Ultrastructural study of anther parasitism of Ficus laevigata by Ficophagus laevigatus (Aphelenchoididae).

Transmission electron microscopy (TEM) was used to compare the ultrastructural differences between healthy male florets (anthers) and one floret parasitized by Ficophagus laevigatus in late phase C syconia of Ficus laevigata from southern Florida. Previous light-microscopic examination of paraffin-sectioned material showed that F. laevigatus-infested anthers of F. laevigata manifested as malformed, often with aberrant pollen and hypertrophied epidermal cells closest to regions containing propagating nematodes. Female florets or fig wasp-parasitized female florets were not observed to be parasitized by nematodes. Considering that plant-feeding in the Aphelenchoididae is purportedly much less specialized than in certain groups of the Tylenchomorpha, where specialized hypertrophied feeder cells are produced in response to nematode feeding, we examined the putative induced response in this unusual aphelenchoidid system with the higher resolution afforded by TEM. TEM confirmed the expression of significant epidermal cell hypertrophy of the anther and anther filament in the presence of propagating nematodes, which was expressed as cell enlargement (2-5X), fractionation of large electron-dense stores into smaller aggregates, irregularly shaped nuclei enclosed by an elongated nuclear envelope, nucleolus enlargement, increased organelle production, and apparent metabolism with increased numbers of mitochondria, pro-plastids, and endoplasmic reticulum, as well as increased thickening of the cell walls. Pathological effects were observed in adjacent cells/tissue (e.g., anther and anther filament parenchymal cells, pollen tubes, pollen, and endothecium) with apparent diminishment as the distance from propagating nematodes increased (which was also probably affected by number of nematodes). Some TEM sections captured previously undocumented ultrastructural highlights of propagating individuals of F. laevigatus.

Bursaphelenchus suri n. sp.: A second Bursaphelenchus syconial parasite of figs supports adaptive radiation among section Sycomorus figs.

The nematode genus Bursaphelenchus is a highly divergent group. This genus mainly consists of mycophagous entomophilic species, but some species have specialized as obligate or facultative plant parasites, facultative insect parasites, or exhibit feeding dimorphism (phenotypic plasticity) leading to mycophagous and predatory forms. In the present study, a new Bursaphelenchus species, B. suri n. sp. was isolated from fresh syconia (figs) of Ficus sur and is described and illustrated based on its typological characters and molecular phylogenetic status. The new species is characterized by its highly derived feeding structures found in obligate plant parasites, lip possessing a labial disc and a long and thick stylet with a long conus and extremely well-developed basal swellings. In addition, slender body of both sexes is characteristic of the species. The new species is phylogenetically and typologically closely related to B. sycophilus, i.e., these two species share the characteristic feeding structures and form a well-supported clade within the B. fungivorus group in the genus. Biologically, these two species are both isolated from fresh figs of the section Sycomorus. However, the new species differs from B. sycophilus by the length of the female post-uterine sac and the shape of the male spicule, i.e., the new species has a long post-uterine sac and spicule condylus without dorsal recurvature. Thus, the new species is the second obligate fig parasite of the genus, and the evolutionary relationship between the B. suri n. sp. and B. sycophilus clade and section Sycomorus figs is hypothesized as an example of adaptive radiation with more species to be discovered.

Molecular diversity and relationships of fig associated nematodes from South Africa.

