Acoustic Component and Social Context of the Wing Display of the Walnut Fly Rhagoletis juglandis

Courtship signaling via wing vibration, accompanied by sound production, has been reported in several species of tephritids. In this large family of flies, sound communication as well as complex courtship displays appears to be restricted to species with lekking mating systems (i.e., Mediterranean fruit fly, Anastrepha and Dacus species). In contrast, in tephritid species with resource-defense mating systems, such as species in the genus Rhagoletis, little or no courtship behavior, acoustical or otherwise, has been described. Wing displays in Rhagoletis species have been considered to play a visual role. This study describes a distinctive wing display performed by males of the walnut fly, Rhagoletis juglandis. Laboratory experiments and field observations demonstrate that the male wing display plays a role in courtship. We used sound and vibration detectors to record the signals produced by this wing display. Using a combination of techniques, we were able to record both the very low-frequency vibration and its accompanying airborne infrasound (12–22 Hz) produced by the males.     

Microbial Population Analysis of the Salivary Glands of Ticks; A Possible Strategy for the Surveillance of Bacterial Pathogens

Ticks are one of the most important blood-sucking vectors for infectious microorganisms in humans and animals. When feeding they inject saliva, containing microbes, into the host to facilitate the uptake of blood. An understanding of the microbial populations within their salivary glands would provide a valuable insight when evaluating the vectorial capacity of ticks. Three tick species (Ixodes ovatus, I. persulcatus and Haemaphysalis flava) were collected in Shizuoka Prefecture of Japan between 2008 and 2011. Each tick was dissected and the salivary glands removed. Bacterial communities in each salivary gland were characterized by 16S amplicon pyrosequencing using a 454 GS-Junior Next Generation Sequencer. The Ribosomal Database Project (RDP) Classifier was used to classify sequence reads at the genus level. The composition of the microbial populations of each tick species were assessed by principal component analysis (PCA) using the Metagenomics RAST (MG-RAST) metagenomic analysis tool. Rickettsia-specific PCR was used for the characterization of rickettsial species. Almost full length of 16S rDNA was amplified in order to characterize unclassified bacterial sequences obtained in I. persulcatus female samples. The numbers of bacterial genera identified for the tick species were 71 (I. ovatus), 127 (I. persulcatus) and 59 (H. flava). Eighteen bacterial genera were commonly detected in all tick species. The predominant bacterial genus observed in all tick species was Coxiella. Spiroplasma was detected in Ixodes, and not in H. flava. PCA revealed that microbial populations in tick salivary glands were different between tick species, indicating that host specificities may play an important role in determining the microbial complement. Four female I. persulcatus samples contained a high abundance of several sequences belonging to Alphaproteobacteria symbionts. This study revealed the microbial populations within the salivary glands of three species of ticks, and the results will contribute to the knowledge and prediction of emerging tick-borne diseases.     

Salivary glands in Cicadidae (Hemiptera: Cicadoidea): comparative morphology, ultrastructure, and their phylogenetic significance

The present investigation provides information on gross morphology and ultrastructure of salivary glands of species in Cicadidae in detail. The structure of the salivary glands of 11 representative species from 10 genera belonging to three subfamilies of Cicadidae was studied using light microscopy and transmission electron microscopy. In the examined species, the salivary glands are paired structures, and each of which is comprised of a principal gland (pg) and an accessory gland (ag). The pg is divided into anterior and posterior lobes, and both of which consist of numerous long digitate lobules. The lobules at the base of the long digitate lobules of posterior lobe are greatly short; here, we named as “short lobules.” All the lobules vary in size, disposition, length, and shape. The anterior lobe and posterior lobes are connected by an anterior–posterior duct (apd). Two efferent salivary ducts (esd), derived from corresponding posterior lobes, fuse to form a short common duct which enters into the saliva syringe. The ag is composed of a greatly tortuous and folded accessory salivary tube, a gular gland (gg) constituting of several acini, and an accessory salivary duct (asd). The asd joins the esd at the place where the latter emergences. Constituents and arrangement of the salivary glands, the number and shape of the long digitate lobules in the anterior and posterior lobes, and the visibility of the apd were promising characters for the taxonomic and phylogenetic analysis of Cicadoidea. The variations of secretory granules in size, shape, and electron density in lobule cells of pg of Platypleura kaempferi probably indicating different materials are synthesized. The absence of the infoldings of basal plasma membrane in the basal area of the cells and the presence of electron-lucent vesicles in the cytoplasm of the gg cells of P. kaempferi might suggest that the secretions of gg are more watery.     

