Ventral Gland Research Articles

Differential Pheromone Sampling of the Gland of Female Heliothis Virescens Moths Reveals Glandular Differences in Composition and Quantity.

By differentially sampling the pheromone gland of females of the moth Heliothis virescens, we explored differences in pheromone on the surface, or outer distal layer(s) of the gland, and that located more proximally. For this, we used two sampling approaches, (i) a solid phase microextraction fiber rub followed by solvent extraction of residual pheromone (SPME rub/extract), and (ii) rapid solvent rinsing followed by solvent extraction of residual pheromone (rinse/extract). The SPME rub showed differences in component ratio between the dorsal and ventral gland surfaces. The rinse sampled a greater amount of pheromone than the SPME rub, sampling the whole gland surface as well as likely deeper into the gland. Compared to the other samplings, pheromone in the rinse was depleted in the minor component; consequently, the corresponding residual extract was highly enriched in the minor component. Further rinses of the gland yielded only small amounts of pheromone, with a similar component ratio as the first rinse, suggesting that the residual pheromone was less accessible and required extraction in solvent to be liberated. Sampling over the photoperiod showed that the more volatile minor component was depleted (relative to the major component) on the surface/outer cuticle over the period when females called. Together, these data suggest that the pheromone is stored, at least in part, on and in the gland cuticle and that distinct pools may be transported to different topographic regions. Females fed with a stable isotope tracer, incorporated label into pheromone in the gland very rapidly, with the labeled pheromone appearing on the gland surface ca. 1min later.

First Report of <I>Ptycholaimellus macrodentatus</I> (Timm, 1961) (Nematoda: Chromadorida) from Indian Coast

The first reporting of Ptycholaimellus macrodentatus from Indian coast is being made given due importance on the comparative morphometrics. The specimens under the present study have been found to attain a maximum length up to 1111 μm, are endowed with a long s-shaped dorsal tooth, collar enclosing the labial rugae, a groove at the base and double oesophageal bulb. All the specimens studied had a long ventral gland originated far behind of the oesophagus and opened into a small slit. This species was previously reported from the coastal Bangladesh and off the Kenyan water.

A Description of the Skin Glands and Cloacal Morphology of the Plethodontid SalamanderKarsenia koreana

The skin glands and cloacal morphology of the Korean crevice salamander, Karsenia koreana, were similar to those of other plethodontids. The skin contained mucous, granular, and modified granular glands in varying frequencies and sizes. Males had sexually dimorphic glands in the skin of the chin (mental glands) and the dorsal tail base (caudal courtship glands). On the ventral surface of the tail base, modified granular glands were sexually dimorphic in size, with male glands larger than those in females. The cloacal glands in males, as in other plethodontids, consisted of four eosinophilic gland clusters (dorsal pelvic glands, lateral pelvic glands, caudal pelvic glands, and vent glands) and three basophilic glands (anterior ventral glands, posterior ventral glands, and Kingsbury's glands). In females, the only cloacal gland was the spermatheca, which, as in other plethodontids, was a compound tubulo-alveolar gland in the roof of the cloaca.

Two new species of Chromadoridae (Chromadorida: Nematoda) from the East China Sea.

Two new species of Chromadoridae, a family of free-living marine nematodes, are described from intertidal sediments of the East China Sea. Ptycholaimellus pirus sp. nov. is characterized by having a cuticle with six longitudinal rows of double dots and long somatic setae, relatively long cephalic setae, a pear-shaped terminal pharyngeal bulb occupying less than 30% of pharyngeal length, and an elongate conical tail. The new species is distinguished from all related species by the unique character of the cuticle, with six longitudinal rows of horizontal double dots, and the pear-shaped terminal pharyngeal bulb. Hypodontolaimus ventrapophyses sp. nov. is characterized by having a cylindrical body with a slightly expanded anterior end and a conical tail, a homogeneous cuticle with lateral differentiation of two longitudinal rows of larger dots, a well developed pharynx with oval-shaped buccal bulb and terminal bulb, and a large ventral gland. Males have slender, strongly curved spicules and a gubernaculum with a ventral apophysis, and precloacal supplements are absent. The new species differs from all related species in this genus by the structure of the gubernaculum, which has a ventral apophysis.

