microstructures. We conclude that automontage imaging followed by SEM results in efficient graphic documentation of rare louse specimens., (Copyright © 2020. Published by Elsevier Ltd.)

Ornithodoros cerradoensis n. sp. is described from field-collected and laboratory reared nymphs, males, females, and larvae parasitizing the rodents Cavia aperea and Thrichomys sp. in the Brazilian Savannah. This new species is morphologically and genetically related with the Ornithodoros talaje group and can be separated from other Neotropical species using the following combination of characters: larva with 18 pairs of setae on dorsum (seven anterolateral, four central and seven posterolateral), hypostome with median dentition 2/2; adults provided with large mammillae; dorsal disks surrounded by bulked marginal ridges delimiting barely pebbled areas; three disks in the anterolateral file, and median disk not merging with the posteromedian file. Feeding assays in the laboratory demonstrated that (1) larvae of O. cerradoensis are slow-feeders (∼6 days), (2) first nymphal instar (N1) molts to second instar (N2) without feeding, and (3) N2 and third nymphal instar (N3) engorge rapidly (minutes). With the exception of Ornithodoros hasei nymphs that depict flattened bodies, O. cerradoensis N1, N2, and N3 highly resemble homologous instars of other species in O. talaje sensu lato, therefore are not suitable for morphological comparisons within the group. In addition to morphological signature of larvae and adults that separate this new species; results of cross-mating attempts between O. cerradoensis and Ornithodoros guaporensis a morphologically and phylogenetically closely related species that also parasitizes rodents in the Brazilian Savannah; a Principal Component Analysis using larval characters; and a phylogenetic analysis using mitochondrial markers, support O. cerradoensis as an independent lineage within the Ornithodorinae., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

The horned gall aphid, Schlechtendalia chinensis, inhabits the productive species of Chinese gallnuts, which have economic value. Aphid wax glands are crucial for the survival of the insects, since the secreted waterproofing wax is important to protect the aphids from predators, pathogens and honeydew contamination. In this study, we investigated the structure of wax glands and their role in different aphid stages using light and electron microscopy. Our results show that aphids of all stages except the newly hatched fundatrix possess six parallel dorsal lines and have a total of 56 wax gland plates. Although no wax glands occur on the dorsum of the newly hatched fundatrix (first instar), the glands do appear once a fundatrix enters the second instar. The wax gland plate is composed of 2-22 polygonal depressions, each of which corresponds to a secretory cell covered by cuticle. The wax glands of this aphid belong to the class 1 glands, which are formed by epidermal secretory cells. The structure of the wax glands varies in the different stages and these changes may be adaptive to the changeable microenvironments in which the aphids live., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Kissing bugs (Hemiptera: Reduviidae: Triatominae) are able to bend their rod-like maxillae while searching for blood vessels in the tissue of their vertebrate hosts. Little is known about the working mechanisms of these bending movements and the distal opening of the food channel. We compared the morphological structure of the stylets (mandibles and maxillae) of four triatomine species and analyzed the feeding process of Dipetalogaster maxima (Uhler, 1894). The maxillae of triatomine bugs are interlocked by a tongue-and-groove system, allowing longitudinal sliding. While penetrating the host tissue, the animals perform rapid alternate back and forth movements of the maxillae. The resistance of the surrounding tissue pushes the asymmetric apex of the maxillae away from its straight path, i.e., if one individual maxilla is protracted alone, its tip curves inwards, and the other maxilla follows. Once a blood vessel is tapped, the spine-like tip of the left maxilla splays outwards. Apically, each of the maxillae features an abutment, the left one exhibiting a notch that presumably facilitates splaying. The mechanical interaction of the two maxillary abutments enables the distal opening of the food channel but might also support the movements of the maxillary bundle attributable to different bending moment distributions., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The male accessory glands (MAGs) in insects are pair(s) of internal reproductive organs that produce and secrete the plasma component of seminal fluid. In various insects, MAG size is important for male reproductive success because the fluid provides physiologically active substances and/or nutrients to females to control sperm as well as female reproductive behaviors. Although the MAG epithelial cells in most insect species are standard mononucleate cells, those in some insect taxa are binucleate due to incomplete cytokinesis (e.g., Drosophila [Fallén] [Diptera: Drosophilidae]) or cell fusion (e.g., Cimex [Linnaeus] [Hemiptera: Cimicidae]). In the case of Drosophila, the apicobasal position of the two nuclei relative to the epithelial plane changes from vertical to horizontal after nutrient intake, which allows the volume of the MAG cavity to expand effectively. On the other hand, in the case of Cimex, the positions of the two nuclei do not change apicobasally in response to feeding, but their position relative to the proximodistal axis varies depending on the tubular/spherical organ morphology. Here, we report that the MAG of the benthic water bug Aphelocheirus vittatus (Matsumura) (Hemiptera: Aphelochiridae) shows binucleation in all epithelial cells. Despite the phylogenetically close relationship between Aphelocheirus and Cimex, the MAG cells in Aphelocheirus showed a Drosophila-like apicobasal change in the position of the two nuclei in response to feeding. Furthermore, the cytological processes during binucleation are more similar to those in Drosophila (incomplete cytokinesis) than to those in Cimex (cell fusion). These results indicate that the physiological role and mechanism of binucleation in MAG cells changed during the evolution of Hemiptera., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America.)