Prevalence of enlarged salivary glands in wild populations of Glossina pallidipes in Kenya,with a note on the ultrastructure of the affected organ

Enlarged salivary gland was found to be widespread among wild populations of Glossina pallidipes in Kenya. The incidence of this abnormality varied from 0.9% in Meru National Park in Central Kenya to 5.4% in the Shimba hills area on the Kenya coast. Ultrastructurally, the enlarged glands were multinucleated with lumen reduced substantially in size. A large number of viruses filled both the lumen and the broken pieces of epithelial cytoplasm. In some cases Trypanosoma brucei trypanosomes were seen in the lumen of the enlarged glands. The epithelial cytoplasm was heavily vacuolated. Comment is made on the suitability of the diseased flies as transmitters of T. brucei.     

Musculature of the ovipositor of Lenitovena trigona (Matsumura) (Diptera, Tephritidae) with reference to the larval saprophagy

The larvae of most Tephritidae are endobiotic in various living plants and are therefore convenient objects for analysis of the associations of this dipteran family with seed plants. The structure of the sclerites and musculature of the ovipositor of Lenitovena trigona (Matsumura) a Far Eastern tephritid of the tribe Acanthonevrini with initially saprobiont larva, was investigated to facilitate understanding of the morphological changes in the adults associated with larval shift from saprophagous to herbivorous habit. Differences between the ovipositor of L. trigona and those of species of the genera Urophora, Ceratitis, and Rhagoletis with endophytic larvae have been found; the ovipositor musculature of these genera has been described by Dean (1935), Nanna (1938), and Berube and Zacharuk (1983).     

Comparative ultrastructure of the salivary glands of two phytopathogen vectors,the beet leafhopper,Circulifer tenellus (Baker), and the corn leafhopper,Dalbulus maidis DeLong and Wolcott (Homoptera : Cicadellidae)

The salivary glands of 2 leafhoppers, Circulifer tenellus and Dalbulus maidis (Homoptera : Cicadellidae) were examined by light and electron microscopy. Centrally located and occupying both the head and thorax, the salivary glands consist of 2 paired parts, the accessory glands and the principal glands. In C. tenellus and D. maidis, the accessory glands are large, multicelled lobes that lie anterior to the principal gland. They join the principal glands near the common salivary duct-gland junction via a thinner tubular duct. The principal glands of both species consist of large binucleate cells that differ in cytology and arrangement. These cells are easily distinguished by unique staining characteristics. Circulifer tenellus salivary gland cells are arranged in 2 lobes, the anterior lobe, made up of 3 concentric rings around the salivary duct and the posterior lobe, arranged in a loose pyramid extending above the foregut. Dalbulus maidis glands are similarly organized around the salivary duct.     

Morphological changes in the cephalic salivary glands of females and males of <Emphasis Type="Italic">Apis mellifera</Emphasis> and <Emphasis Type="Italic">Scaptotrigona postica</Emphasis> (Hymenoptera,Apidae)

The cephalic salivary glands of some species of bees are exclusive and well developed only in Apinae. These glands were studied with light and scanning electron microscopy in workers, queens and males from the honey bee Apis mellifera, and the stingless bee Scaptotrigona postica in different life phases. The results show that the cephalic salivary glands are present in females of both the species, and in males of S. postica. Nevertheless, they are poorly developed in young males of A. mellifera. In both species, gland growth is progressive from the time of emergence to the oldest age but, in A. mellifera males, the gland degenerates with age. Scanning electron microscopy shows that the secretory units of newly emerged workers are collapsed while in older workers they are turgid. Some pits on the surface of the secretory units correspond to open intercellular spaces. The possible functions of these glands in females and males of both species are discussed.     