Photoperiod and aggression induce changes in ventral gland compounds exclusively in male Siberian hamsters

Chemical communication is a critical component of social behavior as it facilitates social encounters, allows for evaluation of the social partner, defines territories and resources, and advertises information such as sex and physiological state of an animal. Odors provide a key source of information about the social environment to rodents; however, studies identifying chemical compounds have thus far focused primarily on few species, particularly the house mouse. Moreover, considerably less attention has been focused on how environmental factors, reproductive phenotype, and behavioral context alter these compounds outside of reproduction. We examined the effects of photoperiod, sex, and social context on chemical communication in the seasonally breeding Siberian hamster. We sampled ventral gland secretions in both male and female hamsters before and after an aggressive encounter and identified changes in a range of volatile compounds. Next, we investigated how photoperiod, reproductive phenotype, and aggression altered ventral gland volatile compound composition across the sexes. Males exhibited a more diverse chemical composition, more sex-specific volatiles, and showed higher levels of excretion compared to females. Individual volatiles were also differentially excreted across photoperiod and reproductive phenotype, as well as differentially altered in response to an aggressive encounter. Female volatile compound composition, in contrast, did not differ across photoperiods or in response to aggression. Collectively, these data contribute to a greater understanding of context-dependent changes in chemical communication in a seasonally breeding rodent.

Pseudolella major sp. nov. (Axonolaimidae, Nematoda) from the intertidal zone of the East China Sea

A new species of free-living nematode, Pseudolella major sp. nov. is described from the intertidal mudflats of Ximen Island in the East China Sea. Pseudolella major sp. nov. is characterized as follows: body length ~1 300 μm; short cephalic setae, 2–3 μm long; amphidial fovea loop-shaped with elongated ventral branch; ventral branch 50–60 μm long and extending past the base of buccal cavity; buccal cavity cylindrical with arching or spherical base; three heavy outwardly-curving odontia with blunt tips located at anterior of buccal cavity; pharynx short with posterior bulb; ventral gland cell elongate oval-shaped, located posterior to pharyngo-intestinal junction; excretory pore situated at the level of the middle of buccal cavity; tail conical to cylindrical; spicules arched, with double-cephalate proximal end; gubernaculum with a strong dorsal caudal apophysis.

Ultrastructure of the mental gland of the Red‐Backed Salamander, Plethodon cinereus (Amphibia: Plethodontidae)

AbstractMental glands are sexually dimorphic glands found in the skin of the submandibular region in males of many species in the salamander family Plethodontidae. These glands have been demonstrated to secrete pheromones that increase female receptivity to courtship and mating. A number of studies exist on the morphology of mental glands at the light microscopy level, but ultrastructural studies on the glands exist for only two species, Eurycea quadridigitata and Hydromantes italicus. In this study, ultrastructure of the mental gland is described from seasonal samples of the eastern North American plethodontid Plethodon cinereus. The mental glands are most hypertrophied in males examined in mating condition (i.e. sperm in their Wolffian ducts) in October and April. In these specimens, 6‐ to 8‐μm electron‐dense secretory vacuoles are found in the apical cytoplasm (October) or throughout the entire epithelial cells (April). Mental glands from June and August contain only condensing vacuoles, and the cytoplasm is otherwise packed with stacks of rough endoplasmic reticulum. The ultrastructure of the mental gland of P. cinereus agrees with earlier descriptions for E. quadridigitata and H. italicus. Two other sexually dimorphic skin glands, the caudal courtship gland and the cloacal vent gland, were previously examined from males in this sample of P. cinereus. Although all three glands show similarities in histology and histochemistry at the light microscopy level, they are dissimilar in ultrastructure. Whereas the secretory vacuoles of mental glands are uniformly electron dense, those of caudal courtship glands are smaller (1.2–1.5 μm), oblong and biphasic, and vent glands have spherical biphasic secretory vacuoles (1.8–2.1 μm). This indicates a difference in secretory product and function for the three glands and needs further investigation. Whether other plethodontids show similar variation among sexually dimorphic glands is another topic for future research.

