Description of grandaspicatus n. sp. (Nematoda: Dolichodoridae) ~ R. T. ROBBINS ~ Abstract: Dolichodorus grm~daspicatus n. sp., collected from soil about roots of a red maple (Acer rubrum L.) in a creek bonom near Ludwig. Johnson County, Arkansas, is described. It differs from two closely related species, D. marylandicus and D. heterocephalus, by the longer spike on Ihe female tail, the length of the female tail, and the shape of the extrudable portion of the gubernaculum of the males. It further differs front D. marylandicus by having heavily sclerotized accessory pieces nf the vulva and from D. heterocephalus by having a shorter styler. Key words: taxonomy, morphology, new species. Journal t)f Nematology 14(4):507-511. 1982.

There are 10 described species of standard deviation, and coefficient of varia- l)olichodorus. Lewis and Golden (2) rec- tion (as a percentage) in parentheses. Only ently published a key to nine of the species mean and range given in descriptive text. with reference to literature pertinent to the The specific name is derived from the Latin genus and to the sub-family Dolichodorinae. words granda (large) and spica (spike). Jairajpuri and Rahmani (1) described the species D. kishansinghi, which was not in- DESCRIPTION clutled in the above. Dolichodorus grandaspicatus n. sp. In July 1979 samples were taken from a creek bottom near Ludwig, Johnson MEASUREMENTS (16 ~ 2 paratypes): County, Arkansas, to find and identify a Length = 2.40 mm (2.13-2.65; 0.17; 7.2); Dolichodorus species found in the general width = 38.1 (33-42; 3.0; 7.9); a = 63.0 area by Dr. R. D. Riggs a few years earlier. (56.1-76.7; 6.2; 9.8); b = 10.1 (9.2-11.0; In one sample a few specimens of an unde- 0.6; 6.0); c = 27.4 (22.6-34.6; 3.2; 11.6); scribed species of Dolichodorus were re- c' = 2.6 (2.0-3.4; 0.36; 13.5); V -- 54.3 covered. A later sample from about the (51.4-56.3; 1.4; 2.6); stylet = 89.6 (84-93; roots of red maple (Acer rubrum L.) yielded 2.7; 3.1); stylet conus = 53.4 (48-60; 4.0; numerous specimens of both sexes as well as 7.4); distance from anterior end to excretory second-, third-, and fourth-stage juveniles. pore (ex.p.) ---- 170.2 (152-186; 10.0; 5.9); tail = 88.4 (68-106; 9.6; 10.8). MATERIALS AND METHODS HOLOTYPE (9): Length = 2.58 mm; a = 64.6; b = 11.1; c = 31.5; c' ~ 2.42; V Specimens were killed and fixed by hot = 54.5; stylet = 90.6; stylet conus = 53.8; 2% formalin and processed to glycerin by distance from base of stylet to dorsal esoph- a modified Seinhorst rapid method as de- geal gland orifice (DGO) = 5.3; distance scribed by Robbins (3). Specimens were from anterior end to median bulb valve prepared for SEM observation by gold coat- (MBV) = 141; ex. p. = 171; distance from ing glycerine impregnated specimens using anterior end to hemizonid (hemizonid) -- the method of Sher and Bell (4). Observa- 194; distance from anterior end to hemi- tions were made on an ISI-60 SEM. zonion (hemizonion) = 216; spike length In the following description, all meas- = 66; annule width = 1.6-1.7. urements are given in t~tn, unless otherwise DESCRIPTION OF FEMALE (para- stated; ratios and counts have no units. types): Body vermiform, slightly arcuate. Means are given first, followed by the range, Lip region prominent, markedly offset from body (Figs. 1A, 2C), with 5-6 very fine in- Received for Publication 9 March 1982. ~Published with approval of the director of tile Arkan- conspicuous lip annules. Lip region en face sas Agricultural Experiment Station. with four lobes, a slightly oval oral disc ~Assistant Professor, Department of Plant Patholo~', University of Arkansas, Fayetteville, AR 72701. (Fig. 2A), strong cephalic framework, and Appreciation is expressed to Dr. S. A. Lewis, Associate heavily sclerotized basal plate. Amphids Professor of Plant Pathology'. Clemson University, for pro- viding specimens, to E. M. Martin. Research Assistant, lateral, longitudinal slits. Cephalids as University of Arkansas. for SUM technical help, anti to shown (Fig. 1A). Stylet conus 60% of stylet Dr. R. D. Riggs, Professor of Plant Pathology, University of Arkansas. for suggesting areas to sample. length, stylet knobs rounded, directed pos-

