OF WASHINGTON, VOLUME 40, NUMBER 1, JANUARY 1973 123 Speer, C. A., and D. M. Hammond. 1970. tured bovine cells. J. Protozool. 18 (Suppl.): Development of Eimeria larimerensis from the 11. Uinta ground squirrel in cell cultures. Ztschr. Vetterling, J. M., P. A. Madden, and N. S. Parasitenk. 35: 105-118. Dittemore. 1971. Scanning electron mi- , L. R. Davis, and D. M. Hammond. croscopy of poultry coccidia after in vitro 1971. Cinemicrographic observations on the excystation and penetration of cultured cells. development of Eimeria larimerensis in cul- Ztschr. Parasitenk. 37: 136-147. A Synopsis of the Genera and Species in the Tylenchorhynchinae (Tylenchoidea, Nematoda)1 A. C. TARJAN2 ABSTRACT: The genera Uliginotylenchus Siddiqi, 1971, Quinisulcius Siddiqi, 1971, Merlinius Siddiqi, 1970, Ttjlenchorhynchus Cobb, 1913, Tetylenchus Filipjev, 1936, Nagelus Thome and Malek, 1968, and Geocenamus Thorne and Malek, 1968 are discussed. Keys and diagnostic data are presented. The following new combinations are made: Tetylenchus aduncus (de Guiran, 1967), Merlinius al- boranensis (Tobar-Jimenez, 1970), Geocenamus arcticus (Mulvey, 1969), Merlinius brachycephalus (Litvinova, 1946), Merlinius gaudialis (Izatullaeva, 1967), Geocenamus longus (Wu, 1969), Merlinius parobscurus ( Mulvey, 1969), Merlinius polonicus (Szczygiel, 1970), Merlinius sobolevi (Mukhina, 1970), and Merlinius tatrensis (Sabova, 1967). Tylenchorhynchus galeatus Litvinova, 1946 is with- drawn from the genus Merlinius. The following synonymies are made: Merlinius berberidis (Sethi and Swarup, 1968) is synonymized to M. hexagrammus (Sturhan, 1966); Ttjlenchorhynchus chonai Sethi and Swarup, 1968 is synonymized to T. triglyphus Seinhorst, 1963; Quinisulcius nilgiriensis (Seshadri et al., 1967) is synonymized to Q. acti (Hopper, 1959); and Tylenchorhynchus tener Erzhanova, 1964 is regarded a synonym of T. clarus Allen, 1955. The following are regarded in spe- cies inquirendae: TetylencJius dimidius Kirjanova, 1951; Aphelenchus dubius Steiner, 1914; and Fratylenchoides gadeai Arias-D, Jimenez-M. and Lopez-P., 1965. Since my first compendium on Ttjlencho- proposed the new subfamily Merliniinae to ac- rhynchus (Tarjan, 1964), there have been a commodate Merlinius and formed two new number of new species proposed, two addi- genera within the Tylenchorhynchinae made tional keys prepared (Baqri and Jairajpuri, up of certain species formerly in Tylenchorhyn- 1970 and de Guiran, 1967), and new genera chus. The first of these is Uliginotylenchus proposed which are closely related to Tylen- with three incisures comprising an areolated chorhynchus (Siddiqi, 1970, 1971; Thorne and lateral field, female tail clavate to cylindroid Malek, 1968). In his first paper Siddiqi and with over 25 annules, and proximal end (1970) erected the new subfamily Tetylen- of gubernaculum bent dorsally. The second chinae to include the genus Tetylenchus and genus, Quinisulcius, has a nonareolated lateral proposed a new genus Merlinius to accommo- field with five incisures, distal flanges of date species of Tylenchorhynchus having six spicula are small-sized, and the proximal end incisures in the lateral field, a small trough- shaped nonprotrusible gubernaculum, and stout of gubernaculum directed dorsally. spicules with distal ends notched and without It is the object of the present study to large ventral flanges. Siddiqi's second paper evaluate the position of Tijlenchorhynchus and closely related genera, to determine member- 1 Florida Agricultural Experiment Stations Journal Series ship in such genera, and to present keys and a No. 4450. -Professor (Nematologist), University of Florida, IF AS, table of diagnostic data on species. The work Agricultural Research and Education Center, Lake Alfred, Florida 33850. presented was compiled only from publica- Copyright © 2011, The Helminthological Society of Washington 124 PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY tions and not from actual examination of present status of Trichotylenchus Whitehead, specimens. 1959 and Telotylenchus Siddiqi, 1960. Jairajpuri (1969) stated that Trichotylenchus differed Subfamily considerations from Telotylenchus only by a slightly narrower The Tylenchorhynchinae are, and have been, head, delicate spear, and three-incisured lateral a relatively homogenous group readily recog- field. In a later paper (1971), he presented nized by their cuticular markings, labial struc- a more detailed account corroborating and ture, stylet characteristics, esophagus structure, illustrating these differences. Jairajpuri re- sexual system arrangement, and tail shape. I garded Telotylenchus a junior synonym of see no practical value in assigning such closely Trichotylenchus. Seinhorst (1971) did not related genera as Tetylenchus, Tylenchorhyn- refer