Magnetic resonance imaging anatomy of the feline salivary glands

The aim of the study was to define anatomical characteristics of feline salivary glands using magnetic resonance imaging (MRI) and to describe landmarks for their reliable identification. Heads of 37 adult cats without signs of diseased salivary glands on clinical examination or history were examined. In cats included in the prospective part of the study, the MRI study was completed within one hour after euthanasia (n=16). In the retrospective part, previously performed MRI studies were evaluated (n=21). The prospective part of the study included the following standardized sequences: T2-weighted (T2W) turbo spin echo (TSE), T2W fat-suppressed TSE and proton density weighted (PDW) TSE images in a transverse plane as well as T1-weighted (T1W) fast field echo (FFE) in the transverse, sagittal and dorsal planes. In the retrospective part, T2W TSE and T1W TSE transverse images pre- and post-contrast were analyzed. Initially, identification and delineation of the salivary glands from surrounding tissue was assessed. Anatomical structures of the head were then identified and defined as landmarks. The dimensions of the glands were measured on T2W TSE images and the signal intensity in relation to that of fat and muscle was described using all sequences. In total, 95.9% of the parotid glands and 100% of the mandibular glands could be visualized on T1W TSE and FFE images and on T2W TSE images. Additionally, 93.3% of the zygomatic glands were identified on T2W TSE sequences and 82.5% on T1W TSE and FFE images. The ventral buccal glands could be demarcated in some sequences (T2W TSE: 51.4%, T1W TSE and FFE: 18.9%). Anatomical landmarks facilitated gland identification. Comparing the size of the salivary glands of both groups revealed differences of up to 2mm. Both the large salivary glands (Glandula [Gl.]. parotis and Gl. mandibularis) and the small salivary glands (Gl. zygomatica and Gl. buccalis ventralis) of the cat can be reliably identified on MRI images.

Multimodal defensive strategies in larvae of two Hemichroa sawfly species

The two European sawfly species in the genus Hemichroa are a contrast in behaviour and appearance, since H. crocea is gregarious and brightly coloured, whereas H. australis is solitary and cryptic. Here, their defensive strategies are compared by integrating further components. In both species, ventral glands are minute, and no distinctive volatiles were detected by chemical analysis; hence, these exocrine glands are probably irrelevant in defence. Ethanol extracts of body parts were feeding deterrent to ant workers of Myrmica rubra, especially the integument of H. australis which was more deterrent than that of H. crocea. Single, living larvae of H. crocea were also attacked more frequently by ants. In contrast, single larvae of H. crocea are reluctantly taken by the bird Parus major that readily feeds on H. australis. The larvae of both species jerk their abdomen to physically defend themselves and/or to increase their (visual) warning signal (H. crocea). The larvae of H. crocea can scratch the host plant leaf with the tip of their abdomen to produce a sound assumed to convey information in intraspecific communication. However, this behaviour was also elicited from H. australis, when disturbed, which suggests that it may have another function. The defensive strategy is multimodal in both species. The principal differences are the reliance on gregariousness in H. crocea, as opposed to the use of integumental chemicals in H. australis.

Abstract LB-072: The N-Myc transcriptional program driving the neuroendocrine prostate cancer phenotype