Nematodes of figs and fig wasps have received limited attention in Africa since their discovery in 1973. Sixteen of the 25 species of native South African figs were sampled for nematode associates using molecular barcoding with three loci (SSU, LSU D2-D3 and mtCOI) and fourteen (93%) were positive for at least one nematode species. Thirty-three putative species of nematodes were identified and classified according to the loci that were amplified and successfully sequenced. Fourteen putative nematode species were classified as Aphelenchoididae, of which nine were identified as Ficophagus from four species of Ficus from the section Galoglychia (i.e., five ex F. burkei including one shared with F. natalensis, one ex F. glumosa, one ex F. lutea, and one ex F. stuhlmannii) and one species ex F. sur from the section Sycomorus. In addition, there were four nematode species classified as Schistonchus s.s. from section Galoglychia figs (i.e., one ex F. burkei, two ex F. trichopoda, and one ex F. glumosa). There was also one species of Bursaphelenchus nematode recovered from F. sur from the section Sycomorus. Sixteen putative nematode species were classified as Diplogastridae, of which eight occurred in two clades of what is currently called Parasitodiplogaster with one (P. salicifoliae) being recovered from two Ficus species in the section Urostigma (F. salicifolia and F. ingens) and seven diplogastrids being associated with six species of Ficus from the section Galoglychia (i.e., two ex F. burkei including P. sycophilon, one ex F. stuhlmannii, one ex F. burtt-davyi, one ex F. trichopoda, one ex F. abutilifolia and one ex F. sansibarica). Three Acrostichus spp., a Teratodiplogaster and a Pristionchus species were recovered from F. sur and two Teratodiplogaster spp. and Pristionchus sycomori were recovered from F. sycomorus with both Ficus species belonging to the subgenus and section Sycomorus. The identities of the previously described T. martini and Parasitodiplogaster doliostoma (= Pristionchus sp. 35) are discussed. Lastly, there was a panagrolaimid identified from F. petersii.

Nematode epibionts on skin of the Florida manatee, Trichechus manatus latirostris.

A survey for the presence of nematodes on the skin of the native Florida manatee, Trichechus manatus latirostris from Crystal River, Florida was conducted during annual manatee health assessments. A putative isolate of Cutidiplogaster manati (Diplogastridae) and two other nematodes belonging to the same family were recovered from mid-dorsal tail skin-scrapings from all sampled winter-collected healthy wild adult manatees during two successive years (2018-2019). Qualitative abundance estimates of these three species of diplogastrid nematodes suggest that an average wild Florida manatee adult might possess between 30,000 and 120,000 nematodes on its tail dorsum and that the entire body dorsum including the tail might possess 160,000-640,000 nematodes in roughly equal ratios. Attempts to culture these nematodes on a variety of different culture media were unsuccessful but examination of the mouth (stomatal) morphology suggests specialized feeding on microbes such as diatoms or predation on other nematodes. No skin lesions were observed during the 2018-2019 samplings suggesting that under normal conditions these nematodes are highly specialized free-living epibionts of the skin that are tightly bound to this niche and horizontally transferred between individual manatees in an analogous fashion to human skin mites (Demodex folliculorum and D. brevis). Molecular phylogenetic inferences using sequences of near full length SSU and D2-D3 expansion segments of LSU rRNA genes revealed a putative new morphospecies in Cutidiplogaster sister to C. manati that was monophyletic with several named Mononchoides species, and another putative new morphospecies that formed a clade with several undescribed species similar in appearance to Mononchoides as well as Tylopharyx, Eudiplogasterium, Paroigolaimella and Sachsia.

Feeding Dimorphism in a Mycophagous Nematode, Bursaphelenchus sinensis.

Phenotypic plasticity has been widely reported in animals and can drive investment in new biological characters that engender ecological adaptability. The nematode family Diplogastridae, especially Pristionchus pacificus with its dramatic stomatal (feeding) dimorphism, has become an important model system to analyze the evolutionary and developmental aspects of polyphenism. However, this plasticity has not been confirmed in other nematode groups. In the present study, we experimentally examined the feeding dimorphism of a fungal feeding free-living nematode, Bursaphelenchus sinensis. In a laboratory culturing experiment, the nematode expressed dimorphism, i.e., a small proportion of the population manifested as a predatory form. This form only occurred in females and was not clearly influenced by the presence of potential prey species. In addition, the ratio of the predatory form to the mycophagous form varied among different fungal food species grown in monoculture on different culture media. The predatory form of B. sinensis was typologically similar to the monomorphic (specialized) predators belonging to the same family. However, some essential morphological characters were slightly different from the specialized predators, and their behaviours were clearly disparate, suggesting that predation in B. sinensis is derived from a different phylogenetic origin than that of the specialized predators.

Morphological and Molecular Characterization of Labrys filiformis n. sp. (Rhabditida: Tylenchidae) from Iran.

