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The present study reports the occurrence of the genus Belonolaimus in the state of Sinaloa, Mexico, associated with native plants (i.e., Ziziphus amole and Stenocereus alamosensis ) in a natural coastal ecosystem. Both morphological and molecular approaches were employed to characterize the Sinaloa population. Notwithstanding of some morphological and morphometric variation between Belonolaimus from Sinaloa and other valid species, the characterization indicates that this population might belong to the Belonolaimus longicaudatus species complex. Molecular analyses based on the 28S gene and ITS1-5.8S-ITS2 regions of the ribosomal RNA (rRNA) identified four major clades within Belonolaimus ; however, none of the species including B. longicaudatus , B. gracilis , and B. euthychilus were supported as monophyletic; yet monophyly is argued to be a basic requirement of species status. Sequence divergence among different Belonolaimus populations and species varied according to the rRNA dataset (i.e., ITS1-5.8S-ITS2 > 28S > 18S) used, thus showing the importance of using genes with different rates of evolution to estimate species relationships. The fact that Belonolaimus has not been found in other cultivated (including on suitable hosts) areas in Sinaloa and that this population is relatively distant from the common B. longicaudatus groups (i.e., clades A and B) suggests that its appearance was not due to a recent introduction associated with the local agriculture.

The deep sea is Earth's largest habitat but little is known about the nature of deep-sea parasitism. In contrast to a few characterized cases of bacterial and protistan parasites, the existence and biological significance of deep-sea parasitic fungi is yet to be understood. Here we report the discovery of a fungus-related parasitic microsporidium, Nematocenator marisprofundi n. gen. n. sp. that infects benthic nematodes at methane seeps on the Pacific Ocean floor. This infection is species-specific and has been temporally and spatially stable over 2 years of sampling, indicating an ecologically consistent host-parasite interaction. A high distribution of spores in the reproductive tracts of infected males and females and their absence from host nematodes' intestines suggests a sexual transmission strategy in contrast to the fecal-oral transmission of most microsporidia. N. marisprofundi targets the host's body wall muscles causing cell lysis, and in severe infection even muscle filament degradation. Phylogenetic analyses placed N. marisprofundi in a novel and basal clade not closely related to any described microsporidia clade, suggesting either that microsporidia-nematode parasitism occurred early in microsporidia evolution or that host specialization occurred late in an ancient deep-sea microsporidian lineage. Our findings reveal that methane seeps support complex ecosystems involving interkingdom interactions between bacteria, nematodes, and parasitic fungi and that microsporidia parasitism exists also in the deep-sea biosphere.

In this study, 10% of all registered fishermen in the coastal towns of Navachiste in Sinaloa, in northwestern Mexico, answered a survey designed to collect data on their perceptions of the following topics: the impact of turtle meat consumption; human health; bycatch; illegal turtle fishing; the illegal sea turtle market; the local economy; pollution; environmental education; the success of protective legislation; and sea turtle-based ecotourism. Perceptions were analyzed using the fuzzy logic method through classification into 5 fuzzy membership sets: VL, very low; L, low; M, moderate; H, high; VH, very high. The 9 topics generated decision areas upon applying fuzzy inference that revealed the membership level of the answers in each fuzzy set. The economic potential of sea turtle-based ecotourism and the economic profitability of the illegal turtle meat market were perceived as VL. Conservation legislation was perceived as H, although inefficiently applied due to corruption. Ecotourism and impacts on sea turtles were perceived as VL, because they were deemed unprofitable activities at the individual and community levels. Environmental education was perceived as L, because it centers on nesting, hatching and releasing turtles and is directed at elementary and middle-school students. While fishers perceive a serious negative impact of fishing activities on sea turtles in the San Ignacio-Navachiste-Macapule area, they do not see themselves individually as part of the problem. Achieving sea turtle conservation in this region requires: suitable ecotourism infrastructure, government investments in promotion, and studies to estimate the minimum number of tourists needed to assure profitability., (© 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.)