Abstract Although neuroendocrine prostate cancer (NEPC) rarely arises de novo, up to 30% of patients with prostate adenocarcinoma (PCa) develop NEPC features in later stages of their disease as a mechanism of treatment resistance to hormonal therapies including abiraterone and enzalutamide. NEPC is clinically more aggressive than PCa, commonly metastases to visceral organs such as liver and brain, and can be suspected in patients with progressive disease and a disproportionately low serum PSA. There is currently no effective therapy for NEPC, and most patients with NEPC survive less than one year. The development of novel treatment strategies for patients with NEPC represents a significant clinical unmet need. We have previously discovered significant over-expression and gene amplification of AURKA (encoding Aurora-A) and MYCN (encoding N-Myc) in NEPC as compared to prostate adenocarcinoma. As in neuroblastoma, N-Myc interacts with Aurora-A in NEPC which leads to a co-stabilization of both proteins that is targetable with allosteric inhibitors of Aurora A. We have also shown that ectopic expression of N-Myc induces neuroendocrine transformation of prostate adenocarcinoma cells. However, the molecular mechanisms that underlie N-Myc driven NEPC phenotype have yet to be characterized. To address this, we performed RNA-sequencing (RNAseq) and ChIP-sequencing from multiple stable prostate adenocarcinoma cells with and without N-Myc over-expression. We have identified a signature of N-Myc deregulated genes that are both biologically and clinically relevant. Based on RNAseq data from 128 clinical samples (17 NEPC, 10 castrate resistant prostate cancer 68 prostate adenocarcinoma patient tumors and 33 matched benign prostate samples) we found that majority (70%) of the N-Myc deregulated genes identified in our in vitro models distinguish the NEPC from PCa tumor samples. Based on GSEA and pathway analysis we found that N-Myc induces a profile enriched in pro-metastatic, dedifferentiation and Polycomb Repressive Complex deregulated genes and dramatically reduces AR signaling. Furthermore we show that N-Myc is recruited to AR-bound enhancers of AR target genes. To further determine the role of N-Myc in driving the NEPC phenotype we have generated transgenic mice that carry an integrated MYCN gene behind a lox-stop-lox (LSL) cassette at the ROSA26 locus, a floxed Pten locus and a tamoxifen-activated Cre recombinase driven by Tmprss2. N-Myc over-expression in the context of Ptenfl/+ leads to focal high levels of activated AKT pathway that accompany mouse high grade prostatic intraepithelial neoplasia (mHGPIN) at 3 months post-induction and other clinically relevant molecular changes. Littermates that harbor Ptenfl/+ alone do not display mHGPIN or AKT activation. In the context of Pten homozygous loss (Ptenfl/fl), N-Myc is associated with diffuse mHGPIN in the ventral and dorsolateral prostate lobes and irregular gland borders, nuclear atypia and high levels of AKT activity at 3 months (MYCN homozygous) or 6 months (MYCN heterozygous) post-induction. In conclusion, our findings support the role of N-Myc as one of the drivers of the NEPC phenotype and have the potential to ultimately lead to the identification of a new class of disease specific biomarkers and therapeutic alternatives for this aggressive subgroup of prostate cancer. Citation Format: Etienne Dardenne, Kaitlyn Gayvert, Adeline Berger, Andrea Sboner, Brian Robinson, Kenneth Hennrick, Juan Miguel Mosquera, Cynthia Cheung, Martin Eilers, Himisha Beltran, Mark A. Rubin, Olivier Elemento, David S. Rickman. The N-Myc transcriptional program driving the neuroendocrine prostate cancer phenotype. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-072. doi:10.1158/1538-7445.AM2015-LB-072

Spatial chemo-profiling of hypericin and related phytochemicals in Hypericum species using MALDI-HRMS imaging.

Advanced analytical imaging techniques, including matrix-assisted laser desorption/ionization high-resolution mass spectrometry (MALDI-HRMS) imaging, can be used to visualize the distribution, localization, and dynamics of target compounds and their precursors with limited sample preparation. Herein we report an application of MALDI-HRMS imaging to map, in high spatial resolution, the accumulation of the medicinally important naphthodianthrone hypericin, its structural analogues and proposed precursors, and other crucial phytochemical constituents in the leaves of two hypericin-containing species, Hypericum perforatum and Hypericum olympicum. We also investigated Hypericum patulum, which does not contain hypericin or its protoforms. We focused on both the secretory (dark glands, translucent glands, secretory canals, laminar glands, and ventral glands) and the surrounding non-secretory tissues to clarify the site of biosynthesis and localization of hypericin, its possible precursors, and patterns of localization of other related compounds concomitant to the presence or absence of hypericin. Hypericin, pseudohypericin, and protohypericin accumulate in the dark glands. However, the precursor emodin not only accumulates in the dark glands but is also present outside the glands in both hypericin-containing species. In hypericin-lacking H. patulum, however, emodin typically accumulates only in the glands, thereby providing evidence that hypericin is possibly biosynthesized outside the dark glands and thereafter stored in them. The distribution and localization of related compounds were also evaluated and are discussed concomitant to the occurrence of hypericin. Our study provides the basis for further detailed investigation of hypericin biosynthesis by gene discovery and expression studies.

A new species of free-living marine nematode (Nematoda: Chromadoridae) from the East China Sea.