Labrys filiformis n. sp., the second species of the rare genus Labrys , was recovered from natural forests of Gilan province and is described based upon morphological and molecular characters. The new species is characterized by its smooth cuticle under light microscopy, lateral field with two incisures forming a single plain band, lip region continuous with body contour, dorso-ventrally flattened and forming four poorly prominent lobes, having a dorso-ventrally narrower protuberant labial plate laterally extended to the amphidial margins, oral area (oral plate) dorso-ventrally elongated and embedded in the labial plate with six small labial sensilla surrounding the slightly prominent oral aperture, amphidial apertures as longitudinally lemniscatic slits bordered by the labial plate extensions which are overlapped at the middle length of amphids, stylet delicate, 6 to 7 µm long, elongate weakly developed fusiform median bulb with weak valve, wide excretory pore with long and heavily sclerotized duct, offset spermatheca filled with small spheroid sperm cells, 106 to 127 µm long elongate-conoid tail with filiform distal region and finely rounded tip. Molecular phylogenetic analyses were performed using a near-full length fragment of the 18S rDNA and the D2-D3 expansion segments of the 28S rDNA using Bayesian inference and maximum likelihood methods. In the inferred phylogenetic tree with 18S rDNA, the new species has a close affinity with several isolates of the type species, Labrys chinensis . The reconstructed phylogenetic tree using partial 28S rDNA, revealed the new species is nested inside the putative monophyletic group of several populations of L. chinensis .

Morphological and molecular characteristics of Parasitodiplogaster religiosae n. sp. (Nematoda: Diplogastrina) associated with Ficus religiosa in China.

A new nematode species of the genus Parasitodiplogaster was recovered from syconia of Ficus religiosa at the Guangxiao Temple, Guangzhou, China. It is described herein as P. religiosae n. sp. and is characterised by possessing the longest and thinnest spicule of all currently described males in the genus, an elongated laterally "ε-shaped" and ventrally rhomboid-like gubernaculum, a stoma without teeth, consisting of a ring-like cheilostom with indistinct anteriolateral projections, a tube-like gymnostom and a funnel-like stegostom, monodelphic with a mean vulval position of 66%. There are three pre-cloacal and six post-cloacal male genital papillae with the arrangement P1, P2, P3, (C, P4), P5, P6d, P7, P8, P9d, Ph. This new species was easily differentiated from other members of the genus by DNA sequences of partial small subunit rRNA gene (SSU) and the D2-D3 expansion segments of the large subunit rRNA gene (LSU). Phylogenetic analysis also corroborated its reasonable placement within a well-supported monophyletic clade with other Parasitodiplogaster species and within the australis-group that includes P. australis and P. salicifoliae that are all associates of fig wasp pollinators (Platyscapa sp.) of figs of the subsection Urostigma.

Phoresy and Within-colony Transmission of Nematodes Associated with Alates of Subterranean Termites (Isoptera: Rhinotermitidae).

Termites and their nests are potential resources for a wide assemblage of taxa including nematodes. During dispersal flight events from termite colonies, co-occurring nematodes in the nest may have phoretic opportunities to use termite alates as transportation hosts. The two subterranean termite species Coptotermes gestroi (Wasmann) and Coptotermes formosanus Shiraki are both invasive and established in south Florida. Alates of both species (n = 245) were collected during dispersal flight events in 2015-2016 from six locations, of which 30 (12.2%) were associated with one or more species of nematodes. Species of Bunonema Jägerskiöld (Rhabditida: Bunonematidae), Halicephalobus Timm (Rhabditda: Panagrolaimidae), and Poikilolaimus regenfussi (Sudhaus) Sudhaus and Koch (Rhabditida: Rhabditidae) were isolated from 5.3, 4.9, and 0.4% of termite alates, respectively, and Bunonema and Halicephalobus were concomitant in 1.6% of alates. Additional C. formosanus alates were field-collected to establish laboratory colonies in sterilized rearing containers (SRC) to determine if alate-associated nematodes would colonize the newly established nest and/or brood. Among 1-yr-old termite colonies reared in SRCs, 26.9% of the colonies were positive for nematodes confirming that within-colony transmission of nematodes occurred. All three isolated nematode genera are free-living bacterivores capable of asexual reproduction. This suggests that these common co-occurring, termite-associated nematodes are opportunistic and facultative symbionts that receive increased opportunities of geographical dispersion through phoresy during termite dispersal flight events.