Insect cuticular lipids are a complex cocktail of highly diverse cuticular hydrocarbons (CHCs), which form a hydrophobic surface coat to maintain water balance and to prevent desiccation and penetration of exogenous substances. Fatty acid elongases (ELOs) are key enzymes that participate in a common CHC synthesis pathway in insects. However, the importance of ELOs for CHC synthesis and function remains understudied. Using transcriptomic data, we have identified seven ELO genes (LmELO1-7) in the migratory locust Locusta migratoria. We determined their tissue-specific and temporal expression profiles in fifth instar nymphs. As we are interested in cuticle barrier formation, we performed RNA interference against LmELO7, which is mainly expressed in the integument. Suppression of LmELO7 significantly decreased its expression and caused lethality during or shortly after molting. CHC quantification by GC-MS analysis indicated that suppression of LmELO7 resulted in a decrease in total CHC amounts. By consequence, CHC deficiency reduced desiccation resistance and enhanced cuticle permeability in LmELO7-suppressed L. migratoria. Interestingly, LmELO7 expression is induced at low air humidity. Our results indicate that LmELO7 plays a vital role in the production of CHCs and, hence, cuticle permeability. Induction of LmELO7 expression in drought conditions suggests a key role of this gene in regulating desiccation resistance. This work is expected to help developing new strategies for insect pest management based on CHC function., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A new argasid (Argasidae) tick is herein described based on morphology and molecular data obtained from larvae parasitizing Octodon degus and from ticks collected inside burrows in northern Chile. Unfed laboratory-reared larvae were mounted in slides for morphometrical and morphological analyses. Larvae of Ornithodoros octodontus n. sp. share morphological traits with Ornithodoros quilinensis and Ornithodoros xerophylus, two species associated with rodents in the Argentinean Chaco. However, a longer hypostome with two rows of 21 and 22 denticles each one, and conspicuous leaf-shaped anal plates separate O. octodontus. While nymphal stages of O. octodontus lack cheeks and possess a micromammillated dorsal integument, adults have cheeks and exhibit markedly irregular mammillae along their dorsal surface. Phylogenetic analyses of neotropical Argasidae based on mitochondrial 16S rDNA sequences point that O. octodontus forms a monophyletic group with O. xerophylus and an unidentified Ornithodoros sp. from Bolivia, all of them associated with burrow-dweller rodents. Ornithodoros aragaoi and Ornithodoros davisi, two rare species collected once only in the Peruvian Andean Plateau during 1955 are morphologically closely related with adults and nymphs of O. octodontus. Biological observations of O. octodontus revealed autogenic females. For the moment, subgeneric classification of this new species depends on further biological studies. The fauna of ticks occurring in Chile is now represented by 22 species, 11 belonging to the Argasidae family., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

The predatory stink bugs are well known by their behavior, but the knowledge of the immature morphology and their natural history are scarce. Studies on predatory stink bugs are important to better understand their evolution and their use as biological controllers. Here, we describe the morphology of egg and the five nymphal instars of Oplomus catena (Drury, 1782), using optical and scanning electron microscopy. In general, O. catena immatures are very distinctive from other Asopinae species already studied. The egg is black, with short aero-micropylar processes and similar to those described for Stiretrus species. The nymphs can be diagnosed by the abdominal plates very large and bright blue. The color polymorphism of adults is fully illustrated, and four color patterns are proposed. The natural history of the species is described based on field and laboratory observations. The known prey of the species is reviewed and new preys are reported. The morphological and biological traits here described are discussed in order to better understand the biological role of predatory stink bugs.

The genus Belminus Stål, 1859 is distinguished by markedly entomophagous species. This genus is a poorly studied group of the Triatominae (Jeannel, 1919), which includes hematophagous species that are vectors of Trypanosoma cruzi (Chagas, 1909), the etiological agent of Chagas disease. This study reports for the first time the description of the antennal sensilla of Belminus corredori (Galvão & Angulo, 2003), Belminus herreri (Lent & Wygodzinsky, 1979), and Belminus ferroae (Sandoval, Pabón, Jurberg & Galvão, 2007) nymphs and adults throughout scanning electron microscopy and optical microscopy. Nine morphological types of sensilla were identified in the three species, including bristles I and II, trichobothria, tapered hairs, thin-walled trichoid, thick-walled trichoid, basiconic, campaniform, and coeloconica sensilla. The analysis of the most abundant types of sensilla and their distribution in nymphs and adults shows similarities with the antennal phenotypes described in other Triatominae. Quantitative differences showed the important phenotypic plasticity of this morphological trait in the genus and allowed for the separation of the species in both sexes. These differences were associated with sexual dimorphism and wing condition (macropterous and brachypterous). The role of the antennal phenotype in sexual behavior, its usefulness as a taxonomic tool, and its relationship with the dispersal capacity of these species are discussed., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The scale insect, Ericerus pela Chavannes, shows a typical sexual dimorphism. Males and females are different not only in morphology, but also in their ability to secrete wax and ecological adaptability. Here we report the morphological and structural characteristics of wax glands on E. pela females and males. The differences in wax glands and wax secretion between females and males reflect their different needs for living habitats and different ecological strategies. Sciophilous male nymphs are with five types of wax glands, and the wax glands on the dorsum secrete a layer of wax filaments plausibly for protection against direct light irradiation. On the other hand, five types of wax glands were found on the abdomen of females. Heliophilous female nymphs hardly secrete any wax, but the wax glands located along the spiracle on the abdomen may help this insect to breathe. Female adults secrete wax filaments on eggs to protect them from predators and prevent themselves from sticking to each other. In summary, males appear to secreted wax for creating a shaded niche that fits their sciophilous life style, whereas females are likely to adopt an ecological strategy with thickened epidermis for heliophilous acclimatization and overwintering., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

A new species of co-endangered tick, Ixodes heathi n. sp., is described from specimens of the nymph collected on the critically endangered mountain pygmy possum (Burramys parvus Broom) from the alpine region of Victoria, Australia. Its biology is discussed along with strategies for its conservation.

