Acrostichus puri n. sp., isolated from the body of a sweat bee, Augochlora pura mosieri, is described and figured. The new species is morphologically, molecularly and biologically very similar to A. halicti, i.e., these two species share a very complicated gubernaculum structure, distally hooked spicules with a triangular flap-like rostrum, stomatal polymorphism and synchronised associations with halcitid bees. The new species can be distinguished from A. halicti by its spicule morphology, distinctive squared manubrium and sharply bent (= ca 90° or L-shaped) distal tip vs an indistinctive rounded manubrium and a strongly recurved (= ca 180° or U-shaped) distal tip; gubernaculum with narrower, longer, anterior part and more complex posterior part than A. halicti, and tail of both sexes, with a long and filiform spike on the male or female tail vs a short spike (male) or conical tail (female). These two species also differ from each other by significant molecular sequence differences in SSU (2.0%), D2/D3 LSU (4.5%) and mtCOI (9.2%), and are reproductively incompatible in mating tests.

Taxonomy and morphology of plant-pa rasitic nematodes associated with turfgrasses in North and South Carolina, USA

An emerging threat to agriculture, Meloidogyne enterolobii Yang & Eisenback, 1983, is a tropical species and considered to be the most damaging root-knot nematode (RKN) in the world because of its wide host range, aggressiveness, and ability to overcome resistance to RKN in many crops. It was first detected in the United States on ornamental plants in Florida in 2001 but has since been identified in North Carolina, South Carolina, and Louisiana. Several thousand RKN populations were collected from North Carolina field crops, ornamental plants, and turfgrasses for species identification in the Nematode Assay Laboratory in the North Carolina Department of Agriculture & Consumer Services. From 2006 to 2019, root systems showing galling symptoms were dissected under the microscope, and females were obtained for DNA analysis. When only soil samples were submitted, the second-stage juveniles or males were used instead. Molecular characterization was performed via polymerase chain reaction with species-specific primers and DNA sequencing on the ribosomal DNA 18S-ITS1-5.8S and 28S D2/D3 and mitochondrial DNA CoxII-16S. One hundred thirty-five representative RKN populations from North Carolina were characterized and identified as M. enterolobii. Six populations from China where the species was originally described were included in this study for identity confirmation and comparison. As of December 2019, M. enterolobii has been confirmed from a limited number of fields in 11 North Carolina counties: Columbus, Craven, Greene, Harnett, Johnston, Lenoir, Nash, Pitt, Sampson, Wayne, and Wilson. Currently, M. enterolobii is the most important emerging RKN species in the United States and causes severe damage to agronomic and horticultural crops, especially sweetpotato in North Carolina.

A new nematode species was recovered from the syconia of Ficus altissima from the residential area of Huajingxincheng, Guangzhou, Guangdong Province, China during a survey of nematode diversity. Schistonchus altissimus n. sp. is characterised by having females with a short post-uterine sac, an ovoid spermatheca and a conoid tail with a mucron in the female, excretory pore located near the lip; and males with amoeboid sperm, a conoid tail without a mucron and three pairs of subventral papillae, no gubernaculum, and hook-shaped spicules with a cucullus and a thorn-shaped rostrum. Schistonchus altissimus n. sp. is typologically differentiated from all other described species in this genus, except for S. microcarpus, by having a spicule with cucullus on the male tail tip. Schistonchus altissimus n. sp. is easily differentiated from other sequenced species by the partial small subunit rRNA gene (SSU), D3 expansion segment of the large subunit rRNA gene (LSU) and mitochondrial DNA subunit I (mtCOI). Phylogenetic analysis with partial SSU sequences suggests that S. altissimus n. sp. is in a highly supported monophyletic clade with two Chinese species (S. microcarpus and S. centerae) and two neotropical species (S. aureus and Schistonchus sp. ex Ficus colubrinae Standl.). Based on inferences using LSU D3 sequence data, S. altissimus n. sp. has a closer relationship with four Chinese species (S. centerae, S. fistulosus, S. guangzhouensis and S. microcarpus) than with S. hirtus and S. superbus, also from China.

A new nematode species was recovered from the syconia of Ficus superba from the South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong Province, China, during a survey of nematode biodiversity from 2007 to 2012. It is described herein as Schistonchus superbus n. sp. and is characterised by possessing the combined characters of a short post-uterine sac and digitate tail without a mucron in females, excretory pore located near the metacorpus, amoeboid sperm, a unique wedge-shaped male tail with variable tip and two pairs of subventral papillae, absence of a gubernaculum and possession of sickle-shaped spicules without a cucullus and with a thorn-shaped rostrum. Schistonchus superbus n. sp. is typologically differentiated from all other described species in this genus by the possession of a wedge-shaped tail in males and a digitate tail without mucron in females. Schistonchus superbus n. sp. was easily differentiated from other sequenced species by the partial small subunit rRNA gene (SSU), D3 expansion segment of the large subunit rRNA gene (LSU) and mitochondrial DNA subunit I (mtCOI). Phylogenetic analysis with partial SSU sequences suggests that S. superbus n. sp. is sister to S. caprifici and S. hirtus, and is a polyphyletic relative to other Schistonchus species that have been sequenced. Based on inferences using LSU D3 sequence data, S. superbus n. sp. is in a well-supported monophyletic clade with S. caprifici, S. hirtus and S. macrophylla.

The turfgrass industry has undergone a rapid development in Guangdong province, China, which has the largest number of golf courses in the country. Recent surveys of turfgrasses in the province revealed five plant-parasitic nematodes that are prevalent: Helicotylenchus dihystera, Mesocriconema xenoplax, Meloidogyne graminis, Hemicriconemoides rosae and Tylenchorhynchus leviterminalis. The most prevalent species are M. xenoplax and M. graminis, found in 60.6% and 27.3% of locations, respectively. These five species are morphologically and morphometrically described. Molecular characterization and phylogenetic analyses using 18S rRNA and the D2-D3 expansion segments of 28S rRNA sequences are provided. This is the first report on molecular characterization and phylogenetic relationships of plant-parasitic nematodes associated with turfgrasses in Guangdong, China. This work was a first step for future study including pathogenicity assay, relationship examination with other pathogens and development of control measures of these turf nematodes to provide more precise and effective management options to turf superintendents.