Nematodes from galls on Myrtaceae. XI. Descriptions of five new species of Fergusobia from Australia.

Five new species of Fergusobia are described. Fergusobia janetae Davies n. sp. is characterized by the combination of an arcuate to straight, spindle-shaped parthenogenetic female with a relatively small oesophageal gland, an extensile uterus and a conoid tail, an arcuate infective female with a bluntly rounded tail tip, and a C-shaped male with an arcuate to angular spicule and bursa arising at more than 90% of body length. Fergusobia robustae Davies n. sp. is characterized by the combination of a small, C-shaped parthenogenetic female with a short cylindroid tail with a broadly rounded tip; an arcuate to C-shaped, relatively broad, infective female with a tail tip that is almost hemispherical; and an arcuate male with a strong angular spicule and a bursa arising at 30-40% of body length. Fergusobia pruinosae Davies n. sp. is characterized by the combination of a medium sized, open C-shaped, parthenogenetic female in which the cuticle does not swell upon fixation, with a strongly sclerotised stylet, with a more or less narrowly conoid tail with a bluntly or broadly rounded tip; infective female that is arcuate to J-shaped with a notched tail tip; and open C-shaped males with stout, angular spicules and bursa arising near the secretory/excretory pore. Fergusobia pauciflorae Davies n. sp. is characterized by the combination of a medium sized, arcuate, parthenogenetic female with a small stylet, and a conoid tail with a bluntly rounded tip; a small, open C to J-shaped infective female with a broadly rounded to almost hemispherical tail tip; and straight to arcuate males with stout, angular spicules and bursa at ~70% of body length anterior to the cloaca. Fergusobia obliquae Davies n. sp. has a relatively broad, arcuate, parthenogenetic female having a small but strongly sclerotised stylet, and a short conoid tail with a bluntly rounded tip; an arcuate, infective female with an almost hemispherical tail tip; and C-shaped males with arcuate to angular (not heavily sclerotised) spicules and bursa arising 50-80% of body length anterior to tail. Sequencing of the 18S and 28S rDNA domains for F. janetae n. sp. and of mitochondrial DNA cytochrome oxidase subunit I (mtCOI) for F. pauciflorae n. sp. confirm that they are distinct species.

Large-scale diversification without genetic isolation in nematode symbionts of figs.

Diversification is commonly understood to be the divergence of phenotypes accompanying that of lineages. In contrast, alternative phenotypes arising from a single genotype are almost exclusively limited to dimorphism in nature. We report a remarkable case of macroevolutionary-scale diversification without genetic divergence. Upon colonizing the island-like microecosystem of individual figs, symbiotic nematodes of the genus Pristionchus accumulated a polyphenism with up to five discrete adult morphotypes per species. By integrating laboratory and field experiments with extensive genotyping of individuals, including the analysis of 49 genomes from a single species, we show that rapid filling of potential ecological niches is possible without diversifying selection on genotypes. This uncoupling of morphological diversification and speciation in fig-associated nematodes has resulted from a remarkable expansion of discontinuous developmental plasticity.

Effects of Infection by Belonolaimus longicaudatus on Rooting Dynamics among St. Augustinegrass and Bermudagrass Genotypes.

Understanding rooting dynamics using the minirhizotron technique is useful for cultivar selection and to quantify nematode damage to roots. A 2-yr microplot study including five bermudagrass ('Tifway', Belonolaimus longicaudatus susceptible; two commercial cultivars [TifSport and Celebration] and two genotypes ['BA132' and 'PI 291590'], which have been reported to be tolerant to B. longicaudatus) and two St. Augustinegrass ('FX 313', susceptible, and 'Floratam' that was reported as tolerant to B. longicaudatus) genotypes in a 5 x 2 and 2 x 2 factorial design with four replications, respectively, was initiated in 2012. Two treatments included were uninoculated and B. longicaudatus inoculated. In situ root images were captured each month using a minirhizotron camera system from April to September of 2013 and 2014. Mixed models analysis and comparison of least squares means indicated significant differences in root parameters studied across the genotypes and soil depths of both grass species. 'Celebration', 'TifSport' and 'PI 291590' bermudagrass, and 'Floratam' St. Augustinegrass had significantly different root parameters compared to the corresponding susceptible genotypes (P ≤ 0.05). Only 'TifSport' had no significant root loss when infested with B. longicaudatus compared to non-infested. 'Celebration' and 'PI 291590' had significant root loss but retained significantly greater root densities than 'Tifway' in B. longicaudatus-infested conditions (P ≤ 0.05). Root lengths were greater at the 0 to 5 cm depth followed by 5 to 10 and 10 to 15 cm of vertical soil depth for both grass species (P ≤ 0.05). 'Celebration', 'TifSport', and 'PI 291590' had better root vigor against B. longicaudatus compared to Tifway.