Two new species, Neotobrilus nicsmolae n. sp. and Chronogaster carolinensis n. sp. are described from a small, acidic, temperate, natural lake in North Carolina. N. nicsmolae n. sp. comes close to three members of the genus reported from North America, N. filipjevi, N. longus, and N. hopei. However, N. nicsmolae is unique with in the genus in having a combination of characters: size smaller than 1,700 μm, shorter outer labial and cephalic setae, tail shorter than 250 μm, last ventromedian supplement close (about 5 μm) to cloacal opening, spicule length of 61 to 85 μm, flagelloid sperm, and possession of subterminal setae. Assessment of relationships among clades within the Triplonchida using DNA sequences of the D2D3 expansion segment of the LSU rDNA showed that the family Trichodoridae and the genus Tripyla were recovered as monophyletic. The genus Tobrilus was recovered as monophyletic in the neighbor-joining and maximum likelihood trees, but that was not so in the maximum-parsimony tree. The separation among genera of the Trichodoridae, i.e., Trichodorus and Paratrichodorus, was not clear-cut in all phylograms. Chronogaster carolinensis n. sp. in having one ventral mucro with no spine and vacuolated lateral glandular bodies comes close to C. typica and C. ethiopica but differs from all hitherto known species in a combination of characteristics: in having long cephalic setae, long stoma, crystalloid bodies, vacuolated lateral glandular bodies, and a tail terminus with blunt ventral mucro, and its lack of lateral line.

We used morphological and molecular approaches to evaluate the diversity of free-living marine nematodes (order Enoplida) at four coastal sites in the Gulf of California and three on the Pacific coast of Baja California, Mexico. We identified 22 morphological species belonging to six families, of which Thoracostomopsidae and Oncholaimidae were the most diverse. The genus Mesacanthion (Thoracostomopsidae) was the most widespread and diverse. Five allopatric species, genetically and morphologically differentiated, were found in two localities in the Gulf of California ( M . sp1 and M . sp2) and three in the Pacific coast ( M . sp3, M . sp4 and M . sp5). Overall, we produced 19 and 20 sequences for the 18S and 28S genes, respectively. Neither gene displayed intraspecific polymorphisms, which allowed us to establish that some morphological variation was likely either ontogenetic or due to phenotypic plasticity. Although 18S and 28S phylogenies were topologically congruent (incongruence length difference test, P  > 0.05), divergences between species were much higher in the 28S gene. Moreover, this gene possessed a stronger phylogenetic signal to resolve relationships involving Rhabdodemania and Bathylaimus . On the other hand, the close relationship of Pareurystomina (Enchilidiidae) with oncholaimids warrants further study. The 28S sequences (D2D3 domain) may be better suited for DNA barcoding of marine nematodes than those from the 18S rDNA, particularly for differentiating closely related or cryptic species. Finally, our results underline the relevance of adopting an integrative approach encompassing morphological and molecular analyses to improve the assessment of marine nematode diversity and advance their taxonomy.

The role of habitat complexity has been widely neglected in the study of meiofaunal community patterns. We studied the intertidal nematode community of a structurally complex macrotidal beach exhibiting contrasting microhabitats (sandbars and runnels) to understand the influence of environmental gradients and habitat heterogeneity in the community structure. We tested whether topographical complexity affected (1) the zonation pattern in terms of abundance and diversity, and (2) local diversity by promoting compartmentalization into distinct faunal groups. Our analyses revealed three major faunal assemblages along the exposure gradient associated to differences in mean grain size and chlorophyll a . Diversity patterns involved a mid-intertidal peak, consistent with the intermediate disturbance hypothesis, and another peak at the limit with the subtidal region, consistent with the transition zone. These results highlight the predominance of environmental gradients in establishing intertidal zonation. However, microhabitats differed in environmental conditions and possessed significantly distinct nematofaunal communities. Runnels featured higher levels of taxonomic and functional diversity, many unique genera, and the community differed from the assemblage at the limit to the subtidal, stressing their role as distinct microhabitats. The nematofauna of the structurally complex beach was more diverse than the one from a homogeneous beach nearby, supporting the hypothesis that structural heterogeneity promotes diversity by compartmentalization and highlighting the importance of microhabitats in the assessment of biodiversity. Contrary to previous predictions, our results indicate potentially high regional marine nematode diversity in the Upper Gulf of California.