to the Jairajpuri references and regarded chus, and Merlinius to three different sub- the two genera as distinct, separated by stylet families, e.g., Tetylenchinae, Tylenchorhyn- appearance, shape of female tail, lateral field, chinae, and Merliniinae, respectively (Siddiqi, and shape of gubernaculum. He included 1971). Accordingly, I prefer to follow the ar- Trichotylenchus falciformis Whitehead, 1959; rangement suggested by Golden (1971) in T. rectangularis Netscher and Germani, 1969; recognizing one subfamily, the Tylenchorhyn- T. rhopalocercus (Seinhorst, 1963); T. palustris chinae, in which the new genus Merlinius (Merny and Germani, 1968); T. uliginosus (Siddiqi, 1970) can also be conveniently (Siddiqi, 1970); and T. papyrus (Siddiqi, accommodated. 1970) in the genus. He justified inclusion of some of these species, which in their original Previous departures descriptions do not all have the same type of basal portion of the esophagus, by suggesting In addition to the accurate list given by that the original authors misinterpreted the Baker (1962), Table 2 cites departures from true structure of the esophagus. Seinhorst's Tylenchorhynchus as given by various authors placement of these species thus results in a during the past two decades. genus in which: (a) two species (falciformis and rectangularis) have pronounced esopha- The genus Uliginotylenchus Siddiqi, 1971 geal overlaps, while four species do not; (b) This genus was characterized essentially as five species have delicate or slender stylets having an areolated lateral field with three in- while one (palustris) does not; (c) five species cisures, moderately sclerotized cephalic frame- have three-incisured lateral fields while one work, labial region not offset, spermatheca (rectangularis) has four incisures; and (d) offset, spicules with large-sized distal flanges, four species have somewhat clavate tails while gubernaculum with proximal portion directed two species (rectangularis and palustris) have dorsally, female tail with 25 or more annules cylindrical tails. Then, too, no mention is and broadly rounded, and occurring in wet made of Whitehead's (1959) original char- soil. The characters above appear to be valid acterization of Trichotylenchus as having a except for the cephalic framework which is head divided into four lobes and a distinctly invariably lightly, not moderately, sclerotized forked stylet. Because of these discrepancies for the five species included and for the offset and because I feel that the distinct and pro- nature of the spermatheca which is unknown nounced overlap of the esophagus on the in- for four of the five species. Of the species testine is of cardinal importance in identifying included, U. bifasciatus (Andrassy, 1961) ap- species of Trichotylenchus, I regard Siddiqi's pears to deviate most from the generic criteria (1971) assignment of species as the most in that: (a) its lip region is weakly offset, not logical. continuous; (b) its males do not show spicules It would be convenient to include the four with large-sized distal flanges; and (c) its remaining three-incisured "Tylenchorhynchus" type locality was in garden soil, not marshy or species in Uliginotylenchus, i.e., T. chonai, T. wet soil. divittatus, T. sculptus, and T. triglyphus. This Uliginotylenchus cannot be evaluated with- is not feasible principally because: (a) none out referring to the current controversy on the of the species have areolated lateral fields, Copyright © 2011, The Helminthological Society of Washington OF WASHINGTON, VOLUME 40, NUMBER 1, JANUARY 1973 125 broadly rounded female tails with more than The generic diagnosis given by Golden (1971), 25 annules, or occur in wet soils, and (b) most patterned after previous diagnoses, is more of these species do not have gubernacula with inclusive. However, one of the principal char- proximal parts directed dorsally, spicules with acters of the genus, "cephalic framework large-sized distal flange, or lightly sclerotized present," becomes suspect when diagnostic cephalic frameworks. data on Tylenchorhynchus species is inspected (Table 1). Under the heading of "framework Key to Females of Uliginotylenchus* sclerotization" it can be seen that among 45 1. Tail with 24-35 annules, lip region with species, 13 have inconspicuous cephalic frame- 4-5 annules, tail terminus smooth ____ works, 6 have frameworks which were not ____ palustris (Merny and Germani, 1968) mentioned or depicted, while 15 have lightly Siddiqi, 1971 sclerotized frameworks. Tail with 42-56 annules, lip region with Siddiqi (1970) transferred Tylenchorynchus 5—8 annules, tail terminus annulated 2 galeatus Litvinova, 1946 to Merlinius. He later 2. T/ABW = 2.6-2.7, lip region 5-6 an- agreed (in litt.) that the species best be taken