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Fig. 2. SEM pictures of Dolichororus granctaspzcatus n. sp. A) l:emale en lace. B) Male tail. dorsal. C) Female, oblique head. D) Female tail, dorsal. E) Female, anus. teriorly. Excretory pore clearly visible, vari- tine canals conspicuous in most specimens. able in position, from mid-median bulb to Tail, when viewed laterally, with "shoul- anterior basal bulb. Hemizonid 24.8 (13-36) ders," tapering to a spike which may be posterior to excretory pore. Hemizonion acute or rounded (Figs. IE-F, 2D). Tail, inconspicuous, about as far posterior to when viewed dorsally or ventrally, with- hemizonid as semizonid is from ex. p. Vulva out "shoulders," origin of spike incon- a transverse slit (Fig. 1C-H), with sclerot- spicuous (Figs. 1F, 2D). Most tails end in ized, opposed, accessory pieces observed in a small mucor (Figs. 1B-E, G, 2B), others lateral view (Fig. 1G). Vagina strongly acute to conical rounded. Anus a transverse sclerotized near vulva. Vagina about half slit (Fig. 2E). Anal body width 33.8 (30-38). the body width. Ovaries amphidelphic, out- MEASUREMENTS (18 8 8 paratypes): stretched. Spermatheca oval, conspicuous, Length = 2.13 mm (1.88-2.44; 0.14; 6.7); ;it proximal end of oviduct. Cuticle with width = 33.8 (27-39; 3.1; 9.1); a ---- 63.3 annules slightly wider at level o[ excretory (55.9-73.7; 5.0; 7.9); b = 9.3 (8.7-10.6; 0.4; pore (~ 1.8) than at mid-body (~ 1.5). 4.6); c -- 70.1 (62.2-81.0; 5.1; 7.3); stylet ---- Lateral field with three lines, completely 84.8 (78-90; 3.5; 4.1); stylet conus = 50.7 areolated. Midline starts about two lip (44-55; 2.8; 5.6); spicules = 40.4 (36-44; widths from anterior end, extends to 2.1; 5.3); gubernaculum = 23.9 (22-27; phasmid, outerlines start in region of me- 1.3; 5.4); tail = 30.6 (24-34; 2.9; 9.6); ex. p. dian bulb, extend to level of anus. Serpen- = 161 (136-190; 13.2; 8.2).

.~ IIIII \\\\\ Fig. 1. Dolichodorus grandaspicatus n. sp. A) Female anterior. B) Second-stage juvenile tail. C) Third- stage tail. D) Fourth-stage tail. E) Female tail, lateral. F) Female tail, ventral. G) Vulva region, lateral. H) Vulva region, ventral. I) Cross section through ovary. J) Male tail. K) Spicule. L) Gubernaculum and ac- cessory strncture. 510 Journal o[ Nematology, Volume 14, No. 4, October 1982 ALLOTYPE (~): Length = 2.16 mm; Voor Nematologie, Wageningen, The a = 59; b = 9.4; c = 83; stylet = 89.7; Netherlands; Laboratorie des vers, Mu- stylet conus = 53.8; DGO = 4.4; MBV = seum, 61 Rue de Buffon, Paris, France; 133; spicules = 38; gubernaculum = 21.3; Institute voor Dierkunde, Laboratirum tail = 26; ex. p. = 179; hemizonid = 201; voor Morfologie ell Systematiek der Dieren, annule width = 1.4 (mid-body), 1.8 Ledeganckst, 35, B-9000, Gent, Belgium; (median-bulb region). Canadian National Collection of Nema- DESCRIPTION (~ ,~): Body similar to todes, Ottawa, Canada; remaining speci- female in head shape, annule width, lateral mens retained in the author's collection. lines (except tail regions); however, slightly TYPE HOST AND LOCALITY: Soil smaller with posterior region (20%) from about the roots of red maple (Acer markedly more curved than anterior region rubrum L.) in a sandy-silt creek bottom (80%), and with bifurcate tail terminus. with high organic matter, one mile north Caudal alae typical for the genus. Testis atnl one mile east of Ludwig, Johnson outstretched. In lateral view, gubernaculum County, Arkansas, USA. with extrudable, slightly curved distal end DIAGNOSIS: Dolichodorus granda- that is characteristically hook shaped (Fig. spicatus n. sp. is more similar to D. mary- I J, L); accessory structure interposed with landicus Lewis g: Golden 1981 and D. adjacent spicule (Fig. 1J). heterocephalus Cobb 1914 than the other JUVENILES (J-2, n -- 14; J-3, n = 14; Dolichodorus spp. It differs from both spe- J-4, n = 14), measurements: See Table 1. cies by the much longer tail and spiked DESCRIPTION (J-Z, J-3, J-4): Body portion of the female tail. It further differs similar to female in overall shape, head from D. marTlandicus females by the nar- shape. Tails with definite spike, generally rower body, 38 (33-42) vs. 45.3 (39.2-54.6) ; with definite mucor at terminal end. Ser- "a" ratio, 63.0 (56.1-76.7) vs. 45.5 (36-54); pentine canals conspicuous in most speci- "c" ratio, 27.4 (22.6-34.6) vs. 38.8 (30.2- mens (Fig. 1B-D). 51.4); and by having a heavily sclerotized HOLOTYPE (9): Collected 15 October structttre exterior to the heavily sclerotized 1979 by R. T. Robbins. Slide T-354t, USDA distal portion of the wdva. It further differs Collection (USDANC), Belts- from D. heterocephalus females by having ville, Maryland. a shorter stylet 90 (84-93) vs. 99 or more. ALLOTYPE (3): Same data as holo- The males differ from both the above spe- type. Slide T-355t, USDANC, Beltsville. cies by the characteristically hook shaped PARATYPES (9 9, ~ d, juveniles): extrudable portion of the gubernaculum. USDANC, Beltsville, Maryland; California Nematode Survey Collection, Davis; De- LITERATURE CITED partment of Nematology Collection, River- side, California; Nematology Department, 1. Jairajpuri, M. S., and S. A. Rahmani. 1979. Dolichodorus kishansinghi n. sp. (Nematoda: Rothamsted Experimental Station, Hat Dolichodoridae). Indian J. Nematol. 7:183-185. penden, Herts., England; Laboratorium 2. Lewis, S. A., and A. M. Golden. 1981. De- Table 1. Measurements, in #m, and ratios of second-, third-, and fourth-stage juveniles of Dolichodorus grandaspicatus 11. sp.

Measurement Stage of juveniles or ratio Second (n = 14) Third ( = 14) Fourth (n = 14)

Length 676 (611-785)* 1,075 (944-1,245) 1,627 (I ,412-2,038) a 39.8 (34.1-43.9) 49.5 (41.0-57.5) 55.8 (47.3-62.7) b 4.6 (4.3-5.1) 6.0 (5.2-6.9) 7.7 (7.2-9.2) c 13.0 (11.0-14.5) 15.4 (13.5-18.0) 21.8 (17.4-25.3) Stylet 46.1 (43-48) 62.5 (60-66) 77.9 (74-86) Width 17.1 (15-20) 21.8 (19-24) 29.3 (24-36) Tail 52.2 (4C~-60) 70 (64-78) 75 (@0-90)

*Mean followed by range in parentheses. Dolichodorus grandaspicatus n. sp.: Robbins 511 scription and SEM observations of Dolichodorus 10:28-34. marylandicus n. sp. with a key to species of 4. Sher, S. A., and A. H. Bell. 1975. Scanning Dolichodorus. J. Nematol. 13:128-135. electron micrographs of the anterior region of 3. Robbins, R. T. 1978. Descriptions of females some species of (: Nema- (emended), a male, and juveniles of Paralongidorus toda). J. Nematol. 7:69-83. microlaimus (Nematoda: Longidoridae) J. Nematol.

Morphological Comparisons Between Xiphinema rivesi Dalmasso and X. americanum Cobb Populations from the Eastern United States'

.X'|AREK 1"~. ~¥OJTOWICZ'-', A. MORGAN GOLDEN :~, L. B. FORER 4, AND R. F. STOUFFER r' Ab.~tract: Tltough in the past Xiphinema americanum has been the most commonly reported dagger nematode in the eastern United States, our studies revealed the presence in l'ennsvlvania of a previously tntrecognized and unreported species related to X. americanum, Morphometric data atul photomicrographs establish the identity of this form as X. rivesi and show expected variations in populations of this species from various locations. Similar data and illustrations are given for X. americam~m populations from Pennsylvania and other areas, showing variations attd relationships. Xiphinema rivesi is widely distributed in the fruit producing area of south- cctttral l'cttnsylvania atttl is also reported herein from raspherry in Vermont and apple in Maryland attd New York. This species is frequently found it, fruit growing areas of Pennsylvania associated with lomatn r'ngspot virus-induced diseases and is also found associated with corn, bluegrass sod, and alfalfa. Key words: Xiphinema amerieanum, X. rivesi, morphology, occurrence, fruit orchards, virus transmission. Journal of Nematology 14(4):511-516. 1982.

A previously unrecognized, didelphic vestigated. Preliminary results indicate that species of the nematode genus Xiphinema this previously unidentified species of Xi- Cobb, 1913 was isolated by the senior phinema is able to transmit TmRSV (3), attthor in 1977 from soil in a southcentral and its presence in fruit orchards, alone or Pennsylvania (Adams County) apple or- in species mixtures, has complicated dagger chard. Since the initial isolation, the spe- nematode identifications, especially in virus cies has been isolated frequently from peach transmission research. This report primarily and apple orchards, grape vineyards, and provides morphological data and details of soft fruit plantings as well as alfalfa, corn, the newly isolated Xiphinema species iden- and bluegrass in this particular area of tified herein and the related and commonly Pennsylvania and from fruit growing areas occurring species, X. americanum Cobb, in nearby states. Many of the sites where 1913. this nematode has been found have a his- tory of tomato ringspot virus (TmRSV) MATERIALS AND METHODS problelns in the fruit crops. The possible association between this species of Xiphi- Soil samples were taken with an Oak- nema and TmRSV disorders is being in- field soil probe to a depth of approximately 23-30 cm, depending on soil condition and Received for publication 16 March 1982. texture. Multiple probes were combined to ~This research was funded in part by Agricultural Re- give a composite sample of approximately search Project Contract :~614498 trom the Pennsylvania l)epartmeot of Agriculture, Bureau of Plant Industry. 550 cm ~. Each composite sample was eVisiting Scientist, Pennsylvania State University, Fruit Research Laboratory, Biglerville, PA 17307. Present address: thoroughly but gently mixed, a 100-cm3 Research Institute of Pomo[ogy and Floriculture, 96-100 subsample was taken, and the Skierniewice, Poland. '~Nematologist, Nematology Laboratory, U.S. Department extracted by a modification of the decant- of Agriculture, ARS, BARC-West, Beltsville, MD 20705, ing and sieving technique described by 4Nematologist, Pennsylvania Department of Agriotltnre, Bureau of Plant Industry, Harrisburg. PA 17110. Flegg (2). The extracted nematodes were ~l'rofessor, Department of Plant Pathology, Pennsylvania killed with a 3.4% hot formaldehyde solu- State University. Fruit Research Laboratory, Biglerville, PA 17307. tion, fixed in formalin/acetic acid fixative,