The root lesion nematodes of the genus Pratylenchus Filipjev, 1936 are migratory endoparasites of plant roots, considered among the most widespread and important nematode parasites in a variety of crops. We obtained gene sequences from the D2 and D3 expansion segments of 28S rRNA partial and 18S rRNA from 31 populations belonging to 11 valid and two unidentified species of root lesion nematodes and five outgroup taxa. These datasets were analyzed using maximum parsimony and Bayesian inference. The alignments were generated using the secondary structure models for these molecules and analyzed with Bayesian inference under the standard models and the complex model, considering helices under the doublet model and loops and bulges under the general time reversible model. The phylogenetic informativeness of morphological characters is tested by reconstruction of their histories on rRNA based trees using parallel parsimony and Bayesian approaches. Phylogenetic and sequence analyses of the 28S D2-D3 dataset with 145 accessions for 28 species and 18S dataset with 68 accessions for 15 species confirmed among large numbers of geographical diverse isolates that most classical morphospecies are monophyletic. Phylogenetic analyses revealed at least six distinct major clades of examined Pratylenchus species and these clades are generally congruent with those defined by characters derived from lip patterns, numbers of lip annules, and spermatheca shape. Morphological results suggest the need for sophisticated character discovery and analysis for morphology based phylogenetics in nematodes.

Nematodes of the suborder Cephalobina include an ecologically and morphologically diverse array of species that range from soil-dwelling microbivores to parasites of vertebrates and invertebrates. Despite a long history of study, certain of these microbivores (Cephaloboidea) present some of the most intractable problems in nematode systematics; the lack of an evolutionary framework for these taxa has prevented the identification of natural groups and inhibited understanding of soil biodiversity and nematode ecology. Phylogenetic analyses of ribosomal (LSU) sequence data from 53 taxa revealed strong support for monophyly of taxa representing the Cephaloboidea, but do not support the monophyly of most genera within this superfamily. Historically these genera have primarily been recognized based on variation in labial morphology, but molecular phylogenies show the same general labial (probolae) morphotype often results from recurrent similarity, a result consistent with the phenotypic plasticity of probolae previously observed for some species in ecological time. Phylogenetic analyses of LSU rDNA also recovered strong support for some other groups of cephalobs, including taxa representing most (but not all) Panagrolaimoidea. In addition to revealing homoplasy of probolae, molecular trees also imply other unexpected patterns of character evolution or polarity, including recurrent similarity of offset spermatheca presence, and representation of complex probolae as the ancestral condition within Cephaloboidea. For Cephalobidae, molecular trees do not support traditional genera as natural groups, but it remains untested if deconstructing probolae morphotypes or other structural features into finer component characters may reveal homologies that help delimit evolutionary lineages.

Bursaphelenchus platzeri n. sp., an associate of nitidulid beetles in southern California, is described and illustrated. Adult males and females of B. platzeri n. sp. were examined by scanning electron microscopy for ultrastructural comparisons with other members of the genus. Bursaphelenchus cocophilus (red ring nematode) appears to be the closest related taxon to B. platzeri n. sp. based upon shared morphological features of the fused spicules, female tail shape, phoresy with non-scolytid beetles, and molecular analysis of the near full-length small subunit (SSU) rDNA. Unfortunately, sequence data from the D2D3 expansion segments of the large subunit (LSU) rDNA and partial mitochondrial DNA COI did not help resolve the relationship of nearest relative. In addition to significant molecular sequence differences in SSU, LSU, and COI, B. platzeri n. sp., which is an obligate fungal feeder, can be differentiated from B. cocophilus because it is an obligate parasite of palms. Bursaphelenchus platzeri n. sp. can be differentiated from all other species of Bursaphelenchus by the length and shape of the female tail and spicule morphology. The spicules are fused along the ventral midline and possess unfused cucullae; the fused unit appears to function as a conduit for sperm. Population growth of B. platzeri n. sp. was measured in a time-course experiment at 25 degrees C in the laboratory on cultures of the fungus Monilinia fructicola grown on 5% glycerol-supplemented potato dextrose agar (GPDA). Nematode population densities rapidly increased from 25 to approximately 200,000/culture within 14 d and then plateaued for up to 28 d.

