Measurements (n = 20) : Length=7390 (5200-10400) micrometers (um); greatest width =169 (132-216) um ; length of stoma = 9 (6.5-12) um; width of stoma =11 (9-12.5) um ; esophagus length = 219 (205-250) um, anterior end to excretory pore =93 (65-113) um, to nerve ring =163 (132-183) um ; V =57% (52-66); length of tail =44 (37-50) um; width at anus =84 (65-110) um; length of mucron = 5 (4-6) um .
Females, second generation : Similar to first generation but body smaller and tail longer.
Males, first generation : Cuticle, lip region and esophageal region similar to those of other species. Testis single and reflexed. Spicules paired, heavy, symmetrical, curved, with ribs. Capitulum round. Velum thin. Spicule tip usually blunt. Gubernaculum variable in shape , anterior end usually curved ventrally. Tail with 21 genital papillae. The single precloacal papilla present sometimes, but usually paired in this nematode. Tail conical, tapering to a fine mucron. Bursa absent.
Measurements (n = 20) : Length = 1600 (1300-1700) um; greatest width = 123 (100-142) um; length of stoma = 3 (2-5) um; width of stoma = 4.5 (3-5) um; esophagus length = 135 (125-150) um; anterior end to excretory pore = 67 (55-77) um, to nerve ring = 103 (91-120) um; testis reflexion = 347 (175-543) um; length of tail = 43 (35-52) um ; width at anus = 50 (40-57) um; length of spicule = 48 (42-52) um; width of spicule = 7 (5.5-9) um; length of gubernaculum = 34 (23-38) um; length of mucron = 3 (2-5) um.
Males, second generation : Similar to first generation but smaller size, thinner spicules and tail with a well developed mucron.
Infective juveniles : Body slender, tapering to both ends, usually with sheath. Cuticle with fine striae. Lateral field with six ridges. Lip region smooth, generally not set off. Mouth and anal openings closed. Esophagus long and narrow, distinctly narrower at level of nerve ring, terminating in a valvated basal bulb displaced dorsally. Cardia present. A bacterial pouch present in intestine, posterior to cardia. Lumen of intestine narrow and closed. Rectum long and narrow. Anus distinct. Excretory pore in first half of esophagus. Excretory duct long, usually distinct; ventral excretory glands displace the basal bulb, bacterial pouch and anterior end of intestine dorsally. Nerve ring distinct, anterior to basal bulb. Hemizonid at level of basal bulb. Genital primordium well developed, in the middle of the posterior half of the body. Tail conical with pointed terminus.
Measurements (n = 20): Length = 499 (443-563) um ; greatest width = 22 (19-26) um; esophagus length = 96 (89-105) um; anterior end to excretory pore = 37 (34-40) um; to nerve ring = 66 (60-72) um, to hemizonid = 74 (70-79) um; length of tail = 49 (43-55) um.
Type hosts and habitat : In the body cavity of Heliothis sp. (Lepidoptera Noctuidae).
Type locality : Rio Cuarto, Province of Cordoba, Argentina.
Type specimens Holotype
: female, on slide RAX/171-6, deposited in the Centro de Zoologia Aplicada,
Universidad Nacional de Cordoba, Argentina.
Paratypes : specimens distributed as follows: five females and
five males of first generation in Station de Recherches sur les Nematodes,
INRA, Antibes, France and in University of California, Davis, Ca, USA.
Remaining specimens deposited in the Centro de Zoologia Aplicada.
Diagnosis and relationships Steinernema rarum can be separated from all other species of the genus by short body of infective juveniles and short spicules of males. Morphology of the spicules of S. rarum is close to S. carpocapsae
REFERENCE.
Doucet, M. M. A. 1986. A new species of Neoaplectana Steiner,
1929 (Nematoda:
Steinernematidae) from Cordoba, Argentina. Revue de Nematologie 9:317-323.
This document was constructed and is maintained by KHUONG
B. NGUYEN
Entomology & Nematology Department
University of Florida