Pharate 1st instar nymphs enclosed in the embryonic cuticle, referred to as pronymphs, were studied in a froghopper Aphrophora pectoralis Mats. (Aphrophoridae) and the leafhoppers Oncopsis flavicollis (L.), Populicerus populi (L.), Alebra wahlbergi (Boh.), Igutettix oculatus (Lindb.), and Scenergates viridis (Vilb.) (Cicadellidae). The species vary in the relative length of the pronymphal antennae and details of sculpturing of the cephalic region. No egg bursting structures were observed, except small denticles on the crown region of S. viridis pronymphs. Rudimentary mandibular and maxillary stylets of a pronymph are external, short, tubular appendages containing tips of the corresponding nymphal stylets, whose more basal parts develop inside of the head. Casting off of the embryonic cuticle results in the nymphal stylets being passively pulled out and assuming a close-set parallel orientation. Once the sheaths of unsclerotized cuticle secreted by the peripodial epithelium and enveloping each developing stylet have been cast off with the exuviae, the bare stylets become squeezed and interlocked into a functional bundle. The roles of the maxillary plates, clypeus, labrum, and labium in the stylet bundle assembly are discussed. The process repeats after each molt., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: To observe the morphological characteristics of live Carpoglyphus lactis at different stages of life cycle and its ultrastructure., Methods: The live C. lactis specimens were isolated from longan pulp, and firstly rinsed with double distilled water under a light microscope to make slide preparation by the conventional manner, and then were made into scanning electron microscope (SEM) specimens. The specimens were observed under SEM for the ultrastructure characteristics at different developmental stages including egg, larva, nymph and adult (male and female) ., Results: The SEM photographs showed that the egg was oval and milky. The larva had three pairs of legs, without genital setae, preanal seta and coxal rod, and there was no trace of genital growth. The nymph had four pairs of legs, genital seta and preanal seta, whereas the genital area was looked still under-developed. The male adult had a conical gnathosoma and a pair of external verticals which were longest setae at the dorsal idiosoma, whereas the other dorsal setae were all short rhabdoid. At the ventral idiosoma, there was an aedoeagus which was like a bent cube, and the top was straight forward. The external sacral setae and post anal were longest setae. The female adult's genital plates were a composite of plastron and cutex inner root, covering the genital tract, and a hole of anus and a pair of anal setae were located at posterior of idiosoma., Conclusions: The morphological characteristics and ultra-structure of C. lactis at different stages of life cycle can be vividly observed under SEM, which provides the morphological bases for further study of the relation between parasitism and disease.

Trombidiform mites are characterized by the presence of several paired glands in the anterior body portion united by a common conducting duct (podocephalic canal). Apart from the acinous (salivary) glands the podocephalic system includes a pair of tubular coxal glands (CGs) responsible for osmoregulation. The aim of the present study was to figure out how functional changes of acinous glands reflect on the corresponding CG. For this purpose, the anatomy and fine structure of the CG were analyzed in two mite species, Bakericheyla chanayi and Ornithocheyletia sp. (Cheyletidae), which have a different composition of their single acinous gland. The results showed that in both species the CG lacks a filtering saccule. It is composed of the proximal and distal tubes and leads into a cuticle-lined excretory duct. Both tubes demonstrate a similar species-specific fine structure. They are characterized by an extensive system of apical membrane invaginations (internal canals) associated with numerous large mitochondria. Local areas of modified internal canals were regularly observed in both species. They contain structures resembling those constituting filtering slit diaphragms of other animals. In O. sp., CG cells in addition demonstrate features characteristic of protein-like secretion. Apparently this correlates with the loss of true salivary glands in this species, as its acinous gland was previously assumed as silk producing. Contrary to this, the CG of B. chanayi shows no kind of granulation, which coincides with the presence of a salivary portion in its complex acinous gland. The microtubule-rich intercalary cells at the base of the excretory duct were associated with special muscles presumably regulating the dilation of the duct lumen. These cells might represent a basic feature common to different types of podocephalic glands., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Stylostomes (feeding tubes) of Hirsutiella zachvatkini (Schluger) (Trombiculidae), feeding on bank voles [Myodes glareolus (Schreber)], and of Trombidium holosericeum (L.) (Trombidiidae), feeding on larvae of Stenodemini sp. (Heteroptera, Miridae), were studied by TEM methods and on semi-thin sections. The stylostome of H. zachvatkini is a homogeneous structure of low electron density and without strict margins. It extends within the concave host epidermis, undergoing hyperplasia and hyperkeratosis. TEM does not reveal any obvious stratification in the stylostome walls. The cheliceral movable digits are moved apart by 5-6 µm and tightly applied/adhered to the stylostome substance. A local area beneath the open end of the stylostome canal is not empty but contains a nearly homogeneous substrate, which can pass into the central stylostome canal. The latter is mostly free of contents. In contrast to H. zachvatkini, larvae of T. holosericeum form a root-like stylostome chaotically branching within the clear space underneath the host cuticle free of tissue elements. Tubules of the distal stylostome branches become progressively thinner and disappear blindly. As in H. zachvatkini, the stylostome walls of T. holosericeum are devoid of stratification but show moderate to high electron density. The cheliceral movable digits are moved apart by the same distance, as in H. zachvatkini, and tightly applied to the stylostome substance. The lumen of the central canal is either electron lucent, in the distal portions, or filled with a fine granular or homogeneous substrate of low electron density in the proximal portions forming a type of ampoule. This study shows that Trombiculidae and Trombidiidae share similar initial stages of stylostome formation but the resultant stylostome of each family is distinctly different.