Molecular surveys of meiofaunal diversity face some interesting methodological challenges when it comes to interstitial nematodes from soils and sediments. Morphology-based surveys are greatly limited in processing speed, while barcoding approaches for nematodes are hampered by difficulties of matching sequence data with traditional taxonomy. Intermediate technology is needed to bridge the gap between both approaches. An example of such technology is video capture and editing microscopy, which consists of the recording of taxonomically informative multifocal series of microscopy images as digital video clips. The integration of multifocal imaging with sequence analysis of the D2D3 region of large subunit (LSU) rDNA is illustrated here in the context of a combined morphological and barcode sequencing survey of marine nematodes from Baja California and California. The resulting video clips and sequence data are made available online in the database NemATOL (http://nematol.unh.edu/). Analyses of 37 barcoded nematodes suggest that these represent at least 32 species, none of which matches available D2D3 sequences in public databases. The recorded multifocal vouchers allowed us to identify most specimens to genus, and will be used to match specimens with subsequent species identifications and descriptions of preserved specimens. Like molecular barcodes, multifocal voucher archives are part of a wider effort at structuring and changing the process of biodiversity discovery. We argue that data-rich surveys and phylogenetic tools for analysis of barcode sequences are an essential component of the exploration of phyla with a high fraction of undiscovered species. Our methods are also directly applicable to other meiofauna such as for example gastrotrichs and tardigrades.

In a study of relationships among selected cyst-forming and noncyst-forming species of Heteroderoidea, combined sequences comprised of DNA from part of the conserved 18S ribosomal RNA gene (rDNA) plus the complete ITS rDNA segment were more similar to analyses based on the ITS data alone than to analyses based on the 18S data alone. One of the two noncyst-forming species, Ekphymatodera thomasoni, grouped with cyst-forming species of Heteroderoidea. Bilobodera flexa, also a noncyst-forming species, was separated from all the other taxa by a long branch. Afenestrata koreana, with a weakly sclerotized cyst, grouped closely with H. bifenestra. These observations suggest that phylogenetic analyses using molecular data may aid in our understanding of the evolution of cyst formation in nematodes, including the possibility of secondary loss. The usefulness of molecular phylogenetic analyses in nematodes may depend more on the particular selection of taxa than on mere addition of data from additional genes.

Phylogenetic relationships among six isolates of Halicephalobus gingivalis (Stefanski, 1954), a species with pathogenic potential in horses and humans, were evaluated using DNA sequences from the nuclear large-subunit ribosomal RNA (LSU rDNA) gene. Sequences from nematodes obtained from in vitro cultures (soil or clinical sources), or isolated from infected horse tissues, were compared. Gene sequences from a fatal equine clinical case from southern California and a free-living isolate recovered from southern California soil showed no fixed differences. Sequences from isolates representing two fatal equine cases from North America, one from Ontario, Canada and another from Tennessee also showed no fixed differences. In contrast, two equine cases from Tennessee had 18 fixed differences for this LSU region, the greatest observed among isolates from horses. Phylogenetic analysis of six Halicephalobus sequences and four outgroup taxa by maximum parsimony yielded one tree with five well-supported clades. This phylogeny did not group isolates of Halicephalobus strictly by region of geographic isolation or source of sample, and depicted one clinical and one soil isolate as sister taxa. These results confirm that free-living environmental isolates are potential sources of infection for horses. The phylogeny also reveals that diverse isolates can cause infections in horses within a relatively limited geographic region, and conversely that genetically similar sister taxa can be recovered from geographically distant localities. PCR primers that selectively amplify Halicephalobus DNA were designed and tested based on comparison of closely related nematodes as inferred from phylogenetic analysis.

Evolutionary relationships based on ribosomal DNA (rDNA) sequence data for a previously unknown species of Globodera from Portugal, Punctodera chalcoensis from Mexico, and P. punctata from Estonia, plus previously published sequences, support the following relationships: (((Cactodera weissi, G. artemisiae, C. milleri), ((G. sp. Bouro, G. sp. Canha, G. sp. Ladoeiro), ((G. pallida, G. rostochiensis), (P. chalcoensis, P. punctata)))), Heterodera avenae). Globodera sp. from Portugal, which can be confused with potato cyst nematodes by phytosanitary services when the identification is based only on morphological characters, is clearly different based on our molecular data. In addition, the rDNA data show the Globodera sp. to be only distantly related to other European Globodera species that parasitize Asteraceae. Punctodera chalcoensis and P. punctata form a sister clade to the G. pallida + G. rostochiensis clade.

