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Sauertylenchus maximus was discovered during a survey conducted at the Arlington National Cemetery, Virginia, for the type specimens of Hoplolaimus galeatus. Besides the fresh material, the fixed specimens of S. maximus were also studied by molecular and morphological means. The morphological and morphometric characteristics of the recovered fresh material were consistent with the original and other description(s) of this species. The fixed specimens used in this study were preserved in a 3% formaldehyde and 2% glycerin solution for over 20 yr. Molecular analyses of the fresh and fixed specimens were performed using internal transcribed spacer, D2–D2 expansion segments of 28S large subunits, and 18S small subunit ribosomal DNA sequences. To our knowledge, this represents the first report of S. maximus from Virginia and the first report of a successful DNA extraction from fixed nematode specimens.

Specimens of a tylenchid nematode were recovered in 2019 from soil samples collected from a corn field, located in Pickens County, South Carolina, USA. A moderate number of Tylenchus sp. adults (females and males) were recovered. Extracted nematodes were examined morphologically and molecularly for species identification, which indicated that the specimens of the tylenchid adults were a new species, described herein as Tylenchus zeae n. sp. Morphological examination and the morphometric details of the specimens were very close to the original descriptions of Tylenchus sherianus and T. rex. However, females of the new species can be differentiated from these species by body shape and length, shape of excretory duct, distance between anterior end and esophageal intestinal valve, and a few other characteristics given in the diagnosis. Males of the new species can be differentiated from the two closely related species by tail, spicules, and gubernaculum length. Cryo-scanning electron microscopy confirmed head bearing five or six annules; four to six cephalic sensilla represented by small pits at the rounded corners of the labial plate; a small, round oral plate; and a large, pit-like amphidial opening confined to the labial plate and extending three to four annules beyond it. Phylogenetic analysis of 18S rRNA gene sequences placed Tylenchus zeae n. sp. in a clade with Tylenchus arcuatus and several Filenchus spp., and the mitochondrial cytochrome oxidase c subunit 1 (COI) gene region separated the new species from T. arcuatus and other tylenchid species. In the 28S tree, T. zeae n. sp. showed a high level of sequence divergence and was positioned outside of the main Tylenchus-Filenchus clade.

Barley root-knot nematode, Meloidogyne naasi Franklin, 1965, is one of the most important pest nematodes infecting monocots (Franklin, 1965). Two-inch core soil samples collected from a golf course in Ada County, Idaho were submitted for identification in November of 2019. A high number of Meloidogyne sp. juveniles were recovered from both soil samples using sieving and decantation followed by the sugar centrifugal flotation method. They were examined by light microscopy, morphometric measurements, and multiple molecular markers, including the ribosomal 28S D2–D3 and intergenic spacer 2 (IGS-2) regions, mitochondrial markers cytochrome oxidase I (COI) and the interval from COII to 16S, and the protein-coding gene Hsp90. Morphometrics as well as BlastN comparisons with other root-knot nematode sequences from GenBank were consistent with identification as M. naasi. Phylogenetic trees inferred from 28S, IGS-2, COI, or Hsp90 alignments each separated the Idaho population into a strongly supported clade with other populations of M. naasi, while the COII-16S interval could not resolve M. naasi from M. minor. This report represents the first morphological and molecular characterization of Meloidogyne naasi from turfgrass in Idaho.

Beech leaf disease (BLD), caused by the Litylenchus crenatae ssp. mccannii (Lcm) nematode, is an emerging threat to beech trees. This disease is characterized by distinct leaf symptoms, including leaf interveinal banding and thickened leaf texture, which leads to eventual tree mortality. Understanding Lcm dispersal mechanism(s) is crucial for managing BLD, yet these remain largely unknown, posing a major barrier to its effective management. This study represents a pioneering investigation into the abiotic and biotic vectors that potentially contribute to the local dispersal of Lcm in natural American beech (Fagus grandifolia) forest systems in the Northeastern United States. An experiment was set up in Stone Valley Forest, Pennsylvania (PA), using four funnel stands placed at variable distances from naturally BLD-infected beech trees. This approach enabled the recovery of active Lcm nematodes from each funnel, demonstrating their ability to naturally disperse at least 11.74 m from the nearest BLD-infected tree. The findings highlight the role of abiotic factors involved in the dispersal dynamics of Lcm, especially wind and humidity, as indicated by a generalized linear model. The current study also uncovered the incidental association of Lcm with other organisms beneath the canopy of BLD trees, including spiderwebs and caterpillars. To our knowledge, this is the first study to document the potential vectors involved in the local dispersal of Lcm, offering valuable information for the biology of this nematode, as well as insight into the development of effective BLD management strategies. The findings contribute to broader efforts in advancing the understanding of the local spread of BLD, highlighting the complex interplay of abiotic and biotic factors in this disease dispersal. [ABSTRACT FROM AUTHOR]