The climbing abilities of two bed bug species, Cimex lectularius L. and Cimex hemipterus (F.), were determined by evaluating their escape rates from smooth surface pitfall traps using four commercial bed bug monitors (Verifi Bed Bug Detector, ClimbUp Insect Interceptor, BlackOut Bed Bug Detector, and SenSci Volcano Bed Bug Detector). All detectors were used in the absence of lures or attractants. Unlike C. lectularius, adult C. hemipterus were able to escape from all traps. On the other hand, no or a low number nymphs of both species escaped, depending on the evaluated traps. Examination of the vertical friction force of adults of both species revealed a higher vertical friction force in C. hemipterus than in C. lectularius. Scanning electron microscope micrograph observation on the tibial pad of adult bed bugs of C. hemipterus showed the presence of a greater number of tenent hairs on the tibial pad than on that of adult C. lectularius. No tibial pad was found on the fourth and fifth instars of both species. Near the base of the hollow tenent hairs is a glandular epithelium that is better developed in adult C. hemipterus than in adult C. lectularius. This study highlights significant morphological differences between C. lectularius and C. hemipterus, which may have implications in the monitoring and management of bed bug infestations., (© The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Sogatella furcifera Horváth (Hemiptera: Delphacidae), is a major migratory pest of rice crops in Asia. The ultrastructure of the flight muscle directly affects the flight ability of insects. The ultrastructure of the flight muscle of some insects can be affected by insecticides. However, the ultrastructure of the flight muscle of S. furcifera and the effect of insecticides on the flight muscle of S. furcifera are not well understood. The present study was conducted to determine the effect of the insecticide dinotefuran on the ultrastructure of the flight muscle of S. furcifera females. In this study, the cross-sectional area and the diameter of the myofibril cross-sections of dinotefuran-treated S. furcifera females increased with the number of days after emergence (DAE), and they were higher than in untreated females. The sarcomere length of myofibrils increased with the number of DAE, and it differed from that of the untreated females. On the first day after emergence, the higher the concentration of dinotefuran, the smaller was the extent of decrease. On the third day after emergence, the higher the concentration of dinotefuran, the larger was the extent of enhancement. For the percentage of mitochondria, those of LC10 and LC20 dinotefuran-treated S. furcifera females increased with the number of DAE and were higher than in untreated females. LC10 dinotefuran-treated S. furcifera females exhibited the largest increase. Thus, our results suggest that the flight ability of S. furcifera increased with time. Some concentrations of dinotefuran can enhance the flight capacity of S. furcifera., (© The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The antennae of Insecta consist of two basal segments and the distal annulated flagellum lacking intrinsic muscles. Non-muscular joints are important to preserve the flexibility and structure of the long heteropteran antennae which bear an intersegmental nodule on each non-muscular joint. Little is known about their properties or function. Here we characterize the structure and postembryonic development of the non-muscular joints of Rhodnius prolixus antennae. Using Scanning Electron Microscopy, we tracked the changes in shape and size of both intersegmental nodules during the course of the hemimetabolous insect life cycle. Using Atomic Force Microscopy, we established a qualitative correlation between the topography of the surface and the rigidity of the joint between pedicel and flagellum. Our results confirmed the presence of two sub-articulations on each non-muscular joint. Also, the two intersegmental nodules have different origins: the one between the two flagellar segments (intraflagelloid) is a sclerite already present from the early nymph, while the nodule between pedicel and flagellum (prebasiflagellite) originates by gradual separation of the proximal end of the basiflagellum during postembryonic development. Various changes occur in the non-muscular joints and segments of the antenna during the life cycle of R. prolixus., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The stick insect Peruphasma schultei stands out from other insects by its deep matt black cuticle. We tested whether the appearance of P. schultei is due to microstructures of the cuticle, a phenomenon that has recently been described for the velvet black scales of the Gaboon viper. The shiny black stick insect Anisomorpha paromalus served as a control. We found that the P. schultei cuticle is characterised by two different types of microstructures, tall elevations with a maximum size of 18 μm and small structures with a height of 4 μm. Other than in the snake, P. schultei microstructures do not bear nanostructures. The microstructures scatter light independently of the viewing angle. This causes the matt appearance of the cuticle, whereas pigments are responsible for the black colouration, resulting in a maximum reflectance of 2.8% percent. The microstructures also cause the hydrophobic properties of the cuticle with contact angles near 130°. Resin replicas and bleaching of the cuticle strongly support these results. Moreover, the matt black cuticle has a higher heat absorption compared to the control. We discuss the selective benefit of the matt black appearance of P. schultei in the context of behaviour, ecology and phylogeny., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Development of the mouthparts in the cicada Meimuna mongolica (Distant) is investigated here for the first time using scanning electron microscopy in order to document changes occurring in different nymphal instars and from nymph to adult, during which a shift from subterranean root-feeding to feeding on aboveground parts of the host plant occurs. The structure and component of mouthparts is similar to those found in other hemipteran insects. Fourteen types of sensilla and five types of cuticular processes were found on the mouthparts of nymphs and adults. Significant general transformations during development include changes in: (a) the size and shape of the labrum from square to long and shovel-shaped; (b) increases in type and quantity of sensilla with the stage of development; (c) the ridges at the tips of the mandiblar stylets become more prominent in later stages of nymphal development, while odontoid protrusions more prominent in the female than in the male of the adult; and (d) the cross section of the stylets is subcircular in nymphal stages but oblong elliptical in the adult. The implications of these mouthpart transformations on the feeding ability of nymphs and adults and their possible relationship to the feeding niche are discussed.

Amblyomma integrum Karsch, 1879 (Acari: Ixodidae) is one of four Amblyomma Koch, 1844 species with eyes found in southern India and Sri Lanka. The immature stages of this species were poorly described. Therefore, accurate identification is difficult. Here we re-describe the male, female, nymph and larva of A. integrum and illustrate all the stages in greater detail for the first time. A set of diagnostic morphological characters is defined to distinguish this species from other sympatric species of eyed Amblyomma in any parasitic stage of development. Adults of A. integrum parasitize mostly various larger mammals whereas nymphs and larvae use mostly larger and medium mammals. Amblyomma integrum is recorded from India (Andhra Pradesh, Goa, Karnataka, Orissa and Tamil Nadu States) and throughout Sri Lanka., (© 2016 The Royal Entomological Society.)

