RESUMEN
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.
RESUMEN
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.