Three new species of Nothacrobeles are described from localities in the Mojave Desert, southern California. Nothacrobeles triniglarus n. sp. is characterized by the presence of a long post-vulval sac and three tubular adoral projections. Both N. spatulatus n. sp. and N. nanocorpus n. sp. are smaller than any other known species within the genus. Nothacrobeles spatulatus n. sp. has labial probolae that are short and spatulate without a basal ridge, whereas those of N. nanocorpus n. sp. are flattened and plate-like. Furthermore, N. nanocorpus n. sp. is unique by its extremely short esophageal corpus (less than 25 microm long in adult females) and the small size of its guard processes. An emended diagnosis of the genus is given to accommodate distinctive characteristics of these new species. A table comparing the 11 valid species of Nothacrobeles is presented.

Cactodera salina n. sp. (Heteroderinae) is described from roots of the estuary plant Salicornia bigelovii (Chenopodiaceae), in Puerto Pefiasco, Sonora, Mexico, at the northern tip of the Sea of Cortez. The halophyte host is grown experimentally for oilseed in plots flooded daily with seawater. Infected plants appear to be adversely affected by C. salina relative to plants in noninfested plots. Cactodera salina extends the morphological limits of the genus. Females and cysts have a very small or absent terminal cone and deep cuticular folds in a zigzag pattern more typical of Heterodera and Globodera than of Cactodera spp. Many Cactodera spp. have a tuberculate egg surface, whereas C. salina shares the character of a smooth egg with C. amaranthi, C. weissi, and C. acnidae. Only C. milleri and C. acnidae have larger cysts than C. salina. Face patterns of males and second-stage juveniles, as viewed with scanning electron microscopy, reveal the full complement of six lip sectors as in other Cactodera spp. Circumfenestrae of C. salina are typical for the genus.

Meloidogyne sp. from five pecan (Carya illinoensis) orchards in Texas were distinctive in host range and iszoyme profiles from common species of Meloidogyne but were morphologically congruent with Meloidogyne partityla Kleynhans, a species previously known only in South Africa. In addition to pecan, species of walnut (Juglans hindsii and J. regia) and hickory (C. ovata) also were hosts. No reproduction was observed on 15 other plant species from nine families, including several common hosts of other Meloidogyne spp. Three esterase phenotypes and two malate dehydrogenase phenotypes of M. partityla were identified by polyacrylamide gel electrophoresis. Each of these isozyme phenotypes was distinct from those of the more common species M. arenaria, M. hapla, M. incognita, and M. javanica.

A stunt nematode, Tylenchorhynchus thermophilus n. sp., is described and illustrated from soil collected around roots of saltgrass (Distichlis spicata) in Death Valley, California. It is distinguished from the similar species, T. ewingi, T. mexicanus, and T. mashoodi, in having a longer female body, longer tail with more annules, and larger phasmids. Physical and chemical analysis of soil from saltgrass roots showed it to consist of 71% sand and possess high salinity (salt content of 0.51%) and a pH of 9.3.

The highly irregular distribution of nuclear material in the host nurse cell induced by Meloidodera floridensis has made it difficult to interpret the number of nuclei from two-dimensional micrographs alone. The primary goal of this investigation was to determine the distribution of nuclear material from a three-dimensional solid surface model of the nurse cell nucleus. This model demonstrated the continuity of nuclear material as a single highly irregular nucleus. Custom computer graphics programs were written to accept digitized tracings of nuclear material. From these digitized tracings, a wireframe or polygonalized mesh model was generated. The model was shaded, colored, rotated, and analyzed. This technique provides controlled transparency of the model to display nucleoli within the nucleus. Photographs of the computer screen, color printouts, and video recordings were used to record final results. These refined computer graphic tools have a range of applications in nematode host-parasite relationships, ontogeny, and morphology.