Peloridiidae are a family of small hemipterans who live and feed on bryophytes of temperate forests in some regions of the Southern Hemisphere. They are often submerged in water and would require adaptations for respiration to tolerate periods of inundation. Here we report water-repelling cuticular structures on the tergites of thorax and abdomen and on the ventral surface of tegmina in Peloridiidae. Our observations show that these body parts can hold an air bubble or layer which is in contact with spiracles. Thus, the described structures comply with the definition of a structural plastron. The micromorphology of these structures was studied with a SEM on adults and nymphs of several species and their hydrophobicity was tested in two species with a contact angle goniometer. Possible implications for the standard plastron definition are discussed, as well as its significance for systematics, origin and biogeography of the group., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Larvae, nymphs and adults of the cave dwelling tick Ornithodoros dyeri, collected in 3 Mexican states, were studied using morphological and molecular methods. The adults and nymphs were characterized by an elongated body in proportion to the width and a dorsum bounded by two contiguous ridges and one third ridge (inner) that was incomplete on each side. The larvae of this species have 14 pairs of dorsal setae, a venter body with nine pairs of setae plus a posteromedian; a moderately large, dorsal plate and piriform, a hypostome arising from a relatively short, subtriangular median extension of the basis capituli, and a capsule of Halleŕs organ with reticulations. Based on a maximum likelihood analysis of the sequences of a fragment of approximately 414bp of the mitochondrial 16S rRNA gene, we showed that O. dyeri represents an independent lineage within neotropical species of the Argasidae. The bat species Mimon cozumelae and Peropteryx macrotis represents a new host record for this argasid., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The development and organization of the ovaries of ten species from four Psylloidea families (Psyllidae, Triozidae, Aphalaridae and Liviidae) have been investigated. The ovaries of the last larval stage (i.e. fifth instar) of all examined species are filled with numerous clusters of cystocytes which undergo synchronous incomplete mitotic division. Cystocytes of the given cluster are arranged into a rosette with polyfusome in the centre. These clusters are associated with single somatic cells. At the end of the fifth instar, the clusters begin to separate from each other, forming spherical ovarioles which are surrounded by a single layer of somatic cells. In the ovarioles of very young females all cystocytes enter the prophase of meiosis and differentiate shortly thereafter into oocytes and trophocytes (nurse cells). Meanwhile, somatic cells differentiate into cells of the inner epithelial sheath surrounding the trophocytes and into the prefollicular cells that encompass the oocytes. During this final differentiation, the trophocytes lose their cell membranes and become syncytial. Oocytes remain cellular and most of them (termed arrested oocytes) do not grow. In the ovarioles of older females, one oocyte encompassed by its follicle cells starts growing, still connected to the syncytial tropharium by a nutritive cord. After the short phase of previtellogenesis alone, the oocyte enters its vitellogenic the growth phase in the vitellarium. At that time, the second oocyte may enter the vitellarium and start its previtellogenic growth. In the light of the obtained results, the phylogeny of psyllids, as well as phylogenetic relationships between taxa of Hemiptera: Sternorrhyncha are discussed., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

We detail gross and histopathological changes associated with infection by the eggs, larvae, and cuticular remnants of Unionicola sp. in the mantle, gill, and visceral mass of 25 Alabama creekmussels, Strophitus connasaugaensis, collected during May 2010 through July 2012 from 2 Alabama streams. A multitude (estimated mean intensity >100) of mite eggs and larvae typically infected mantle, gill, and visceral mass integument. Pathology associated with eggs (prevalence = 0.57) and larvae (prevalence = 0.39) typically consisted of localized distension of the infection site; a host response to these infections was indeterminate. However, larval mites embedded in suprabranchial connective tissues were typically encapsulated (prevalence = 0.89). Mite remnants (prevalence = 0.5) occurred in mantle, gill, visceral mass integument, foot, heart, pericardial gland, intestinal lamina propria, and were typically encapsulated. We speculate that S. connasaugaensis clears some infections but is recolonized by autoinfection or horizontal dispersal of mites in the stream. Noteworthy is that high-intensity infections seemingly do not markedly impact the histological picture of mussel tissues, indicating that mites are relatively benign symbionts that are of little concern to mussels under normal environmental conditions.

The larva of the dragonfly Onychogomphus forcipatus (Anisoptera, Gomphidae) has a burrowing lifestyle and antennae composed of four short and broad segments (scape, pedicel and a two-segmented flagellum). The present ultrastructural investigation revealed that different sensilla and one gland are located on the antenna. There is a great diversity of mechanoreceptors of different kinds. In particular club-shaped sensilla, sensilla chaetica, and tree-like sensilla show the typical structure of bristles, the most common type of mechanoreceptors, usually responding to direct touch, while numerous long thin thorny trichoid sensilla show a morphology recalling the structure of filiform hair mechanoreceptors. The latter ones are presumably important in larval Odonata for current detection and rheotactic orientation, especially in a burrowing species. On the smooth apical cuticle of the second flagellar segment, three structures are visible: (1) a small ellipsoidal pit hosting a convoluted peg, the morphology of which resembles that of a typical chemoreceptor (even if pores are lacking), (2) a couple of small pits (not investigated under TEM), and (3) one wide depression with spherical structures, the internal morphology of which lets us assume that it is a gland with unknown function. This is the first report of an antennal gland in palaeopteran insects., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Low temperature scanning electron microscopy (LT-SEM) has revealed anatomical details suggesting that Osperalycus and Gordialycus (Acariformes: Nematalycidae) have an unusual feeding apparatus that is hypothesized to be specialized for feeding on the fluid contents of small microorganisms (diameter<5 μm). Both mite genera have a feeding strategy that appears to involve picking up small microorganisms and placing them onto the subcapitulum for puncturing. However, they have slightly different variants of the same basic rupturing mechanism. Whereas Gordialycus has evolved expansive and convergent rutella to hold the microorganisms in place while pushing chelicerae into them, Osperalycus has evolved a pouch into which a microorganism is inserted. The rutella reinforce this pouch while the chelicerae break up the microorganism. Both types of mouthpart apparatus seem to be adapted to minimize waste, an appropriate specialization given the organically impoverished habitats in which these mites live., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Insect nephrocytes are cells bathed in hemolymph and considered to have an excretory function. These cells have ambiguous nomenclature and are understudied in termites. This study is the first report on the occurrence, morphology and function of nephrocytes in different termite castes. Cytological characteristics in specific developmental stages and castes enable physiological functions to be inferred. Perforate diaphragms indicate a role in filtration, while the extensive peripheral invaginations of the cell membrane suggest active endocytosis. A sequence of morphologies in putative digestive vacuoles infers a lysosomal system and the occurrence of phosphatases suggests a function involving detoxification of substances sequestered from hemolymph. Pericardical nephrocytes took up the dye trypan blue injected in live termites, suggesting their activity connected to the filtration of the hemolymph. Additionally, histochemical tests showed the existence of stored proteins in their cytoplasm. These cells present a well-developed Golgi apparatus and abundant rough endoplasmic reticulum, consistent with protein synthesis. This study highlights the importance of nephrocytes in Isoptera and opens perspectives for further research of these cells., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A specific type of maternal care occurs in several groups of Arachnida: mothers carry their offspring on their back (pulli-carrying behaviour). In scorpions, whip scorpions and whip spiders it is the prenymphal stage that settles on the mother. The prenymph is not yet fully developed for a free life and very limited in its mobility, but its feet are equipped with special adhesive organs (arolia) that become lost at the nymphal stage. Here we study the morphology, ultrastructure and mechanical function of the arolia. In scorpions (Scorpiones) the contact area between arolia and substrate and thus adhesion of the pad is controlled by the antagonistic work of hydrostatic pressure and muscular retraction. Arolia of whip scorpions (Thelyphonida) do not require muscular action for strong attachment. Arrays of long, branching fibres in the mesocuticle lead to high compliancy of the pad. In whip spiders (Amblypygi) the prenymphal pretarsus is already equipped with sclerites and claws. Its arolium is retained in nymphs and adults in some taxa, but acquires a more complex structure. These results contribute to our knowledge on the postembryonic development of arachnids and to the understanding of attachment pad evolution among arthropods. Some of the described developmental, structural, and mechanical phenomena are not known from other animals and might be of potential interest for further biomimetic developments., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Insects have developed different structures to adhere to surfaces. Most common are smooth and hairy attachment pads, while nubby pads have also been described for representatives of Mantophasmatodea, Phasmida and Plecoptera. Here we report on the unusual combination of nubby and smooth tarsal attachment structures in the !nara cricket Acanthoproctus diadematus. Their three proximal tarsal pads (euplantulae) have a nubby surface, whereas the most distal euplantula is rather smooth with a hexagonal ground pattern resembling that described for the great green bush-cricket Tettigonia viridissima. This is, to our knowledge, the first report on nubby euplantulae in Orthoptera and the co-occurrence of nubby and smooth euplantulae on a single tarsus in a polyneopteran species. When adhering upside down to a horizontal glass plate, A. diadematus attaches its nubby euplantulae less often, compared to situations in which the animal is hanging upright or head down on a vertical plate. We discuss possible reasons for this kind of clinging behaviour, such as morphological constrains, the different role of normal and shear forces in attachment enhancement of the nubby and smooth pads, ease of the detachment process, and adaptations to walking on cylindrical substrates.