Distribution,host plant affiliation,phenology, and phylogeny of walnut‐infesting Rhagoletis flies (Diptera: Tephritidae) in Mexico

Many taxa of Nearctic origin have diversified in the subtropical highlands of Mexico. In particular, flies in the genus Rhagoletis have undergone episodes of isolation and gene flow during Pleistocene glaciations and post‐glacial times that have produced lineage differentiation and reproductive isolation. To reach a better understanding of the phylogeography of the genus Rhagoletis, a host plant survey of the walnut‐infesting Rhagoletis suavis species group was conducted across sixteen states comprising 34 different collecting sites in Mexico over a 9‐year period. Five species of Juglans were found to be infested by three species of walnut‐attacking Rhagoletis flies. Several species of parasitoids were also recovered from collections, but in contrast to their walnut fly hosts, they revealed little evidence for host or geographic subdivision. There was no consistent difference in mean eclosion time between walnut fly species or populations associated with different host walnuts in Mexico, unlike the case for other Rhagoletis species, in which allochronic isolation arising from variation in diapause timing is a major ecological adaptation, reproductively isolating flies. We compare the distribution of R. suavis flies in Mexico with those of other Rhagoletis species attacking hawthorns and cherries, and discuss its implications for population divergence and speciation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 765–779.     

Evidence that developmental changes in type III acini in the tickAmblyomma hebraeum (Acari: Ixodidae) are initiated by a hemolymph-borne factor

During feeding, certain cells in the salivary gland type III acini of the ixodid tickAmblyomma hebraeum Koch undergo major developmental changes. We induced many of these changes in the ablumenal interstitial cells (AbIC), adlumenal interstitial cell (AdIC), and f-cells of type III acini, by transplanting the salivary gland of the unfed female to the hemocoel of a feeding female. In transplants, AbICs enlarged and formed a labyrinth of extracellular spaces. Extensions of AbICs pushed into the AdIC. Autophagic vacuoles were common in AbICs. The f-cells also enlarged and developed autophagic vacuoles. Complex interdigitation occurred between the f-cells and the AbIC. In transplants, the labyrinth was not as extensive as that of fed unoperated females or of operated females. The AdIC, AbIC, and f-cells did not undergo as extensive a development in unoperated fed males as the same cells did in unoperated fed females. In males AbICs did not develop an extensive labyrinth, and the f-cells did not develop beyond a secretory phase. No autophagic vacuoles were observed in any of these cells. When male salivary glands were transplanted into feeding females, AdIC, AbICs and f-cells developed an ultrastructure similar to the same cells in female transplants. Cells from salivary glands of unfed females cultured for 2 days in TC medium 199 resembled the same cells from control unfed salivary glands. The selectivity of these changes supports the conclusion that a hemolymph-borne salivary gland development factor initiated this development.     

A high‐throughput detection method for invasive fruit fly (Diptera: Tephritidae) species based on microfluidic dynamic array

Invasive species can be detrimental to a nation's ecology, economy and human health. Rapid and accurate diagnostics are critical to limit the establishment and spread of exotic organisms. The increasing rate of biological invasions relative to the taxonomic expertise available generates a demand for high‐throughput, DNA‐based diagnostics methods for identification. We designed species‐specific qPCR primer and probe combinations for 27 economically important tephritidae species in six genera (Anastrepha, Bactrocera, Carpomya, Ceratitis, Dacus and Rhagoletis) based on 935 COI DNA barcode haplotypes from 181 fruit fly species publically available in BOLD, and then tested the specificity for each primer pair and probe through qPCR of 35 of those species. We then developed a standardization reaction system for detecting the 27 target species based on a microfluidic dynamic array and also applied the method to identify unknown immature samples from port interceptions and field monitoring. This method led to a specific and simultaneous detection for all 27 species in 7.5 h, using only 0.2 μL of reaction system in each reaction chamber. The approach successfully discriminated among species within complexes that had genetic similarities of up to 98.48%, while it also identified all immature samples consistent with the subsequent results of morphological examination of adults which were reared from larvae of cohorts from the same samples. We present an accurate, rapid and high‐throughput innovative approach for detecting fruit flies of quarantine concern. This is a new method which has broad potential to be one of international standards for plant quarantine and invasive species detection.     