A new species of free-living marine nematodes, Ptycholaimellus longibulbus sp. nov., is described from the East China Sea. Ptycholaimellus longibulbus sp. nov. is characterized by having body length of about 1100-1400 μm, cephalic seta 9 µm long (half a head diameter), a relatively long double posterior pharyngeal bulb occupying 44-49% of pharyngeal length, a voluminous ventral gland with a large ampulla, cuticle with transverse rows of punctations and lateral differentiation with two longitudinal rows of thick dots, relatively long spicules 45-55 μm long, an arcuate gubernaculum 25 µm long, and a conico-cylindrical tail with a distinct long finger-like spinneret. A key to species of Ptycholaimellus is given.

Histological and ultrastructural reconstruction of ventral epidermal glands of Spio (Polychaeta, Spionidae, Annelida)

With present study, we confirm that the ventral structures on anterior and middle chaetigers of two species of Spio are special kind of intraepidermal multicellular glands. The general anatomy and coherence morphology of these ventral epidermal glands (VEGs) were 3D-reconstructed based on semithin section series. Specific anatomical characters were explored using electron microscopy, such as scanning electron microscopy for characterization of gland pores and transmission electron microscopy for investigation into cytoanatomical details. The VEGs are tubular or acinar; their pores are spherical or lens-shaped. The glands consist of three cell types: secretory cells, sheath cells and canal cells, forming and strengthening the short gland duct and the pore region. The secretory cells are tightly packed into a single-layered, curved glandular epithelium. Secretory cells are separated from each other by thin projections of interstitial sheath cells. The apices of the secretory and sheath cells surround a tubular or vase-shaped extracellular space, the reservoir. The reservoir is traversed by microvilli of the secretory and sheath cells. Two sorts of microvilli characterize the apex of secretory cells: slender, elongated ones located at the periphery (outer microvilli), and shorter but thicker ones, arranged in a distinct collar in the centre (inner microvilli). Secretion, encased in regular secretory granules and discharged only at the apex’ centre, is guided through the space enclosed by the collar of inner microvilli. Though also consisting of numerous cells, the VEGs of Spio spp. are not comparable to parapodial glands described in other spionid taxa since they remain in a strictly intraepidermal position, are distant from parapodia and contain sheath cells. Nonetheless, the VEGs are very helpful for taxonomic work on representatives of the genus Spio and closely related genera.

Cloacal Anatomy of the Male Carpathian Newt,Lissotriton montandoni(Amphibia, Salamandridae), in the Breeding Season

This study presents the first light microscopy-based description of the cloacal anatomy of male Carpathian newts (Lissotriton montandoni). This European newt species hybridizes with its sister species, the smooth newt (L. vulgaris), despite a high level of prezygotic isolation. The goal of the study was to ascertain possible anatomical differences in cloacal anatomy, especially pheromone and spermatophore producing glands, which might potentially affect reproductive isolation between L. montandoni and L. vulgaris. The cloaca of L. montandoni males consists of the cloacal tube, cloacal chamber, pseudopenis, and aggregations of cloacal glands. Four main types of cloacal glands were recognized. Pheromone-producing dorsal glands are of two types due to differences in their secretory epithelium: cuboidal and high prismatic. The remaining glands: ventral, pelvic, and Kingsbury's glands, are most likely involved in the synthesis of spermatophore components. Two distinct groups of ventral glands were identified: posterior and anterior ventral glands. In comparison with L. vulgaris, no evident differences were found that could potentially affect courtship pheromone synthesis by dorsal glands or the base and the cap of the spermatophore produced by the remaining cloacal glands.

Seven new species and one new species record of Sabatieria (Nematoda: Comesomatidae) from the continental slope of New Zealand.