A microtubule organizing centre (MTOC) has been described in the spermatid of the hemipteran Matsucoccus feytaudi (Coccoidea). This structure, revealed as a fluorescent ring by treatment with γ-tubulin antibody, gives rise to a bundle of microtubules which surrounds the elongated cylindrical nucleus. This microtubule bundle has been considered an atypical sperm flagellum provided with sperm motility. A comparison of the M. feytaudi MTOC with the material associated with the centriole of Drosophila melanogaster spermatids confirms the great similarity between the two structures, both involved in the nucleation of microtubules. Like the D. melanogaster material associated with the centriole, the M. feytaudi MTOC is a transient structure which disappears or degenerates at the end of spermiogenesis and is no longer visible in the mature sperm., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of 'naturally waxed' and 'dewaxed' nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed.

The histopathological changes of the second instar nymph of the mealybug Phenacoccus fraxinus infected with Lecanicillium lecanii strain 3.4505 were investigated using light, scanning and transmission electron microscopy. The results demonstrated that L. lecanii 3.4505 could infect P. fraxinus in a short period. At 24 h post-inoculation, the conidia of L. lecanii 3.4505 adhered to the indented gloves or intersegmental folds of the insect body surface. Subsequently, the germinated conidia produced germ-tubes, appressoria and extended hyphae, which tightly adhered to the cuticle. Penetration of cuticle could be achieved either by peg form appressoria or directly by hyphae. Also, the conidia and hyphae could secrete massive mucilages causing visible damage to the host cuticle. After 48 h, the body wall, tissues and organs, including cuticle, trachea, fat body, muscle, Malpighian tubules and nerve ganglion, were destroyed by ramification of hyphae as a result of infection. The endoplasmic reticulum hypertrophied and formed obvious fingerprint agglomerates, and the mitochondria swelled and deformed in the haemocytes. Finally, the mycelium fully occupied the entire haemocoel. The entire bodies were wrapped in a white mycelium, with the mycelium extending radically outward.

Whiteflies have distinct nymphal stages: their first stage is mobile, whereas the later immature stages are sessile. The developmental and structural changes of antennae and antennal sensilla in whiteflies during these stages have rarely been investigated. This paper describes the morphology of antennae and antennal sensilla in four nymphal stages of Aleurodicus dispersus based on scanning electron microscopy. There were significant differences found in shape and length of the antennae, and differences in type, number, morphological structure and distributional pattern of antennal sensilla in the four nymphal stages of A. dispersus. We found two types of sensilla on the antennae of first-instar nymph, three types on the third-instar nymphal antennae, four types on the second-instar and seven types on the fourth-instar nymphal antennae. Sensilla trichoidea (ST) and elevated sensilla placodea were found on the antennae of each nymphal stage, sensilla chaetica only occurred on the antennae of fourth-instar nymph. Sensilla furcatea occurred on the antennae of second- and third-instar nymphs, and sensilla basiconica were found on the antennae of second- and fourth-instar nymphs. In addition, there were sensilla campaniform and sensilla coeloconica found only on the antennae of fourth-instar nymph, whereas the ST of fourth-instar nymphs included sensilla trichoidea 1 and sensilla trichoidea 2. The possible functions of antennal sensilla are discussed. Our results contribute to a better understanding of the development of the olfactory system of whitefly nymphal stages, and provide a basis for further exploration of chemical communication mechanisms between whiteflies and host plants.

