New Species

Stock-SP; Somsook-V; Reid-AP 1998 Steinernema siamkayai n. sp. (Rhabditida: Steinermatidae), an entomopathogenic nematode from Thailand. Systematic-Parasitology. 1998, 41: 2, 105-113; 19 ref. Department of Nematology, University of California Davis, 1 Shields Avenue, Davis, CA 95616-8668, USA.
AB:S. siamkayai sp. nov. is a new entomopathogenic nematode isolated in Lohmsak, Thailand. Morphology, hybridisation and molecular studies indicated the distinctness of S. siamkayai from other Steinernema spp. Diagnostic characters included: the total body length (398-495 µm) and tail length (31-41 µm) of the 3d-stage infective juvenile and lateral field pattern with 6-8 longitudinal ridges; the presence of a tail mucro in both first and second generation females and males; the size and shape of the spicules and gubernaculum, and the arrangement of the genital papillae of the first and second generation males; and the shape of the vulva and tail of the first generation female and second generation female.

Mamiya-Y. 1988. Steinernema kushidai n. sp. (Nematoda: Steinernematidae) associated with scarabaeid beetle larvae from Shizuoka, Japan. Applied-Entomology-and-Zoology, 23: 3, 313-320.
AB: S.kushidai sp. nov. is described from the cadavers of scarabaeid beetle (Anomala cuprea) larvae which were reared in soil collected in Hamakita, Shizuoka, Japan and used as bait. This new species is closely related to S. feltiae and S. intermedium (Neoaplectana intermedia), but is distinguished from them by the distance from the head to the excretory pore of all stages, the shape of spicules (heavy, curved, with round manubrium, distal tips blunt) and gubernaculum (narrow distally, bow-shaped, constricted at posterior part to round proximal portion in lateral view) of males adults, and the body length of the infective 3rd-stage juveniles (L = 524-662 µ m). The life cycle of S.kushidai is comparable to that generally accepted for the genus, but characterized by a rare production of second generation adults. The nematode was successfully maintained on either dog food agar or chicken offal medium.

Pham-Van-Luc; Nguyen-KB; Reid-AP; Spiridonov-SE 2000 Steinernema tami sp. n. (Rhabditida: Steinernematidae) from Cat Tien Forest, Vietnam. Russian-Journal-of-Nematology. 2000, 8: 1, 33-43; 14 ref.
AB:Steinernema tami sp. nov. from unknown host in Cat Tien Forest, Vietnam has characteristics of species in the "carpocapsae" group (IJ3 body length <600 µm). It can be distinguished from species in this group by the mean IJ3 body length (530 µm), which is shorter than that of S. kushidai, S. scapterisci, S. carpocapsae and S. abbasi (589, 572, 558, and 541 µm) but longer than that of S. rarum, S. ritteri and S. siamkayai (511, 510, and 446 µm). In the male, the spicule of the new species (77 µm) is shorter than that of S. scapterisci (83 µm) but longer than that of all other species in the group (<75 µm); ratio SW (spicule length/anal body width) of the first generation male (2.0) is smaller than that of S. scapterisci (2.5) but greater than that of other species (<1.8). Steinernema tami sp. nov. is further differentiated from other species in the group by the profiles of at least 3-4 enzymes in rDNA-RFLP analysis.

Mracek-Z. 1994. Steinernema kraussei (Steiner, 1923) (Nematoda: Rhabditida: Steinernematidae): redescription of its topotype from Westphalia. Folia-Parasitologica. 1994, 41: 1, 59-64. AB:The nematode S. kraussei was rediscovered in the type locality near Neuenherrsee in Westphalia, Germany. This isolate is morphologically identical with that described in 1923 by G. Steiner. Steiner's original description is completed by these main characters: the head with 2 circles of papillae, the labial bearing 6 and the cephalic 4 papillae; the excretory pore opening of adults is situated far in front of a nerve ring; the male tail has a fine mucron, spicules are on average 49 µ g long in first generation, their manubrium having the ratio length to width 1:1; spicule reticulum is usually well developed, gubernaculum varies in its shape, but mostly is boat-shaped with hooked proximal part. Infective juveniles are 797 to 1102 µ g long and their lateral fields have 8 ridges, but the central pair is less distinct and sometimes tends to merge into one unpaired ridge. Since S. kraussei is the oldest, and now the most completely described nematode species in the genus Steinernema, it has to be considered as the type species of this genus. The living culture is presently maintained in several laboratories and all formerly and future described similar species should be compared with this nematode.

Mracek-Z; Hernandez-EA; Boemare-NE. 1994. Steinernema cubana sp. n. (Nematoda: Rhabditida: Steinernematidae) and the preliminary characterization of its associated bacterium. Journal-of-Invertebrate-Pathology. 1994, 64: 2, 123-129.
AB: Steinernema cubana sp. nov. from Cuba is described. The nematode was isolated from soil samples in citrus plantations. This nematode and Steinernema glaseri and S. anomali constitute a morphological group of closely related species; however, no fertile crosses were observed among these three species. Infective juveniles of S. cubana are very long, averaging 1283 µ m and ratios D = 0.7 and E = 1.6, higher than those in S. glaseri and S. anomali. The excretory pore of adults is located close to the nerve ring or more posterior to the mid part of the basal bulb of the oesophagus. The mucron is absent on the male tail. The spicule tip is blunt, without a hook-like structure. The manubrium varies in its shape; its length to width ratio is 1.5 to 1. S. cubana can be cultured on G. mellonella larvae. The bacterial symbiont belonging to the genus Xenorhabdus is a gram-negative rod-shaped bacterium. The cell size ranges from 0.4X2.0 to 2.0X5.0 µ m.