Nematodes from galls on Myrtaceae. IX. Fergusobia rosettae n. sp. on Melaleuca quinquenervia and F. tolgaensis n. sp. on Syzygium luehmannii, from Queensland.

Two new species of Fergusobia, collected from 'rosette' shoot bud galls on Melaleuca quinquenervia, and from leaf, stem, leaf and flower bud galls on Syzygium luehmannii, both from the Cairns region of Queensland, Australia, are described. Fergusobia rosettae Davies n. sp. is characterised by the combination of a small, arcuate parthenogenetic female having a short conoid tail with a bluntly rounded tip, an arcuate, relatively slender, infective female with an almost hemispherical tail tip, and arcuate males with arcuate to angular (not heavily sclerotised) spicules and leptoderan bursa arising at 40-50% of body length from tail tip. Fergusobia tolgaensis Davies n. sp. is characterised by the combination of a small open C-shaped parthenogenetic female with a broadly conoid tail, an arcuate infective female with a broadly rounded tail tip, and arcuate males with angular (not heavily sclerotised) spicules and short to mid-length leptoderan bursa. These two species of nematodes are associated with fly larvae that have dorsal shields comprising bars of raised cuticular ridges and spicules, similar to that of fly larvae from the M. leucadendra species group. The shield morphologies of these fly larvae and their possible genetic relationships are discussed. Possible evolutionary relationships of the Fergusobia nematodes from these galls are discussed, considering their morphology, DNA sequences, and the relationships of the associated Fergusonina flies and host plants.

Nematodes from galls on Myrtaceae. X. Fergusobia from galls on narrow-leaved Melaleuca spp. in Australia, with descriptions of three new species .

Three new species of Fergusobia, respectively collected from shoot bud galls on narrow-leaved Melaleuca spp. in Australia, are described. Fergusobia armillarisae n. sp. Davies is characterised by the combination of an arcuate to open C-shaped parthenogenetic female with an extensile uterus and a short, conoid tail, an arcuate infective female with a broadly rounded tail tip, and an arcuate male with an angular spicule and bursa arising at 50-80% of body length. Fergusobia decorae n. sp. Davies has an arcuate parthenogenetic female with a non-extensile uterus and a broadly conoid tail, an arcuate infective female with most curvature behind the vulva and a short tail with a broadly rounded tip, and an arcuate male with an arcuate spicule and bursa arising at 40-50% of body length. Fergusobia linariifoliae n. sp. Davies is characterised by the combination of an arcuate parthenogenetic female with an extensile uterus and a short, conoid tail with a bluntly rounded tip, a barely arcuate infective female with a broadly rounded tail tip, and an arcuate male with an angular spicule and bursa arising at 40-50% of body length. Earlier molecular analyses inferred from DNA sequencing of 28S rDNA D2/D3 domains and a portion of mitochondrial DNA cytochrome oxidase subunit I (mtCOI) are further discussed. 

Revision of the paraphyletic genus Koerneria Meyl, 1960 and resurrection of two other genera of Diplogastridae (Nematoda).