Sabatieria is the most abundant nematode genus on the upper continental slope of New Zealand but no Sabatieria species have yet been recorded/described from the region's deep-sea habitats. The present study describes seven new and one known species of this genus from the continental margin of New Zealand. S. bitumen Botelho et al. 2007 was originally described from the South Atlantic Ocean, and is recorded from the first time in the Pacific Ocean. Sabatieria challengerensis sp. n. is characterised by a combination of short cephalic setae, large fovea amphidialis with 3 turns, short arcuate spicules without distal hook, and short tail with cylindrical proximal portion and blunt, rounded distal portion. Sabatieria parapraedatrix sp. n. is characterised by having a slender body, cuticle with striations resulting from fusion of every second lateral row of dots,fovea amphidialis with 2.0-2.5 turns, spicules with distal hook, and short conico-cylindrical tail. Sabatieria bubulba sp. n. is characterised by the presence of a large muscular pharyngeal bulb, secretory-excretory system with large ventral gland at level of intestine and with cuticularised pore opening. Sabatieria exculta sp. n. is characterised by having a slender body, cuticle with faint annulations resulting from fusion of every second or third lateral row of dots, short cephalic setae, a large ventral gland, and long, narrow gubernacular apophyses. Sabatieria balbutiens sp. n. is characterised by having a dorsally-directed mouth opening and assymetrical mouth cavity and spicules with small distal hook. Sabatieria pumila sp. n. is characterised by the combination of short body length, short cephalic setae, spicules with distal hook and short distal lamella, and 8-9 precloacal supplements. Sabatieria bathycopia sp. n. is characterised by having a stout body, short cephalic setae, curved gubernaculum, and spicules with swollen, lightly cuticularised distal tip.

Invertebrate and avian predators as drivers of chemical defensive strategies in tenthredinid sawflies.

BackgroundMany insects are chemically defended against predatory vertebrates and invertebrates. Nevertheless, our understanding of the evolution and diversity of insect defenses remains limited, since most studies have focused on visual signaling of defenses against birds, thereby implicitly underestimating the impact of insectivorous insects. In the larvae of sawflies in the family Tenthredinidae (Hymenoptera), which feed on various plants and show diverse lifestyles, two distinct defensive strategies are found: easy bleeding of deterrent hemolymph, and emission of volatiles by ventral glands. Here, we used phylogenetic information to identify phylogenetic correlations among various ecological and defensive traits in order to estimate the relative importance of avian versus invertebrate predation.ResultsThe mapping of 12 ecological and defensive traits on phylogenetic trees inferred from DNA sequences reveals the discrete distribution of easy bleeding that occurs, among others, in the genus Athalia and the tribe Phymatocerini. By contrast, occurrence of ventral glands is restricted to the monophyletic subfamily Nematinae, which are never easy bleeders. Both strategies are especially effective towards insectivorous insects such as ants, while only Nematinae species are frequently brightly colored and truly gregarious. Among ten tests of phylogenetic correlation between traits, only a few are significant. None of these involves morphological traits enhancing visual signals, but easy bleeding is associated with the absence of defensive body movements and with toxins occurring in the host plant. Easy bleeding functions through a combination of attributes, which is corroborated by an independent contrasts test indicating a statistically significant negative correlation between species-level integument mechanical resistance and hemolymph feeding deterrence against ants.ConclusionsOur analyses evidence a repeated occurrence of easy bleeding, and no phylogenetic correlation including specific visual signals is significant. We conclude that the evolution of chemically-based defenses in tenthredinids may have been driven by invertebrate as much as by avian predation. The clear-cut visual signaling often encountered in the Nematinae would be linked to differential trends of habitat use by prey and predators. Further studies on (prey) insect groups should include visual signals and other traits, as well as several groups of natural enemies, to better interpret their relative significance and to refine our understanding of insect chemical defenses.

Identification of a new species of digenean Notocotylus malhamensis n. sp. (Digenea: Notocotylidae) from the bank vole (Myodes glareolus) and the field vole (Microtus agrestis)

Notocotylus malhamensis n. sp. is described from the caecum of the bank vole (Myodes glareolus) and the field vole (Microtus agrestis) from Malham Tarn Nature Reserve in North Yorkshire, UK. In total, 581 specimens were collected from rodents trapped at a wetland site (Tarn Fen) between July 2010 and October 2011 with a prevalence of 66·7% and mean intensity of 94·6 in the bank vole and 50% prevalence and a mean intensity of 4·3 in the field vole. This species appears to be most closely related to other previously described Notocotylus species infecting rodents in Europe but differs principally by the metraterm to cirrus sac ratio (1:1·5-1:1·2) in combination with a densely spinulated cirrus, simple caeca and a greater number of ventral glands in the lateral rows (14-17). The use of molecular differentiation was of limited use in this study due to a paucity of relevant information in the DNA sequence databases. However, the complete ITS1-5.8S rDNA-ITS2 and partial 28S gene sequences have been generated to provide a definitive tool for identification of this species in future studies. As far as we know this is the first report of a notocotylid infection in M. glareolus in the UK.

