沟环线虫属一新种-合川沟环线虫(垫刃目:环科)

合川沟环线虫Ogma hechuanensis n.sp.采自四川合川县柑桔根围土壤中，该种雌虫体较长，R＝64－74。第一头环直矩大于第二环。头体间缢缩明显。体中部鳞片列通常为11－12。鳞片近方形，近阴门处其先端呈锯齿状。口针长116．54－13．7．91μm,Rexp=19-22。阴门、肛门距尾端近，Rv=5-7，Ra=2－4。尾端钝，具数个鳞片，与近似种O.querci在以上特征上可相区别。

A NEW CRICONEMATID NEMATODE,OGMA HECHUANENSIS N.SP.(TYLENCHIDA: CRICONEMATIDAE) IN CHINA

Ogma hechuanensis n. Sp. was Collected from soil around roots of Citrus sp. in Hechuan County, Sichuan Province, China. This species differs distinctly from all the other Ogma spp. described.Female body longer, 751~967um, gently curved ventrad. Lip region rounded with four large submedian lobes. Head annuli two, smooth and set off from the body. The first annulus, divided into 4, 5 or 8 sectors (usually 4), much larger than the second in diameter, but smaller than the third one (the first body annulus). On the third annulus 8-10 scales presrnt. The number of rows increases to 10-13 (regularly 11-12) in the middle of the body and decreases at the vulva region. Stylet stronger, 117-138um long while cone is 85-105um. Distance from head end to excretory pore, to the end of esophagus and to vulva 225-286 (253), 167-211 (192) and 678 -884 (777) um, respectively. Ovary extends forward and some even exceed stylet knob. R = 64-74 (69). Rcxp= 19~22 (21). Vulva and anus near tail end, Rv = 5-7 (6), Ra= 2-4 (3). Tail tip rounded with several scales. (2 = 9.5-13.6 (11.7), b= 3.9-4.8 (4.4), c = 17.7-33.7 (23.3), v= 88.9-92.6 (90.9).Male and juvenile forms unknown.Ogma hechuanensis n. sp. is related to O. querci, but differs in the diameter of two head annuli, rows of scales in middle body, stylet length, R, and other characteristics.Type habitat and location: soil around roots of Citrus sp. in Hechuan County, Sichuan Province, China.All slides are deposited in the Lab. of Forest Pathology, Inst. of Forest Res., Chinese Academy of Forestry, Beijing, China.