Matsucoccus matsumurae (Kuwana) (Hemiptera: Coccoidea: Matsucoccidae) is an invasive alien species and a destructive pest of two native Chinese pines, Pinus tabulaeformis Carr. and P. massoniana Lamb., throughout the eastern regions of China. The pathogenicity of three entomopathogenic fungi, Lecanicillium lecanii strain V3.4504 and V3.4505, Fusarium incarnatum-equiseti strain HEB01 and Lecanicillium fungicola strain HEB02, against M. matsumurae was tested in four instars, to evaluate their potential as a biological control agent. The results showed that the four strains caused disease and death of the scale insect, among which the L. lecanii strains V3.4504 and V3.4505 displayed stronger virulence than the F. incarnatum-equiseti strains HEB01 and L. fungicola strain HEB02 to M. matsumurae in the 2nd-instar nymphs and the adult females. Furthermore, L. lecanii V3.4505 was most virulent to M. matsumurae. The adult females and the male 3rd-instar nymphs of M. matsumurae were susceptible to L. lecanii V3.4505; the adult females were more susceptible at LT50 = 1.96 than the 3rd-instar nymphs at LT50 = 5.67. The body surface structure, cuticle thickness and wax secretions of M. matsumurae impacted the fungal infection. L. lecanii is a promising biocontrol agent, and newly emerged male 3rd-instar nymphs and adult females are a crucial period of the insect's life cycle for M. matsumurae biocontrol.

The development of male and female gonads in arrhenotokous and thelytokous species of Histiostoma was studied using transmission electron microscopy (TEM). All instars were examined: larvae, protonymphs, facultative heteromorphic deutonymphs (=hypopi), tritonymphs, and adults. In testis primordium, spermatogonia surrounding a testicular central cell (TCC) with a gradually enlarging, branched nucleus are present already at the larval stage. Spermatogonia and the TCC are connected via narrow, tubular intercellular bridges revealing that the TCC is a germline cell. Spermatocytes appear at the protonymphal stage. At the heteromorphic deutonymph stage, the testis primordium is similar to that of the protonymph, but in the tritonymph it is much larger and composed as in the adult: spermatids as well as sperm cells are present. The latter are congregated ventrally in the testis at the entrance of the deferent duct. In the larval ovary, an eccentrically located ovarian nutritive cell (ONC) is surrounded by oogonia which are connected with the ONC via tubular intercellular bridges. In later stages, the ovary grows and oocytes appear in the protonymph. Meiotic synaptonemal complexes in oocytes occur from the tritonymph stage. At about the time of the final molting, tubular intercellular bridges transform into peculiar diaphragm-crossed bridges known only in Histiostoma mites. In the adult female, growing oocytes at the end of previtellogenesis lose intercellular bridges and move ventro-laterally to the ovarian periphery towards the oviduct entrance. Vitellogenesis occurs in oviducts. Germinal cells in both the testis and ovary are embedded in a few somatic stroma cells which may be well discernible already in the larval ovary; in the testis, somatic stroma cells are evident not earlier than the end of the tritonymphal stage. The ovary has a thin wall of flat somatic cells, whereas the testis is covered by a basal lamina only. The obtained results suggest that gonads in Histiostoma and other Astigmata originate from two primordial cells only., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

In apoikogenic scorpions, growing oocytes protrude from the gonad (ovariuterus) and develop in follicles exposed to the mesosomal (i.e. hemocoelic) cavity. During subsequent stages of oogenesis (previtellogenesis and vitellogenesis), the follicles are connected to the gonad surface by prominent somatic stalks. The aim of our study was to analyze the origin, structure and functioning of somatic cells accompanying protruding oocytes. We show that these cells differentiate into two morphologically distinct subpopulations: the follicular cells and stalk cells. The follicular cells gather on the hemocoelic (i.e. facing the hemocoel) surface of the oocyte, where they constitute a cuboidal epithelium. The arrangement of the follicular cells on the oocyte surface is not uniform; moreover, the actin cytoskeleton of these cells undergoes significant modifications during oocyte growth. During initial stages of the stalk formation the stalk cells elongate and form F-actin rich cytoplasmic processes by which the stalk cells are tightly connected to each other. Additionally, the stalk cells develop microvilli directed towards the growing oocyte. Our findings indicate that the follicular cells covering hemocoelic surfaces of the oocyte and the stalk cells represent two distinct subpopulations of epithelial cells, which differ in morphology, behavior and function., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Haemaphysalis qinghaiensis Teng (Acta Zootaxon Sin 5:144-149, 1980) is an endemic species in China. This tick species was first described based on engorged or semi-engorged specimens, and the drawings and description in words of morphological characteristics were poor. Therefore, the present study aims to redescribe morphological characteristics of all active stages of this tick species in detail by scanning electron microscopy. Additionally, a comparison between H. qinghaiensis and other sympatric Haemaphysalis species was also analyzed. Males of H. qinghaiensis can be distinguished from sympatric Haemaphysalis species by the following characters: palpi less salient laterally and curved in contour; ventrointernal setae of palpal segment II thin, number <7; the tips of palpal segment III not so strongly recurved inward to become "pincerlike" and lacking dorsal spur; dental formula 5/5; lateral grooves enclose first festoon; coxa IV with a short, broadly triangular spur; tarsi somewhat humped; and spiracular plates long comma-shaped. Females of H. qinghaiensis can be distinguished by palpi less salient laterally and curved in contour; ventrointernal setae of palpal segment II thin, number <7; segment III of palpi lacking dorsal spur; dental formula 4/4; scutum subcircula; and tarsi somewhat humped. Nymphs of H. qinghaiensis can be distinguished from those of other species by palpi less salient laterally and curved in contour; dental formula 2/2; basis capituli rectangular, with distinct dorsal cornua, without ventral cornua; and spiracular plates with short and narrow dorsal prolongation. Larvae of H. qinghaiensis can be distinguished by palpi less salient laterally and curved in contour; basis capituli rectangular, without distinct cornua.