Two new free-living marine nematode species of Chromadoridae (Nematoda: Chromadorida) from the Yellow Sea, China

Two new species of free-living marine nematodes, Ptycholaimellus ocellatus sp. nov. and Prochromadorella gracilis sp. nov. from the Yellow Sea, China are described. Ptycholaimellus ocellatus sp. nov. is characterized by the presence of ocelli, an abruptly narrowing anterior cervical region, a cuticle with transverse rows of punctations, a lateral differentiation with two longitudinal rows of thick elongate dots, and voluminous ventral gland with a large ampulla. Prochromadorella gracila sp. nov. is characterized by the combination of lateral differentiations in the anterior pharyngeal region, a small conical stoma with outstretched teeth, slit-like amphidial fovea, and five pre-cloacal supplements.

Defense by Volatiles in Leaf-Mining Insect Larvae

The defense strategy of an insect toward natural enemies can include a trait that appears at first sight to contradict its defensive function. We explored phylogeny, chemistry, and defense efficiency of a peculiar group of hymenopteran sawfly larvae where this contradiction is obvious. Pseudodineurini larvae live in leaf mines that protect them from some enemies. Disturbed larvae also emit a clearly perceptible lemon-like odor produced by ventral glands, although the mine hampers the evaporation of the secretion. The mine could also lead to autointoxication of a larva by its own emitted volatiles. Citral was the major component in all Pseudodineurini species, and it efficiently repels ants. We conclude that full-grown larvae that leave their mine to pupate in the soil benefit from citral by avoiding attacks from ground-dwelling arthropods such as ants. In some species, we also detected biosynthetically related compounds, two 8-oxocitral diastereomers (i.e., (2E,6E)- and (2E,6Z)-2,6-dimethylocta-2,6-dienedial). Synthetic 8-oxocitral proved to be a potent fungicide, but not an ant repellent. The discrete distribution of 8-oxocitral was unrelated to species grouping in the phylogenetic tree. In contrast, we discovered that its presence was associated with species from humid and cold zones but absent in species favoring warm and dry environments. The former should be protected by 8-oxocitral when faced with a fungal infestation while crawling into the soil. Our work shows the importance of integrating knowledge about behavior, morphology, and life history stages for understanding the complex evolution of insects and especially their defense strategies.

New species and records of Pyrgulopsis (Gastropoda: Hydrobiidae) from the Snake River basin, southeastern Oregon: further delineation of a highly imperiled fauna

Here we describe two new species from southeastern Oregon based on morphologic and molecular (mtCOI) evidence. Pyrgulopsis fresti n. sp., commonly known as the “Owyhee hot springsnail” and long considered to be distinct and critically imperiled, lives in thermal springs along a short reach of the Owyhee River above Three Forks. This snail differs from other regional species in its squat shell; penial ornament consisting of a large, disc-shaped ventral gland; absence of a seminal receptacle; and mtCOI sequences. Pyrgulopsis owyheensis n. sp. ranges among five disjunct groups of springs in the Owyhee and Malheur river drainages and is occasionally sympatric with P. fresti. This snail is closely similar to another regional congener, P. intermedia (Tryon, 1865), but is smaller and further differentiated by its typically disjunct inner shell lip, longer and narrower penial filament, more distally positioned ventral gland of penis, and mtCOI sequences. The type locality (Owyhee Spring) population of P. owyheensis is genetically differentiated from the other geographical subunits of this species (1.5–1.8% sequence divergence) and should perhaps be managed as a separate conservation unit. New records are provided for P. intermedia which extends the range of this conservation priority species into the lower Owyhee River basin. We also show that the “Malheur springsnail,” which has been listed in various conservation-related publications and documents, is the same as P. intermedia. This study provides critical information for the conservation of springsnails in southeastern Oregon and underscores the need for additional field surveys in the region.