Summary: Rice ranks as the third most important staple cereal food crop in Kenya, following maize and wheat. The demand for rice has been increasing at a faster rate than most cereals, occasionally requiring imports to meet local needs. In response, the Kenyan government has been implementing a programme to increase rice production by expanding irrigated lowland rice schemes from 32 988 to 171 676 ha, while increasing rain-fed upland production areas four-fold to 42 000 ha by 2030. However, with continued rice monocropping in irrigated lowland fields and intensification in rain-fed upland ecosystems, there is a growing concern that plant-parasitic nematodes may emerge as a significant problem across rice ecosystems. This study characterised the nematode genera associated with rice in Kenya and assessed their diversity and distribution across rice ecosystems, with a focus on Hirschmanniella species. Eleven nematode genera were identified in both ecosystems, indicating a relatively high diversity. These genera, ranked by prominence, included Hirschmanniella , Hoplolaimus , Pratylenchus , Helicotylenchus , Meloidogyne , Ditylenchus , Trichodorus , Xiphinema , Rotylenchus , Longidorus and Paratylenchus. The family Tylenchidae was also found to be an important component of the nematofauna. Both morphological and molecular analyses confirmed the presence of Hirschmanniella oryzae in irrigated lowland and rain-fed upland rice, which represents the first documented report for Kenya. A notably large molecular variation was also observed for these Kenyan populations on the 18S region, with intraspecific variation up to 10 bp difference. Understanding the diversity, distribution, and species composition of nematodes in rice ecosystems is important for raising awareness among plant protection services, farmers, cooperatives and extension agents about plant-parasitic nematodes and their challenges in rice production. Future research should build on this knowledge to support extensive studies on population dynamics and damage threshold, focusing on local rice cultivars to develop effective management strategies, including breeding programmes and other cultural practices. [ABSTRACT FROM AUTHOR]

In April 2018, a cyst nematode was discovered from soil samples collected from a cactus garden collection in Meridian, Ada County, Idaho, USA. The cactus garden collection field reported was observed with localized areas of heavily stunted plants. Roots from affected plants displayed moderate numbers of nematode cysts. Living nematode juveniles (J2) recovered from the cysts were examined morphologically and molecularly for species identification which indicated that the specimens were Cactodera cacti. This is the first report of the cactus cyst nematode, C. cacti in Idaho.

In August of 2021, several cysts with juveniles and eggs were discovered during a vegetation survey conducted at the Arlington National Cemetery, Virginia. Eight soil samples were collected from the rhizosphere region of the common grass (Festuca arundinacea L.) and processed at the Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL). Cysts were light to dark brown in color, and oval to pear-shaped without bullae in young cysts but present in older cysts and with prominent vulval cone. The juveniles had slightly concave stylet knobs projecting sometimes anteriorly, tail tapering gradually to a narrowly rounded terminus, and hyaline tail terminus conspicuous at least twice the length of stylet. The molecular analysis included the analysis of three gene sequence fragments: D2–D3 of 28S rRNA, ITS rRNA, and COI. The nematode species was identified by both morphological and molecular means as Stone's cyst nematode, Punctodera stonei. Detection of P. stonei in Virginia represents a new record of this species in the United States, and a second report after Canada in North America.

Summary: A new needle nematode species, Longidorus patuxentensis n. sp., was collected along the banks of the Western Branch Patuxent River from Upper Marlboro, MD, USA, and described herein. Female body length of the new species ranges from 3.8 to 5.2 mm, with a set off lip region by depression, 77-92 μ m long odontostyle, 40-53 μ m long odontophore, vulva located at 46.3-50.1% and tail conoid with bluntly rounded tip. The new species has four juvenile developmental stages and no males. It looks morphologically similar to L. breviannulatus , L. elongatus , L. martini , L. americanus , L. grandis , L. sabalanicus and L. sturhani by having a ventrally curved to spiral body, generally similar lip region and conoid tail with a rounded terminus, but differs from these species by the odontostyle, odontophore, total stylet length and a few other characters. Phylogenetic analysis of the D2-D3 expansion segments of 28S rRNA gene sequences placed L. patuxentensis n. sp. in a clade with L. litchi , L. fangi , L. jonesi , L. diadecturus and Longidorus sp. The D2-D3 sequence of L. patuxentensis n. sp. was identical to that of Longidorus sp.5 collected from Juglans sp. growing in Butte County, California, USA. The D2-D3 of 28S and ITS1 rRNA and COI gene sequences indicated that the Maryland and California populations belong to the same species, described herein as L. patuxentensis n. sp. [ABSTRACT FROM AUTHOR]

Summary: During nematode surveys in natural vegetation, a new species, described herein as Trichodorus marylandi n. sp., was identified in addition to Paratrichodorus species and Nanidorus minor from Maryland, USA, and three putative new Trichodorus species from California. Trichodorus marylandi n. sp. is about 1 mm long with a medium-sized onchiostyle 54 (47-59) μ m long. Males are characterised by a single ventromedian cervical papilla located anterior to the secretory-excretory pore, all three ventromedian precloacal supplements located anterior to the retracted spicules, and spicules 42 (38-44) μ m long showing a minor indentation at the level of the posterior border of the capsule of the protractor muscles. Females possess a short barrel-shaped vagina when the body is relaxed, and two sublateral body pores on each side, one up to four body diam. anterior to the vulva and one advulvar in position. A rare observation of a 'hood' ventrally attached to a moulting male juvenile was observed and illustrated. Trichodorus marylandi n. sp. is morphologically closest to T. obtusus. Based on recent information gained from molecular data for Trichodorus species that has revealed the occurrence of several cryptic species, T. proximus is temporarily accepted as a valid species until molecular data become available from topotype specimens. Phylogenetic relationships within trichodorids, as inferred from the analyses of the D2-D3 expansion segments of 28S rRNA and ITS2 rRNA gene analysis and a statistical parsimony network showing the phylogenetic relationships between COI haplotypes of T. obtusus and T. marylandi n. sp., are also provided. [ABSTRACT FROM AUTHOR]