Recent inferences of phylogeny from molecular characters, as well as a reexamination of morphological and biological characters, reject the monophyly of the nematode genus Koerneria Meyl, 1960 (Diplogastridae). Here, Koerneria sensu lato is revised. The genus, which previously consisted of 40 species, is separated into three genera. Almost all of the transferred species are moved to the resurrected genus Allodiplogaster Paramonov & Sobolev in Skrjabin et al. (1954). Koerneria and Allodiplogaster are distinguished from each other by a weakly vs. clearly striated body surface, an undivided vs. divided stomatal cheilostom, and arrangement of the terminal ventral triplet of male genital papillae, namely in that v5 and v6 are paired and separated from v7 vs. v5-v7 being close to each other. Allodiplogaster is further divided into two groups of species, herein called the henrichae and striata groups, based on both morphological and life-history traits. The henrichae group is characterized by papilliform labial sensilla and male genital papillae, a conical tail in both males and females, and an association with terrestrial habitats and insects, whereas the striata group is characterized by setiform labial sensilla and male genital papillae, an elongated conical tail in both sexes, and an association with aquatic habitats. A second genus, Anchidiplogaster Paramonov, 1952, is resurrected to include a single species that is characterized by its miniscule stoma and teeth, unreflexed testis, and a distinct lack of male genital papillae or stomatal apodemes. Lastly, one further species that was previously included in Koerneria sensu lato is transferred to the genus Pristionchus Kreis, 1932. The revision of Koerneria sensu lato is necessitated by the great variability in its subordinate taxa, which occupy a variety of habitats, in addition to the increased attention to Diplogastridae as a model system for comparative mechanistic biology.

Nematodes from galls on Myrtaceae. VIII. Fergusobia from small galls on shoot buds, with descriptions of four new species.

Small shoot bud galls induced by the Fergusobia (Nematoda: Neotylenchidae)/Fergusonina (Diptera: Fergusoninidae) mutualism occur on various Eucalyptus spp. Four new species of Fergusobia, collected from small shoot bud galls on Eucalyptus camaldulensis, E. gomphocephala and E. leucoxylon, are described. Fergusobia gomphocephalae Davies n. sp. is morphologically characterized by a combination of a small C-shaped parthenogenetic female with a variable, conoid tail, a small C-shaped infective female with a hemispherical tail tip, and an arcuate or J-shaped male with a broad tail, angular spicule and short peloderan bursa. Fergusobia leucoxylonae Davies n. sp. has a C-shaped parthenogenetic female with a conoid tail with a narrowly rounded tip, an arcuate infective female with a broadly rounded tail tip, and an almost straight to barely J-shaped male with angular (not heavily sclerotised) spicule and short bursa. Fergusobia schmidti Davies & Bartholomaeus n. sp. has an arcuate to open C-shaped parthenogenetic female with a relatively large body diameter, relatively long stylet and small tail with a broadly rounded tail tip, an open C-shaped infective female with a broadly rounded to hemispherical tail tip, and an arcuate to barely J-shaped male with spicules angular at about 33% of their length and peloderan bursa arising at about half body length. Fergusobia sporangae Davies n. sp. has an arcuate to open C-shaped parthenogenetic female with a relatively long stylet and a broadly rounded tail tip, an arcuate infective female with a short tail with a broadly rounded to hemispherical tip, and an arcuate to barely J-shaped male with angular (not heavily sclerotised) spicule and short peloderan bursa. Various forms of small shoot bud galls are described. From phylogenetic analyses based on sequences of the D2/D3 expansion segment of the large subunit rRNA gene, the four new species belong to two sister clades of Fergusobia. The larval shield morphology of their associated fly species and possible genetic relationships are discussed. 

Nematodes from galls on Myrtaceae. VI. Fergusobia from galls on Angophora in Australia, with description of F. colbrani n. sp. and key.

Collection data and biological information is presented on the Fergusobia (Nematoda: Neotylenchidae)/ Fergusonina (Diptera: Fergusoninidae) mutualism inducing galls on Angophora in Australia. Three species and two morphospecies have been recognised. Fergusobia colbrani Davies n. sp. is described from soft spheroid leaf galls on Angophora floribunda. It is characterised by a combination of morphological characters including a small C-shaped parthenogenetic female with a short broadly conoid tail, an arcuate infective female with an almost hemispherical tail tip, and an arcuate to barely J-shaped male with an angular spicule having a notched tip and mid-length leptoderan bursa. A key to the species and morphospecies of nematodes collected from Angophora is presented. Possible relationships of these organisms are discussed based on evidence from the nematode morphology, gall forms, and the morphology of the dorsal shield of the associated Fergusonina fly larvae. 