Two digeneans from the needlefish Ablennes hians in Kuwait and the description of a new genus and species,Neohaplosplanchnus ablennis (Haplosplanchnidae)

Two digeneans are reported from the intestine of the needlefish Ablennes hians (Valenciennes, 1846) from Kuwait. Prolecitha obesa Manter, 1961 is redescribed and an eversible acetabulum and a sinus-sac, not previously reported, are found. The synonymy of P. beloni, Lobatovitelliovarium fusiforme and Follicovitellosum indicum with P. obesa is confirmed and Cryptodiscus indicus is added to the list. Neohaplosplanchnus ablennis n. g., n. sp. is characterized by having a large acetabulum with a longitudinal opening bearing two auricular appendages at its posterior end and by having ‘salivary’ glands. The new genus is attached to the family Haplosplanchnidae, subfamily Pseudoschikhobalotrematinae, and differentiated from other genera of the family. The subfamily Pseudoschikhobalotrematinae is redefined and a key is provided to its genera.     

A putative kinase-related protein (PKRP) from Plasmodium berghei mediates infection in the midgut and salivary glands of the mosquito

The completion of the Plasmodium (malaria) life cycle in the mosquito requires the parasite to traverse first the midgut and later the salivary gland epithelium. We have identified a putative kinase-related protein (PKRP) that is predicted to be an atypical protein kinase, which is conserved across many species of Plasmodium. The pkrp gene encodes a RNA of about 5300 nucleotides that is expressed as a 90 kDa protein in sporozoites. Targeted disruption of the pkrp gene in Plasmodium berghei, a rodent model of malaria, compromises the ability of parasites to infect different tissues within the mosquito host. Early infection of mosquito midgut is reduced by 58-71%, midgut oocyst production is reduced by 50-90% and those sporozoites that are produced are defective in their ability to invade mosquito salivary glands. Midgut sporozoites are not morphologically different from wild-type parasites by electron microscopy. Some sporozoites that emerged from oocysts were attached to the salivary glands but most were found circulating in the mosquito hemocoel. Our findings indicate that a signalling pathway involving PbPKRP regulates the level of Plasmodium infection in the mosquito midgut and salivary glands.     

Development and ageing of the salivary glands of adult female Aedes aegypti (L.) and Aedes togoi (Theobald) mosquitoes (Diptera : Culicidae)

Histological sections of the salivary glands of adult female Aedes aegypti and Aedes togoi (Diptera : Culicidae), varying in age from less than 1 day to 48 days after emergence were examined by light microscopy. Following emergence, the glands underwent morphological differentiation and also enlarged as secretory product accumulated, especially in the posterior regions. Development was complete within about 3 days (A. aegypti) or 7 days (A. togoi). Ageing, which began between 10 and 15 days after emergence in both species, predominantly affected the posterior regions of the glands. Regression, involving loss of stored secretion and cytological evidence of reduced protein synthesis, was accompanied by degenerative changes including substantial cytoplasmic vacuolation and increased prominence of large cyst-like structures. Although, in general, both regression and degeneration increased with time, there was marked variation between one gland and another in the speed with which ageing changes progressed.     

Use of fluorescein-labelled lectin binding of salivary glands to distinguish between Anopheles stephensi and An. albimanus species and strains

Fluorescein isothiocyanate (FITC)-conjugated lectins were used as markers to distinguish different carbohydrate moieties on the surface of the salivary glands of Anopheles stephensi and An. albimanus species and strains. Six FITC-conjugated lectins showed interspecific differences between the two Anopheles species, and intraspecific variations between An. stephensi strains. Both fluorescence and electron microscopy demonstrated clear binding of these lectins. The salivary glands of Plasmodium-infected and uninfected An. stephensi were also examined in order to determine whether salivary gland surface carbohydrates change following infection. However, no variations were observed and it appears that the surface sugars are involved in vector tissue recognition by Plasmodium sporozoites.     