Bursaphelenchus abruptus n. sp., an associate of the digger bee, Anthophora abrupta (Hymenoptera: Anthophoridae), is described and illustrated. Bursaphelenchus abruptus n. sp. can be differentiated from other species of Bursaphelenchus by the absence of head annules, stylet length, length of the postuterine sac, shape of female tail, spicule morphology, and male caudal papillae arrangement. Two plant-pathogenic fungi, Monilinia fructicola and Botrytis cinerea, and a Monilia sp. isolated from an adult bee from Prince Georges County, Maryland, were good hosts for B. abruptus n. sp. Dauer juveniles (JIII) of B. abruptus n. sp. were isolated from the reproductive tracts of A. abrupta from Montgomery County, Alabama, for measurements and comparison with J2 -JIII inter-molts from a 4-week-old monoxenic culture on Monilia sp. Gonad lengths in dauer juveniles isolated from A. abrupta were highly variable (49 +/- 23 mum SD; range 21-93 mum; n = 29) compared with J2-JIII intermolts from culture (28 +/- 7 mum SD; range = 16-42 mum; n = 16), suggesting that postembryonic gonad development may continue while dauers are in the bee host. Adult males and females of B. abruptus n. sp. were examined with scanning electron microscopy (SEM) for ultrastructural comparisons with other members of the genus Bursaphelenchus.

The population density of Helicotylenchus lobus and the percentage of the population with spores of Pasteuria penetrans were determined for 10 monthly intervals in naturally infested turf grass soil at Riverside, California. The percentage of nematodes with attached spores ranged from 40% to 67%. No relationship was found between nematode density and the percentage of nematodes with spores. The mean and maximum numbers of spores adhering per nematode with at least one spore ranged from 2 to 8 and 7 to 66, respectively. The mean number of spores per nematode (based on total number of H. lobus) was correlated with the percentage of nematodes with spores. Spores adhered to both adult and juvenile H. lobus. Between 9% and 32% of the nematodes with spores had been penetrated and infected by the bacterium. Many infected nematodes were dead, but mature spores were also observed within living adult and juvenile H. lobus that exhibited no apparent reduction in viability and motility. Spore and central endospore diameters of this P. penetrans isolate were larger than those reported for the type isolate from Meloidogyne incognita, but transmission and scanning electron microscopy did not reveal significant morphological differences between the two isolates. Spores of the isolate associated with H. lobus did not adhere to juveniles of M. incognita.

Host responses to Meloidodera floridensis Chitwood et al., 1956, M. charis Hooper, 1960, and M. belli Wouts, 1973 were examined on loblolly pine, peony, and sage, respectively, with light, scanning, and transmission electron microscopy. In each case the nematodes induce a single uninucleate giant cell. The giant cell is initiated in the pericycle and expands as it matures. The mature giant cell induced by M. floridensis is surrounded by vascular parenchyma, whereas that caused by M. charts and M. belli coutacts xylem and phloem. The cell wall of giant cells induced by all three Meloidodera spp. is generally thicker than that of surrounding cells, with the thickest part adjacent to the lip region of the nematode. The thinner portion of the wall includes numerous pit fields with plasmodesmata, but wall ingrowths were not detected in a thorough examination of the entire wall. The nucleus of a giant cell induced by M. goridensis is highly irregular in shape with deep invaginations, whereas those caused by M. charis and M. belli include a cluster of apparently interconnected nuclear units. Organelles, including mitochondria, endoplasmic reticulum, and plastids of giant cells caused by Meloidodera, are typical of those reported in host responses of other Heteroderidae. The formation of a single uninucleate giant cell by Meloidodera, Cryphodera, Hylonerna, and Sarisodera, but a syncytium by Atalodera and Heterodera sensu lato, might be considered in conjunction with additional characters to determine the most parsimonious pattern of phylogeny of Heteroderidae.

The histopathology of two populations of Sarisodera hydrophila Wouts and Sher, 1971 was examined on Salix lasiolepis Benth. (willow), Populus fremontii Wats. (cottonwood), and Lyonothamnus floribundus Gray (ironwood) using light microscopy as well as scanning and transmission electron microscopy. Sarisodera hydrophila induces formation of a single uninucleate hypertrophied cell (giant cell) which varies only slightly among the three hosts. The giant cell is enclosed by the root stele and contacts phloem, vascular cambium, and xylem. The single hypertrophied nucleus of the giant cell is ameboid or lobulate in shape, generally with a single nucleolus. The cell is characterized by a wall which is separated into two distinct regions about 2 mum and 13 mum thick; the thicker region occurs adjacent to the nematode head. Cell wall ingrowths, such as those associated with host responses to certain other plant-parasitic nematodes, were not observed in giant cells induced by S. hydrophila. However, a high frequency of pit fields with plasmodesmata occurred in the thinner portion of the cell wall which is adjacent to vascular elements. Roots of the three hosts simultaneously infected with S. hydrophila and Meloidogyne sp. resulted in adjacent responses characteristic of each nematode, supporting the view that the specific type of host response is a function of the nematode rather than the host. The varying expressions of host responses among Heteroderoidea may be useful in testing congruency with existing interpretations of phylogeny.