The Heteroptera show a diversity of glands associated with the epidermis. They have multiple roles including the production of noxious scents. Here, we examine the cellular arrangement and cytoskeletal components of the scent glands of pentatomoid Heteroptera in three families, Pentatomidae (stink bugs), Tessaratomidae, and Scutelleridae (shield-backed bugs or jewel bugs). The glands are; (1) the dorsal abdominal glands, (2) the tubular glands of the composite metathoracic gland, and (3) the accessory gland component of the composite metathoracic gland. The dorsal abdominal glands are at their largest in nymphs and decrease in size in adults. The metathoracic gland is an adult-specific gland unit with a reservoir and multiple types of gland cells. The accessory gland is composed of many unicellular glands concentrated in a sinuous line across the reservoir wall. The lateral tubular gland is composed of two-cell units. The dorsal abdominal glands of nymphs are composed of three-cell units with a prominent cuticular component derived from the saccule cell sitting between the duct and receiving canal. The cuticular components that channel secretion from the microvilli of the secretory cell to the exterior differ in the three gland types. The significance of the numbers of cells comprising gland units is related to the role of cells in regenerating the cuticular components of the glands at moulting in nymphs., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Rhipicephalus sanguineus is a species of tick which is widely distributed in America, Africa and Australia and is probably the most prevalent among all the other ixodid tick species. The present study demonstrated the effects of the arthropod growth regulator fluazuron (Acatak(®)), in the formation of the integument and the digestive processes of R. sanguineus nymphs fed on rabbits treated with different doses of this chemical acaricide. For this, three different doses of fluazuron (20mg/kg, 40mg/kg and 80mg/kg) were applied "pour on" to the hosts divided into three different treated-groups (II, III, IV) of three animals each. A fourth group (I) of rabbits (n=3) was given distilled water as control. On the first day after treatment (24h), the hosts were artificially infested with R. sanguineus nymphs. After full engorgement (7 days), the nymphs were removed and placed on labeled Petri dishes and kept in BOD incubator for 7 days. The engorged nymphs were then taken to ultra-structural analysis. Results revealed the following main ultra-structural changes in the nymphs integument and midgut of the different treated groups (II, III, IV): cuticle disorganization and the absence of subdivisions, damages in the integument epithelial cells, size of digestive cells, amount of endosomes, autophagic and digestive vacuoles, accumulated digestive residues, lipid droplets and organelles found in the digestive cells' cytoplasm, as well as the presence of microvilli in their plasma membranes. It is concluded that fluazuron may act on the integument and midgut cells of R. sanguineus engorged nymphs by impairing the synthesis of the new cuticle and the digestive processes (absorption of the blood ingested from the host, digestion - hemolysis, formation of digestive residues and release of nutrients to be converted into lipid, as well as for the synthesis of structural protein), which interfere in the development of nymphs, being able to prevent the emergence of adults after periodical ecdysis. These data indicate the possibility to use this arthropod growth regulator (AGR) in the control of R. sanguineus, at least in the nymphal stage of its biological cycle., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this paper, the wax secretions and wax glands of Matsucoccus matsumurae (Kuwana) at different instars were investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. The first and second instar nymphs were found to secrete wax filaments via the wax glands located in the atrium of the abdominal spiracles, which have a center open and a series of outer ring pores. The wax gland of the abdominal spiracle possesses a large central wax reservoir and several wax-secreting cells. Third-instar male nymphs secreted long and translucent wax filaments from monolocular, biolocular, trilocular and quadrilocular pores to form twine into cocoons. The adult male secreted long and straight wax filaments in bundles from a group of 18-19 wax-secreting tubular ducts on the abdominal segment VII. Each tube duct contained five or six wax pores. The adult female has dorsal cicatrices distributed in rows, many biolocular tubular ducts and multilocular disc pores with 8-12 loculi secreting wax filaments that form the egg sac, and a rare type wax pores with 10 loculi secreting 10 straight, hollow wax filaments. The ultrastructure and cytological characteristics of the wax glands include wax-secreting cells with a large nucleus, multiple mitochondria and several rough endoplasmic reticulum. The functions of the wax glands and wax secretions are discussed., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The five instars of Tingis (Tingis) americana Drake are described and illustrated, with emphasis on the ontogenetic changes of integumentary structures. The study was performed using scanning electron microscopy.

Lyme disease, due to infection with the Ixodes-tick transmitted spirochete Borrelia burgdorferi, is the most common tick-transmitted disease in the northern hemisphere. Our understanding of the tick-pathogen-vertebrate host interactions that sustain an enzootic cycle for B. burgdorferi is incomplete. In this article, we describe a method for imaging the feeding of Ixodes scapularis nymphs in real-time using two-photon intravital microscopy and show how this technology can be applied to view the response of Lyme borrelia in the skin of an infected host to tick feeding.

The genus Paracholula Harrington has been represented by two species, P. picta (Fab) and P. thoracica (Distant), both recorded from Mexico. Individuals of one population from Guerrero were studied and compared with individuals of both species from different collections, including the types. Using scanning electron micrographs of different structures, and observation of the male genitalia of some individuals, together with a close examination of all the individuals from the population from Guerrero, we discovered, that there is great variation in all the structures and that some characters that were used to separate the two species are present within the population from Guerrero. Therefore we synonymize both species, stating that the valid name for this species is Paracholula picta (Fab). Descriptions and illustrations of all the immature stages from the Guerrero population are included. Notes about host plants, biology and distributional records are also included.

The present study evaluated the efficacy of fluazuron (active ingredient of the acaricide Acatak®) and its effects on Rhipicephalus sanguineus nymphs fed on rabbits exposed to different doses of this insect growth regulator. Three different doses of fluazuron (20 mg/kg, 40 mg/kg, and 80 mg/kg) were applied on the back of hosts (via "pour on"), while distilled water was applied to the Control group. On the first day of treatment with fluazuron (24 h), hosts were artificially infested with R. sanguineus nymphs. Once fully engorged, nymphs were removed and placed in identified Petri dishes in Biochemical Oxygen Demand (BOD) incubator for 7 days. After this period, engorged nymphs were processed for ultramorphological analysis. The results revealed alterations in the ultramorphology of many chitinous structures (smaller hypostome and chelicerae, less sclerotized scutum, fewer sensilla, fewer pores, absence of grooves, marginal and cervical strips and festoons in the body, even the anal plaque was damaged) that play essential roles for the survivor of ticks and that can compromise the total or partial development of nymphs and emergence of adults after periodic molting. Our findings confirm the efficacy of fluazuron, a more specific and less aggressive chemical to the environment and human health, and that does not induce resistance, in nymphs of the tick R. sanguineus in artificially infested rabbits treated with this arthropod growth regulator (AGR), indicating that it could be used in the control of this stage of the biological cycle of the tick R. sanguineus., (Copyright © 2013 Wiley Periodicals, Inc.)