Epidermal glands in cordylid lizards,with special reference to generation glands

We investigated inter‐ and intraspecific variation in epidermal gland characteristics in cordylid lizards. Our particular interest was whether a causal relationship exists between the presence of generation glands and lifestyle, i.e. in rock‐dwelling or ground‐dwelling lizards. We established that both femoral and generation glands are always present in adult males, but that species can be divided into three categories on the basis of the presence of these glands in adult females: both femoral and generation glands absent; femoral glands present, but generation glands absent; and both femoral and generation glands present. The absence of epidermal glands in females appears to be the basal condition in the Cordylidae. All cordylid species are sexually dimorphic as far as generation gland number is concerned, with females having consistently less glands than males. Gland number in females is strongly affected by climate, being lower in cooler compared with warmer environments. In males, there is no clear geographical pattern, although in some clades males of high‐altitude species have more generation glands than males of species occurring at lower altitudes. At least four of the five ground‐dwelling species in the family display unique generation gland characteristics, compared with rock‐dwelling species, reflecting the continued importance of generation glands in terrestrial environments. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 312–324.     

Effect of O-allyl-hydroxy amino acids on protein synthesis and secretion by cultured fat body and salivary glands in the fruit fly Ceratitis capitata

• 1.1. The amino acid analogs O-allyl-tyrosine, O-allyl-threonine, O-allyl-serine and O-allyl-homoserine, have been synthesized and their effect on protein synthesis and secretion in cultured C. capitata fat body and salivary glands have been studied.
• 2.2. The analogs had an inhibitory effect on protein synthesis in both tissues. Moreover, the analogs caused a slight increase in protein secretion in the fat body in comparison to the control.
• 3.3. The intracellular transit time of protein secretion in treated and non-treated fat body was found essentially the same (about 10 min).

     

The interaction between Trypanosoma rangeli and the nitrophorins in the salivary glands of the triatomine Rhodnius prolixus (Hemiptera; Reduviidae)

The parasite Trypanosoma rangeli develops in the intestinal tract of triatomines and, particularly in species of the genus Rhodnius, invades the hemolymph and salivary glands, where subsequent metacyclogenesis takes place. Many aspects of the interaction between T. rangeli and triatomines are still unclear, especially concerning the development of the parasite in the salivary glands and how the parasite interacts with the saliva. In this work, we describe new findings on the process of T. rangeli infection of the salivary glands and the impact of infection on the saliva composition. To ensure a complete infection (intestinal tract, hemolymph and salivary glands), 3rd instar Rhodnius prolixus nymphs were fed on blood containing T. rangeli epimastigotes using an artificial feeder. After molt to the 4th instar, the nymphs were inoculated with epimastigotes in the hemolymph. The results showed that the flagellates started to invade the salivary glands by the 7th day after the injection. The percentage of trypomastigotes inside the salivary glands continuously increased until the 25th day, at which time the trypomastigotes were more than 95% of the T. rangeli forms present. The salivary contents from T. rangeli-infected insects showed a pH that was significantly more acidic (<6.0) and had a lower total protein and hemeprotein contents compared with non-infected insects. However, the ratio of hemeprotein to total protein was similar in both control and infected insects. qPCR demonstrated that the expression levels of three housekeeping genes (18S rRNA, β-actin and α-tubulin) and nitrophorins 1–4 were not altered in the salivary glands after an infection with T. rangeli. In addition, the four major nitrophorins (NPs 1–4) were knocked down using RNAi and their suppression impacted T. rangeli survival in the salivary glands to the point that the parasite burden inside the R. prolixus salivary glands was reduced by more than 3-fold. These results indicated that these parasites most likely non-specifically incorporated the proteins that were present in R. prolixus saliva as nutrients, without impairing the biosynthesis of the antihemostatic molecules.