A new species of Cryphodera Colbran, 1966, parasitic on wild rose (Rosa sp. L.), is described from Utah, USA. Cryphodera utahensis n. sp. most closely resembles C. podocarpi (Wouts, 1973) Luc et al., 1978, but is distinct with respect to a number of characters including juveniles with a longer esophagus (206 versus 142 mum), shorter tail (47 versus 69 mun), and four rather than three incisures in the lateral field. Females of C. utahensis have a terminal protuberance which is more pronounced than in other species. Scanning electron microscope observations of the lip region of males indicate a labial disc surrounded by six lip sectors. However, the remainder of the lip region is comprised of irregularly-shaped plates; similar patterns with longitudinal striae apparently characterize males throughout the genus. The lip pattern of juveniles of C. utahensis n. sp. includes an oval labial disc surrounded by six lip sectors; transverse striae extend the height of the lip region without longitudinal striae. The type locality of C. utahensis confirms a broader distribution of the genus than was indicated for other species, which are limited to Australia (Queensland) and New Zealand.

Four new species and a new genus of Heteroderidae from California are described, and their significance for phylogenetic analysis of the family is discussed. The new genus with type species, Ekphymatodera thomasoni n. gen., n. sp., shares many characteristics with Hylonema Luc, Taylor, &Cadet, 1978, but it is distinguished by its much greater vulva-anus distance and unique cuticular pattern. Hypotheses of relationships of Ekphymatodera and Hylonema with Sarisodera Wouts and Sher, 1971 versus Heterodera Schmidt, 1871 are discussed. Verutus californicus n. sp. is larger than the type species, Verutus volvingentis Esser, 1981, differing in females particularly by the greater distance of its excretory pore from the anterior end. Monophyly of Verutus, which may be an outgroup of all other Heteroderidae, is strengthened by description of V. californicus. Atalodera trilineata n. sp. differs from other ataloderines by having second-stage juveniles with three lateral lines and from the type, Atalodera ucri Wouts and Sher, 1971, by the more subtle cuticular pattern of females and longer juveniles with much longer tails. Atalodera festucae n. sp., with four lateral lines in juveniles, has smaller females than A. trilineata and has a protruding dorsal vulval lip. A unique common ancestor for Atalodera-Sherodera-Thecavermiculatus is supported, and monophyly with Thecavermieulatus andinus Golden, Franco, Jatala, &Astocaza, 1973 is considered.

Atalodera ucri, Wouts and Sher, 1971, and A. lonicerae, (Wouts, 1973) Luc et al., 1978, induce similar multinucleate syncytia in roots of golden bush and honeysuckle, respectively. The syncytium is initiated in the cortex; as it expands, it includes several partially delimited syncytial units and distorts vascular tissue. Outer walls of the syncytium are relatively smooth and thickest near the feeding site of the nematode; inner walls are interrupted by perforations which enlarge as syncytial units increase in size. The cytoplasm of the syncytium is granular and includes numerous plastids, mitochondria, vacuoles, Golgi, and a complex network of membranes. Nuclei are greatly enlarged and amoeboid in shape. Although more than one nucleus sometimes occur in a given syncytial unit, no mitotic activity was observed. Syncytia induced by species of Atalodera chiefly differ from those of Heterodera sensu lato by the absence of cell wall ingrowths; wall ingrowths increase solute transport and characterize transfer cells. In syncytia of Atalodera spp., a high incidence of pits and pit fields in walls adjacent to vasctdar elements suggests that in this case plasmodesmata provide the pathway for increased entry of sohttes. The formation of a syncytium by species of Atalodera and Heterodera sensu lato, but a single uninucleate giant cell by Sarisodera and Hylonema, indicates a pattern of host responses that may be useful, with other characters, for phylogenetic inference for Heteroderidae.