BULLETIN DE L'INSTlTUT ROYAL DES SCIENCES NATURELLES DE BELGIQCE, BIOLOGIE, 64 : 17-42, 1994 BULLETIN VAN HET KONINKLIJK BELGISCH INSTlTUUT VOOR NATUURWETENSCHAPPEN, BlOLOGIE, 64: 17-42, 1994

Scanning electron microscopy observations on Telotylenchinae SIDDIQI, 1960 (Nemata : Belonolaimidae). 3. The genus Tylenchorhynchus COBB, 1913.

by Pierre BAUJARD, Danamou MOUNPORT & Bernard MARTINY

Abstract CHENG, 1988; RASHlD & HEYNs, 1990; ZEIDAN & Geraert,1990; LAL & HINEs, 1991; GOMEZ BARCINA et Ten species of the genus Tylenchorhynchus were studied under SEM, al., 1992) reveal great differences, particularly in the Observations showed the great heterogeneity of the genus according head face view, between species of Tylenchorhynchus. to the head pattern and confirmed the absence of validity of some characters at the taxonomic level (number of incisures in the lateral More recently, MOUNPORT et al., (1993) compared the field, presence vs absence of longitudinal ridges, presence vs absence ultrastructure of the cuticle of nine species of the genus of notch on the bursa), Four to five different head patterns can be concluding that it might be composed of several genera recognized, corresponding to the cuticle ultrastructure patterns pre­ which must be redefined on the basis of light and scan­ viously defined. Bitylenchus is considered as a junior synonym of Tylcnchorhvnchus, and B. pratensis and B, serranus are transferred to ning electron microscopy. the genus 'lylenchorhynchus. This work presents the results of observations on ten Keywords: Nemata, Belonolaimidae, Tylenchorhvnchus, morpho­ species belonging to the genus Tylenchorhynchus, some logy, scanning electron microscopy. of them previously described and/or transferred in gene­ ra presently considered as synonyms of Tylenchorhyn­ chus (see FORTUNER & Luc, 1987): Bitylenchus Resume FILIP'EV, 1934, Telotylenchus SIDDIQI, 1960, Dolichor­ hynchus MULK & JAIRAJPURI, 1974, Neodolichorhyn­ Dix espcces du genre Tylenchorhynchus ont ete ctudiccs en microsco­ eh us JAIRAJPURI & HUNT, 1984. Nine of these species pie electronique a balayage. Les observations reverent une here­ were studied by MOUNPORT et al. (1993). rogcneite considerable des structures cephaliques cxternes et confir­ ment labsence de validite de certains caractercs morphologiques au niveau taxonomique (nombre dincisures dans les champs lateraux, presence vs absence de cretes longitudinales, presence vs absence dechancrure sur la bursa). Les structures cephaliques externes Material and methods peuvent etre groupees en quatre acinq types diffcrcnts qui correspon­ dent a ceux definis precedemrnent sur I'ultrastructure de la cuticule. SPECIES STUDIED Bitylcnchus est considere comme un synonyme mineur du genre Tvlenchorhynchus, et les especes B. pratensis et H. scrranus sont Tylenchorhynchus annulatus (CASSIDY, 1930) GOLDE:", 1971. transferees au genre Ty lenchorhynchus. Mots-cle : