Revision of the Genus Pratylenchoides Winslow, 1958 (Nematoda: Tylenchoidea)

154 PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY

S. A. SHER Department of Nematology, University of California, Riverside, California 92502

ABSTRACT: The history of the genus Pratylenchoides' Winslow, 1958 is presented and an emended diagnosis of the genus given. The three nominal species are redescribed and illustrated from type specimens, and four new species are proposed. A key to the species is presented. The morphology, geographical distribution and biology of Pratylenchoides are discussed in relation to the most closely related taxon, Radopholus Thorne, 1949.

The genus Pratylenchoides Winslow, 1958 ferred the species Pratylenchoides gadeai Arias, was proposed for the nematode described by Jimenez and Lopez, 1965 to the genus Tylen- Goodey (1932, 1940) as Anguillulina obtusa chorhynchus Cobb, 1913. (Bastian, 1865) Goodey, 1932 and placed in Pratylenchoides maritinus Bor and s'Jacob, the subfamily Pratylenchinae. Pratylenchoides 1966 was described as differing from the other was distinguished by Winslow from Pratylen- two species in this genus by the long dorsal chus Filipjev, 1934 by its didelphic character, esophageal overlap of the intestine, the low lip and from Radopholus Thorne, 1949 by the region, shape of the female tail, the great size short oblique overlapping esophageal glands. difference between females and males and by A second species was described in this genus, the median bulb, which is as strongly developed Pratylenchoides guevarai Tobar Jimenez, 1963 in the males as in the females. They were in as differing from the type in having a tail agreement with Braun and Loof (1966) that the terminus without annulation and the esopha- following do not belong in Pratylenchoides: P. geal glands overlapping the intestine, ventrally. guevarai Tobar, 1963; P. taomasinae (de Tarjan and Weischer (1965) synonymized Guiran, 1964) Tarjan and Weischer, 1965; and the genera Zygotylenchus Siddiqi, 1963 and P. gadeai Arias, Jimenez and Lopez, 1965. Mesotylus de Guiran, 1964 with Pratylen- In 1967, de Guiran and Siddiqi differenti- choidefi. They also considered Zygotylenchus ated Pratylenchoides from Zygotylenchus by browni Siddiqi, 1963 and Mesotylus gallicus the structure, position and length of the esoph- de Guiran, 1964 synonyms of Pratylenchoides ageal glands overlapping the intestine. guevarai Tobar Jimenez, 1963 and transferred The present study was undertaken to diag- Mesotylus taomasinae de Guiran, 1964 to Pra- nose the genus and differentiate it from the tylenchoides taomasinae (de Guiran, 1964) genera Radopholus and Zygotylenchus and to Tarjan and Weischer, 1965. identify the numerous specimens in the Uni- Pratylenchoides gadeai Arias, Jimenez and versity of California at Biverside collection. Lopez, 1965 was described from Spain. Braun Type material of all the described species and Loof described Pratylenchoides laticauda has been available for study, as well as that in Braun and Loof, 1966 and considered Praty- the closely related genera, Radopholus and lenchoides a genus distinct from Zygotylenchus Zygotylenchus. Over 1,500 specimens of Pra- (Syn. Mcsotylus). They pointed out the dif- tylenchoides, in permanently mounted glycer- ferent type of esophagus, absence of a deirid ine slides, from many areas of the world, have and lack of sexual dimorphism in the esophagus been used in this study. Fresh specimens in of Zygotylenchus. Pratylenchoides taomasinae water and 2% formalin have been examined (de Guiran, 1964) now became Zygotylenchus for the proposed new species. taomasinae (de Guiran, 1964) Braun and Loof, 1966, and Pratylenchoides guevarai Tobar, Morphology 1963 now became Z. guevarai (Tobar, 1963) The genus Pratylenchoides resembles the Braun. and Loof, 1966. They also trans- genus Radopholus Thorne, 1949, as reported

Copyright © 2011, The Helminthological Society of Washington OF WASHINGTON, VOLUME 37, NUMBER 2, JULY 1970 155 by Sher (1968), with the differences noted in Female tail terminus striated; stylet 21 ^ the generic diagnosis and discussion. or longer 5 5. Female esophageal glands overlapping Genus Pratylenchoides Winslow, 1958 intestine over two times the body DIAGNOSIS EMENDED: Radopholinae. Labial width ritteri sp. n. framework and stylet well-developed. Sexual Female esophageal glands overlapping dimorphism present in anterior part of body, intestine one-and-a-half or less times male with slightly higher rounded lip region, the body width 6 stylet and esophagus not as developed as fe- 6. Lateral field with six incisures; lateral male. Deirids present. Esophageal glands canals conspicuous laticauda overlapping intestine ventrally, laterally and Lateral field usually with four incisures; dorsally, greatest development dorsally with at lateral canals inconspicuous least one esophageal gland nucleus above the variabilis sp. n. esophageal intestinal valve. Ovaries paired. Phasmids in posterior portion of tail. Caudal Pratylenchoides crenicauda Winslow, 1958 alae enveloping tail, gubernaculum not project- (Fig. 1A-C, E) ing from cloaca. Anguillulina ohtusa (Bastian, 1865) Goodey, TYPE SPECIES: Pratylenchoides crenicauda 1932, pp. 63-65; Goodey, 1940, pp. 34-36. Winslow, 1958. Rotylenchus obtusus Filipjev and Schuur- The genus Pratylenchoides can be distin- mans Stekhoven, 1941, p. 219. guished from the most closely related genus Pratylenchoides crenicauda Winslow, 1958, Radopholus by the characters: presence of pp. 136-138; Jairajpuri, 1964, p. 339; Tarjan deirids; esophagus with at least one esophageal and Weischer, 1965, pp. 433-439. nucleus at or above the level of the esophageal intestinal valve; less sexual dimorphism; and MEASUREMENTS: 15 9 9 topotypes: L = 0.64 the gubernaculum not projecting from the mm (0.53-0.86); a = 25 (21-29); b = 4.6 (4.1- body. In addition, Pratylenchoides shows the 5.2); b' = 4.2 (3.5-5.2); c = 15 (13-18); V = following: phasmids in the posterior portion of 58 (56-62); stylet = 22 ^ (20-23). the tail; no longitudinal striations on the lip 4$ $ topotypes: L = 0.66 mm (0.61-0.72); b' = 5.5 (5.2-5.7); stylet = 21 ^ (20-21); guber- region; usually round sperm in the sperma- naculum = 6 p. (4-7); spicules = 22 M (20-24). theca; and different geographical distribution. FEMALE: Lip region flattened, slightly or Pratylenchoides can be easily distinguished not set off, three, sometimes four annules. from Zygotylenchus by the dorsal esophageal Stylet knobs broadly rounded sloping poste- glands, which overlap the intestine, and by the riorly. Esophageal glands overlap intestine presence of deirids. about one body width (0.6-1.2). Spermatheca usually inconspicuous or not seen, or with ir- Key to the species of Pratylenchoides regularly rounded sperm. Lateral canals pres- 1. Female tail almost pointed, stylet 18 p, or ent. Lateral field with six, sometimes four shorter maritimus incisures, incompletely areolated on tail. Tail Female tail rounded, stylet 19 ^ or longer 2 tapering with 28-36 annules, annulation con- 2. Female tail with 28 or more annules spicuous around terminus. crenicauda MALE: Lip region slightly higher and narrower than female, three to five annules. Female tail with 28 or less annules 3 Esophagus and esophageal glands not as well 3. Sperm in spermatheca and testis rod-like developed as in female, overlapping intestine bacilisemenus sp. n. less than one body width. Sperm elongated, Sperm in spermatheca and testis irregu- spindle shape. larly rounded or elongated (spindle- TYPE HABITAT AND LOCALITY: Turf, Rotham- shaped) 4 sted Experimental Station, Harpenden, Herts, 4. Female tail terminus usually without England. striae, occasionally one to two striae; DIAGNOSIS: Pratylenchoides crenicauda can stylet 21 /JL or less leiocaiida sp. n. be identified by the shape and large number

Figure 1. Pratylenchoides crenicaitda. A. Female, anterior region. B. Male, anterior region. C. Female, posterior region. E. Male, posterior region. Pratylenchoides laticauda. D. Female, stylet region. F. Fe- male, posterior region. G. Male, stylet region. H. Female, surface view in region of esophageal glands. Pratylenchoides maritimus. I. Female, posterior region. J. Female, anterior region.

Copyright © 2011, The Helminthological Society of Washington OF WASHINGTON, VOLUME 37, NUMBER 2, JULY 1970 157 of annules on the female tail, short esophageal fied from the following habitats and localities: overlap of the intestine, males with elongated, soil, Athens, Greece; and carob tree soil, Bari, spindle-shaped sperm and the scarcity of males. Italy. The description of P. crenicauda is based on topotypes and specimens collected from cherry Pratylenchoides maritimus Bor and soil, East Sutton, England in March 1962. Ad- s'Jacob, 1966 ditional specimens have been identified from '(Fig. 1 I-J) grass soil, Minister, Germany; grass soil, Mel- Pratylenchoides maritimus Bor and s'Jacob, lissant and Leiderdorp, The Netherlands; grass 1966, pp. 463-465. soil, Budapest, Hungary; sandy soil, Vistula MEASUREMENTS: 5? paratypes: L = 0.54 Riverbank, Wyszogrod, Poland; and meadow mm (0.51-0.61); a = 24 (20-26); b = 4,3 (4.0- soil, Gulmarg, Srinagar, Kashmir, India. In all 4,5); b' = 3.5 (3.3-3.7); c = 13.2 (12-15); V = the populations studied, males were scarce or 59 (58-61); stylet = 17 /x. (16-18). not present. 5$ £ (after Bor and s'Jacob, 1966): L = 0.39 mm (0.31-0.42); a = 25 (24-28); b = 3.9 (3.5- Pratylenchoides laticauda Braun and 4.0); b' = 3.4 (3,3-3.5); c = 9.8 (7.8-11.1); gu- Loof, 1966 bernaculum = 5 JJL (4-5); spicules = 17 p, (16- (Fig. ID, F-H) 17); stylet = 15 ^ Pratylenchoides laticauda Braun and Loof, FEMALE: Lip region flattened anteriorly, 1966, pp. 241-244. not set off, two or three annules. Stylet knobs rounded, sloping posteriorly. Esophageal MEASUREMENTS: 72 topotypes: L = 0.81 glands overlapping intestine about one body mm (0.76-0.83); a = 28 (26-29); b = 4.7 width. Spermatheca round with irregularly (4.1-5.3); b' = 4.2 (3.8-4.5); c = 17 (14-18); rounded sperm. Lateral canals present. Lateral V = 59 (58-61); stylet = 24 ^ (23-24). field with four incisures. Tail with 28-36 an- 3$ topotypes: L = 0.77 mm (0.75-0.80); nules, tapering to almost pointed terminus, a = 28 (24-32); b = 5.8 (5,3-6.2); b' = 4.9 often with coarse irregular striations at termi- (4.7-5.0); c = 15 (14-17); gubernaculum = 9 p, nus. (8-10); spicules = 26 ^ (24-28); stylet = 21 ^ MALE (after Bor and s'Jacob, 1966): Shorter (20-22). and slenderer than female with shorter stylet FEMALE: Lip region slightly or not set off, (15 /x,). Median bulb as strongly developed as three or four annules. Stylet knobs broadly female. rounded, sloping posteriorly. Esophageal glands TYPE HOST AND LOCALITY: Soil around plant with short overlap of intestine (less than one roots, Boschplaat, Island of Terschelling, The body width). Spermatheca rounded, with ir- Netherlands. regularly rounded sperm. Lateral canals con- DIAGNOSIS: P. maritimus can be distinguished spicuous. Lateral field with six incisures. Tail from the two preceding species by the short with 18-26 annules, broadly rounded, coarse stylet, longer overlapping esophageal glands irregular stria at terminus. and the tapering, almost pointed, female tail. MALE: Lip region narrower, higher and A more complete description, illustrations more conoid. Esophagus and esophageal glands and measurements of P. maritimus are given in not as well-developed as in female. Sperm ir- the original description by Bor and s'Jacob regularly rounded. (1966). TYPE HOST AND LOCALITY: Roots of Monarda Specimens of Pratylenchoides maritimus (5 $ mollis, Huis ter Heide, The Netherlands. paratypes) have been received from the authors DIAGNOSIS: P. laticauda can be distinguished of this species and are deposited in the Nema- from the type species by the female tail, which tode Collection of the Department of Nematol- has fewer annules and a broader tail terminus. ogy, University of California, Riverside. A more complete description, illustrations and measurements of P. laticauda is given in Pratylenchoides variabilis sp. n. the original description by Braun and Loof (Fig. 2) (1966). MEASUREMENTS: 20$ paratypes: L ~ 0.58 Specimens of P. laticauda have been identi- mm (0,50-0.66); a = 30 (26-32); b = 3.9 (3.5-

D-E 0.01 mm A-C, 0.02mm F-J

4.4); b' = 3.4 (3.1-4.4); c = 16 (13-19); V = The paratypes have two to four annules on 58 (56-61); stylet = 22 p. (21-24). the lip region. The esophageal glands overlap 10$ paratypes: L = 0.53 mm (0.46-0.60); the intestine slightly less than one body width a = 29 (25-33); b = 5.2 (4.6-6.0); b' = 4.4 to about one-and-a-half body widths. Some of (3.1-5.7); c=13 (12-15); gubernaculum = the specimens are without sperm in the sperma- 7 p. (6-9); spicules = 22 ,,, (20-25); stylet = theca. A few specimens have six lateral inci- 20 p. (19-21). sures, and in two specimens inconspicuous FEMALE (holotype): L = 0.58 mm; a = 29; lateral canals were seen in the posterior part of b = 5.0; I/ = 4.4; c = 17; stylet = 21 ^ O = the body. The female tail has 21-27 annules. 10; m = 50; V = 55. Lip region not set off, Additional specimens, identified as P. vari- three annules. Stylet knobs broadly rounded, abilifi, have been collected from soil around un- sloping posteriorly. Esophageal glands overlap known plants in Mann County, northern Cali- intestine one body width. Spermatheca round fornia. with irregularly rounded sperm. Lateral canals absent. Lateral field with four incisures, incom- Pratylenchoides leiocauda sp. n. pletely areolated on tail. Tail with 24 annules, (Fig. 3) terminus rounded with conspicuous irregular MEASUREMENTS: 159 paratypes: L = 0.60 striae. mm (0,53-0.67); a = 31 (22-37); b= 4.8 (3.6- MALE (allotype): L = 0.53 mm; a = 29; 5.6); b' = 3.8 (2.9-4.1); c = 19 (17-22); V = b = 5.4; IY = 4.5; c = 13; c' = 2.7; stylet = 20 59 (55-62); stylet = 20 p, (19-21). p.; gubernaculum = 7 p.; spicules = 22 ^,. Lip 116 paratypes: L = 0.57 mm (0.47-0.72); region narrower, higher than holotype with a = 30 (28-33); b = 5.5 (4.8-6.8); b'= 5.0 four annules. Esophagus and esophageal (3.8-6.0); c = 14 (12-16); stylet = 17 p. (15- glands smaller than holotype. Sperm irregu- 19); gubernaculum = 7 p, (6-8); spicules = 21 larly rounded to elongate or spindle shaped. /*( 18-23). HOLOTYPE: Female collected by S. A. Sher, FEMALE (holotype): L = 0.54 mm; a = 31; 27 January 1962. U.C.R. Nematode Collection, b = 4.6; I/ = 3.9; c = 20; V = 57; stylet = 20 Riverside, California. p.. Lip region flattened anteriorly, three an- ALLOTYPE: Male, same data as holotype. nules. Stylet knobs broadly rounded, sloping PARATYPES: 545 ?, 336 £, 4 juveniles same slightly posteriorly. Esophageal glands over- data as holotype distributed as follows: 5 5 $, lapping intestine one and a third times the 2 S, Department of Nematology, University of body width. Spermatheca round with irregu- California, Davis; 399 9, 28$ $, 4 juveniles, larly rounded sperm. Lateral canals absent. Department of Nematology, University of Cali- Lateral field with six incisures to four incisures fornia, Riverside; 499, 266, USDA Nema- in posterior part of body. Tail with 19 annules, tode Collection, Nematology Investigations, without striations around terminus. Beltsville, Maryland; and 699, 16 Planten- MALE (allotype): L = 0.62 mm; a = 32; b = ziektenkundige Dienst, Wageningen, The Neth- 6.2; b' = 5.4; c = 17; stylet = 19 p.; gubernac- erlands. ulum = 8 p.; spicules = 22 p.. Lip region nar- TYPE HABITAT AND LOCALITY: Soil around rower and higher than holotype, hemispherical unknown grass and weeds Twin Peaks, San with four annules. Esophagus and esophageal Francisco, California. glands not as well developed as holotype, esoph- DIAGNOSIS: P. variabilis can be distinguished ageal nuclei not visible. Sperm in posterior part from the closely related species P. crenicauda of testis elongated, spindle-shaped. by fewer annules on the female tail, usually HOLOTYPE: Female collected by S. A. Sher, longer dorsal esophageal gland overlapping the 23 October 1963, catalog number 11, U.C.R. intestine and smaller body size. Nematode Collection, Riverside, California.

Figure 2. Pratylenchoides variabilis sp. 11. A. Female, anterior region. B. Female, stylet. C. Male, anterior region. D. Female, face view. E. Male, face view. F, H. Female, posterior region. G. Male, posterior region. I. Female, tail terminus. J. Juvenile, tail terminus.

I'/A

0.02mm H

ALLOTYPE: Male, same data as holotype, FEMALE (holotype): L = 0.88 mm; a = 30; catalog number 12. b = 5.8; b' = 3.9; c = 17; V = 56; stylet = 23 PARATYPES: 45 9 5 , 29 $ $ , 6 juveniles dis- p.. Lip region flattened anteriorly, four annules. tributed as follows: 699,255, Department of Stylet knobs broad, flattened anteriorly. Esoph- Nematology, University of California, Davis; ageal glands conspicuous, almost filling body 2799, 195 $, 6 juveniles, Department of cavity with the posterior glands granular in Nematology, University of California, River- texture, overlapping intestine two body widths. side; 399, 4$ $, USDA Nematode Collec- Spermatheca round with round sperm. Lateral tion, Nematode Investigations, Beltsville, Mary- canals present. Lateral field with four incisures, land; 399, 255, Nematology Department, incompletely areolated on tail. Tail with 24 Rothamsted Experimental Station, Ilarpenden, annules, coarse striations around terminus. England; and 699,255, Labatoire des Nem- MALE (allotype): L = 0.90 mm; a = 30; b = atodes, Aiitibes, France. 6.0; b' = 4.9; c = 14; stylet = 21 p.; gubernac- TYPE HABITAT AND LOCALITY: Soil around ulum = 7 p.; spicules = 26 p.. Lip region nar- unknown grass and weeds, St. Honorat Island, rower and higher, basal plate extending further Antibes, France. into the body than in holotype. Esophagus and DIAGNOSIS: Pratylenchoides Isiocauda can bs esophageal glands not as well-developed as in distinguished from the closely related P. lati- holotype, esophageal nuclei not visible. Caudal cauda by the usual absence of striations around alae narrow. the female tail terminus, spindle-shaped sperm HOLOTYPE: Female collected by S. A. Sher, in the posterior part of the testis, smaller body 12 October 1963, catalog number 13, U.C.R. size, usually shorter stylet, and absence of lat- Nematode Collection, Riverside, California. eral canals. ALLOTYPE: Male, same data as holotype, The female lip region has three or four an- catalog number 14. nules and the stylet knobs vary from broadly PARATYPES: 11999, 9955, 9 juveniles, rounded to broadly rounded and sloping pos- same data as holotype distributed as follows: teriorly. Ventral lobe of the esophageal gland 499, 555, Department of Nematology, Uni- short or elongated (Fig. 3C) and the esopha- versity of California, Davis; 102 9 9 , 84 5 5 , 9 geal glands overlap intestine one to two times juveniles, Department of Nematology, Univer- the body width in the female. The lateral field sity of California, Riverside; 499, 455, usually has six incisures but some specimens USDA Nematode Collection, Nematology In- have four. The female tail has 16—21 annules, vestigations, Beltsville, Maryland; 399,455, and some specimens have one to three striations Nematology Department, Rothamsted Experi- around the terminus (Fig. 3 E-F). The guber- mental Station, Harpenden, England; 399, naculum sometimes has the distal portion bent 455, Plantenziektenkundige Dienst, Wagenin- (Fig. 3G). gen, The Netherlands; and 699,255, Laba- Pratylenchoides ritteri sp. n. toire des Nematodes, Antibes, France. (Fig. 4) TYPE HABITAT AND LOCALITY: Soil around unknown grass and weeds, Cape Antibes, France. MEASUREMENTS: 149 paratypes: L = 0.78 DIAGNOSIS : Pratylenchoides ritteri can be dis- mm (0.65-0.93); a = 29 (25-31); b = 5.6 tinguished from the closely related species P. (4.8-6.7); I/= 4.0 (3.1-5.5); c = 16 (13-17); laticauda and P. variabilis by the larger esopha- V = 57 (54-61); stylet = 23 P. (21-24). 105 paratypes: L = 0.71 mm (0.61-0.90); geal glands, and the longer overlap of the in- a = 31 (28-35); b = 7.1 (5.4-8.6); b'= 5.7 testine and the usually more flattened anterior (4.8-6.2); c = 14 (12-15); stylet = 20 p. (18- surface of the female stylet knobs. 21); gubernaculum = 7 p. (6-9); spicules = 26 The female lip region has three or four an- p. (23-28). nules; stylet knobs are broadly rounded to flat-

Figure 3. Pratylenchoides lewcauda sp. n. A. Female, anterior region. B. Female, anterior ovary in region of spermatheca. C. Female, esophageal glands. D-F. Female, posterior regions. G. Male, guber- naculuin. H. Male, posterior region. I. Male, anterior region.

C.E-G.I-K 0.01 mm D,H

Copyright © 2011, The Helminthological Society of Washington OF WASHINGTON, VOLUME 37, NUMBER 2, JULY 1970 163 tened anteriorly, and slightly sloping posteri- 6 January 1963, catalog number 15, U.C.R. orly. The female esophageal glands overlap the Nematode Collection, Riverside, California. intestine two- to three-and-a-half times the ALLOTYPE: Male, same data as holotype, body width, the male esophageal glands over- catalog number 14. lap the intestine about one body width (0.8— PARATYPES: 26 9 9 , 66 $ $ , 8 juveniles, same 1.2). The lateral field usually has four incisures, data as holotype distributed as follows: 1 9 9 , a few specimens have six incisures. The female 6$ $, 1 juvenile, Department of Nematology, tail has 21-28 annules. The sperm in the pos- University of California, Davis; 219 9, 48$ $, terior portion of the testis is irregularly rounded 5 juveniles, Department of Nematology, River- to angular in shape. side, California; 299, 3$ $, 2 juveniles, Additional specimens collected by the author USDA Nematode Collection, Nematology In- and identified as P. ritteri are from the follow- vestigations, Beltsville, Maryland; 19, 6$ $, ing habitats and localities in southern France: Nematology Department, Rothamsted Experi- unknown grass and weed soil, Digne, and mental Station, Harpenden, England; and 1 9, sandy soil around pine trees, Juan-Les-Pins. 3$ $, Plantenziektenkundige Dienst, Wagenin- gen, The Netherlands. Pratylenchoides bacilisemenus sp. n. TYPE HABITAT AND LOCALITY: Soil around (Fig. 5) unknown grass, Twin Peaks, San Francisco, California. MEASUREMENTS: 119 paratypes: L = 0.66 mm (0.60-0.74); a = 30 (26-34); b = 4.7 (4.3- DIAGNOSIS: P. bacilisemenus can be distinguished from the closely related species P. rit- 5.1); b' = 3.7 (3.5-4.1); c = 16 (15-18); V = teri and P. variabilis by the rod-shaped sperm 58 (55-61); stylet = 22 ^ (21-23). found in the testis and Spermatheca. It can be 11 £ paratypes: L = 0.62 mm (0.55-0.67); further distinguished from P. ritteri by the a = 30 (26-33); b = 5.5 (5.1-6.1); b'= 4.8 rounder lip region shape and the usually smaller (4.3-5.1); c = 16 (14-19); stylet = 21 ^ (20- body size, and from P. variabilis by the longer 22); gubernaculum = 7 //, (6-8); spicules = 25 overlap of the esophageal glands. /* (22-27). The paratypes have three or four annules on FEMALE (holotype): L = 0.66 mm; a — 27; the lip region. The female esophageal glands b = 4.5; b' = 3.7; c = 15; V = 57; stylet = 22 overlap the intestine one-and-a-third to two /A. Lip region slightly rounded, three annules. times the body width. Some of the females Stylet knobs rounded, sloping posteriorly. have inconspicuous spermatheca without sperm. Esophageal glands enlarged, overlapping in- The female tail has 18 to 23 annules. testine one-and-a-half times the body width. Additional specimens of P. bacilisemenus Spermatheca round with rod-like sperm. Lat- have been collected by the author near the eral canals present. Lateral field with four in- type locality (Twin Peaks, San Francisco), on cisures. Tail with 21 annules, tapering to three separate occasions, from soil around wild striated terminus. strawberry and grass. MALE (allotype): L = 0.57 mm; a = 31; b = Pratylenchoides specimens, probably repre- 5.0; b' = 4.7; c = 15; stylet = 21 p.; gubernac- senting additional speciation, have been exam- ulum = 6 ft,; spicules = 26 p.. Lip region slightly ined from the following locations: Toronto, narrower than holotype, hemispherical, four an- South Dakota; Newport, Oregon; Tok and nules. Esophagus and esophageal glands not as Delta, Alaska; Sevier County, Utah; Hammond, well-developed as in female, overlapping in- Louisiana; Taos, New Mexico; Santa Barbara, testine less than one body width, nuclei incon- Fillmore, Victorville, Desert Springs, Pear Blos- spicuous. som, Orange County and San Diego County in HOLOTYPE: Female, collected by S. A. Sher, southern California; Mikve and Givat Rambam,

Figure 4. Pratylenchoides ritteri sp. n. A. Female. B. Male. C. Female, stylet region. D. Female, face view. E. Female, surface at center of body. F. Female, posterior region. G. Male, stylet region. H. Male, face view. I. Female, surface view in region of deirid. J. Female, tail terminus. K. Juvenile, tail terminus.

0.02mm

Israel; East Taieri, New Zealand; and Omase, areas and is not known to have any important, Nara Prefecture, Japan. These are not de- widely distributed plant pathogenic species, scribed in this paper because of insufficient or although the type species, P. crenicauda, has poorly preserved specimens, or both. been identified from widely separated areas of the world. Discussion Acknowledgments After an examination of the type specimens, the author agrees with Braun and Loof (1966) A. H. Bell and L. Wang assisted in the prep- that Zygotylenchus toamasinae (de Guiran, aration of nematode slides, measurements and 1964), Zygotylenchus guevarai (Tobar, 1963) illustrations. and Tylenchorhynchiis gadcai (Arias, Jimenez Literature Cited and Lopez, 1965) do not belong in ths genus Pratylenchoides. Arias-Delgado, M., F. Jimenez-Millan, and J. The genus Pratylenchoides is most closely M. Lopez-Pedregal. 1965. Tres nuevas es- related to the genus Radopholus, and the spe- pecies de nematoclos posibles fitoparasitos en suelos espanoles. Publ. Inst. Biol. Apl. (Bar- cies of Pratylenchoides with elongated esopha- celona) 38: 47-58. geal glands overlapping the intestine (P. ritteri, Bor, N. A., and J. J. s'Jacob. 1966. Pratylen- P. leiocauda and P. bacilisemenus) are especially choides maritimus, a new nematode species similar in appearance to species of Radopholus. from the Boschplaat, Terschelling. Ncmatolo- P. bacilisemenus also has rod-like sperm, which gica 12: 462-466. occur in most species of Radopholus. The mi- Braun, A. L., and P. A. A. Loof. 1966. Pra- gratory endoparasitic root habitat of Pratylen- tylenchoides laticauda n. sp., a new endo- choides is the same as that of species of Radoph- parasitic phytonematode. Neth. T- Pi- Pathol. olus, although observations have not been 72: 241-245. Goodcy, T. 1932, The genus Anguillulina Gerv. made on all the species and one, P. laticauda, and v. Ben. 1859, vel Tylenchus Bastian, has been shown to be a pathogen of plants 1865. J. Helminthol. 10: 75-180. (Hijink and van Rossen, 1968). . 1940. On Anguillulina multicinita Pratylenchoides differs from the genus Ra- (Cobb) and other species of Anguillulina as- dopholus in having deirids; less reduction of sociated with the roots of plants. J. Helmin- the stylet and esophagus in the male; usually thol. 18: 21-38. broadly rounded stylet knobs, sloping distally; de Guiran, G. 1964. Mesotylus: Nouveau genre a more variable type of overlapping esophageal de Pratylenchinae (Nematoda: Tylenchoidea). glands with at least one esophageal nucleus Nematologica 9: 567-575. , and M. R. Siddiqi. 1967. Characters above the esophageal intestinal valve; guber- differentiating the genera Zygotylenchus Sid- naculum not protruding from the cloaca; and diqi, 1963 (Syn. Mesotylus de Guiran, 1964) usually a lower position of the phasmicls on the and Pratylenchoides Winslow, 1958 (Nema- tail. toda: Pratylenchinae). Nematologica 13: 235- The genus Pratylenchoides appears to be 240. almost worldwide in distribution with no known Hijink, M. J., and H. van Rossen. 1968. area of large speciation, whereas the genus Inoculaties met Pratylenchoides laticauda Radopholus is apparently native to Australia Braun and Loof bij Monarda hi/bride "Croft- (Sher, 1968) where it has many species. In way Pink" en Mentha piperita L. Meded. Rijksfak. Landbouw-wetensch. (Gent) 33: addition, the one widely distributed species of 729-737. Radopholus, the very important plant pest R. Jairajpuri, M. S. 1964. On Pratylenchoides similis (Cobb, 1893), is usually found in the crenicauda Winslow, 1953 (Nematoda: Praty- warmer areas of the world. The genus Praty- lenchidae) from Srinagar (Kashmir), India. lenchoides is in the cooler, more temperate Curr. Sci. 33: 339.

Figure. 5. Pratylenchoides bacilisemenus sp. n. A. Female, anterior region. B. Female, central portion of ovaries. C-D. Female, posterior regions. E. Juvenile, tail terminus. F. Male, posterior region. G. Male, anterior region.

Sher, S. A. 1968. Revision of the genus Ra- with additional data on Pratylenchoides gue- dopholus Thorne, 1949 (Nematoda: Tylen- varai Tobar Jimenez, 1963 (Syn. Zygotylen- choidea). Proc. Helm. Soc. Wash. 35: 219- chus browni Siddiqi, 1963 and Mesotylus 237. gallicus de Guiran, 1964). Nematologica 11: Siddiqi, M. R. 1963. On the classification of 432-440. Tobar Jimenez, A. 1963. Pratylenchoides gue- the Pratylenchiclae (Thorne, 1949) nov. grad. varai n. sp., nuevo nematode tylenchido, rela- (Nematoda: Tylenchida) with a description cionado con el cipres (Cupressus sempervirem of Zygoti/lenchus broivni nov. gen. et nov. sp. L.). Rev. Iber. Parasitology 22: 27-36. Z. Parasitenk. 23: 390-396. Winslow, R. D. 1958. The taxonomic position Tarjan, A. C., and B. Weischer. 1965. Ob- of Anguillulina obtusa Goodey, 1932 and servations on some Pratylenchinae (Nemata), 1940. Nematologica 3: 136-139.

Development, Migration, and Survival on Pasture of Gastrointestinal Nematodes of Cattle: Summer Contamination

AARON GOLDBERG Beltsville Parasitological Laboratory, Animal Disease and Parasite Research Division, Agricultural Research Service, USDA, Beltsville, Maryland 20705

ABSTRACT: Development, migration, and survival of infective larvae were studied following deposition of fecal pats containing eggs of Ostertagia ostertagi, Cooperia punctata or Oesophagostomum radiatum on pasture at Beltsville, Maryland, at the beginning of summer (24 June 1968). Initial and peak recovery of larvae from the pats occurred 0.5-1, and 1-2 weeks later, respectively. Final recovery of larvae from them occurred 8 weeks after deposition for O. radiatum and 9.5 weeks for C. punctata and O. ostertagi. Initial recovery of larvae from the herbage occurred at 2 weeks for all species; peak recovery, at 2 (O. radiatum), 3 (C. punctata), or 4 (O. ostertagi) weeks; and final recovery, at 8 (O. radiatum), 20.6 (C. punctata), or 24 (O. ostertagi) weeks. The percentage of development for O. ostertagi was consider- ably higher than that of the other species, but its migration onto the herbage was not as great as it was in previous trials begun in May. The high temperatures and high evaporation rates of summer were probably responsible for the death of most larvae (97% of the peak recovery) by 1 September 1968. Eighty- five to 88% of the larvae recovered, per unit weight of herbage, was within 13 cm of the pats. This find- ing is an important reason for not overstocking pastures because, under normal stocking, cattle tend to avoid the forage around feces.

The most recent reviews of some of the fac- for infective larvae. The trial begun in summer tors affecting development and survival of the involved only Haemonchus contortus. The free-living stages of parasites of ruminants on present study concerns development and sur- pasture are given by Levine (1963), Crofton vival of Ostertagia ostertagi, Cooperia punctata, (1963), and Kates (1965). and Oesophagostomum radiatum in summer. Development and survival of gastrointestinal Development of these parasites in late spring, nematode parasites of cattle on pasture at Belts- ville, Maryland, were reported by Goldberg and survival in summer, had been studied in (1968). In that investigation, egg-containing the trial begun 2 June 1961. In other trials fecal pats were deposited on clean pasture at begun in summer (Goldberg and Rubin, 1956), various times of the year, and at intervals, the spring, and autumn (Goldberg and Lucker, pats and surrounding herbage were examined 1959 and 1963), calves were used to test the