Nematodes from galls on Myrtaceae. VII. Fergusobia from 'leafy' leaf bud galls in Australia, with re-description of Fergusobia tumifaciens (Currie 1937) Wachek 1955 and descriptions of Fergusobia planchonianae n. sp. and Fergusobia viminalisae n. sp.

Fergusobia tumifaciens (Currie 1937) Wachek 1955, the type species for the genus Fergusobia, is re-described from specimens collected from 'leafy' leaf bud galls on Eucalyptus bridgesiana near Albury in New South Wales, Australia. It is morphologically characterized by the combination of an open C-shaped parthenogenetic female with a small broadly conoid tail, a C-shaped infective female with a bluntly rounded tail tip, and an arcuate to J-shaped male with angular spicules, not heavily sclerotised, and short to mid-length peloderan bursa. Two new species of Fergusobia, collected from 'leafy' leaf bud galls on, respectively, Eucalyptus planchoniana in Queensland, and E. viminalis in South Australia, Australia, are described. Fergusobia planchonianae Davies n. sp. is characterised by the combination of a C-shaped parthenogenetic female with a conoid tail, an arcuate infective female with an hemispherical tail tip, and an almost straight to arcuate to C-shaped male with an angular spicule, a long peloderan bursa and a narrow tail. Fergusobia viminalisae Davies n. sp. is characterised by the combination of an open C-shaped parthenogenetic female with a broadly conoid tail, a C-shaped infective female with a bluntly rounded tail tip, and an arcuate to J-shaped male with an angular (not heavily sclerotised) spicule and short to mid-length peloderan bursa. The shield morphologies of the fly larvae associated with the 'leafy' leaf bud galls and their possible relationships are outlined. Possible evolutionary relationships of the Fergusobia nematodes from these galls are discussed, considering their morphology, DNA sequences, and the relationships of the associated Fergusonina flies and host plants. 

New plant-parasitic nematode from the mostly mycophagous genus Bursaphelenchus discovered inside figs in Japan.

A new nematode species, Bursaphelenchus sycophilus n. sp. is described. The species was found in syconia of a fig species, Ficus variegata during a field survey of fig-associated nematodes in Japan. Because it has a well-developed stylet and pharyngeal glands, the species is considered an obligate plant parasite, and is easily distinguished from all other fungal-feeding species in the genus based upon these characters. Although B. sycophilus n. sp. shares an important typological character, male spicule possessing a strongly recurved condylus, with the "B. eremus group" and the "B. leoni group" of the genus, it was inferred to be monophyletic with the "B. fungivorus group". The uniquely shaped stylet and well-developed pharyngeal glands is reminiscent of the fig-floret parasitic but paraphyletic assemblage of "Schistonchus". Thus, these morphological characters appear to be an extreme example of convergent evolution in the nematode family, Aphelenchoididae, inside figs. Other characters shared by the new species and its close relatives, i.e., lack of ventral P1 male genital papilla, female vulval flap, and papilla-shaped P4 genital papillae in males, corroborate the molecular phylogenetic inference. The unique biological character of obligate plant parasitism and highly derived appearance of the ingestive organs of Bursaphelenchus sycophilus n. sp. expands our knowledge of the potential morphological, physiological and developmental plasticity of the genus Bursaphelenchus.

Phylogenetic Status and Morphological Characters of Rhabditolaimus anoplophorae (Rhabditida: Diplogastridae).

Rhabditolaimus anoplophorae Kanzaki and Futai was re-isolated from its type host (carrier), the cerambycid beetle Anoplophora malasiaca, collected in an experimental field of the Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, Japan. The nematode was cultured on nematode growth medium plates seeded with Escherichia coli OP50, and its morphological characters and molecular profile were examined to modernize the description. Scanning electron microscopic and light microscopy revealed the presence of four stomatal flaps, a very long gymnostom, a single ventral papilla in males, and a horizontal slit-like vulval opening in females. The positions of the deirids, hemizonids, phasmids, and rectal glands are additionally described, and the absence of a male bursa was confirmed. Phylogenetically, the genus forms a well-supported clade in the family Diplogastridae. Rhabditolaimus anoplophorae is a member of the monophyletic Rhabditolaimus clade and is closely related to R. leuckarti and several undescribed species.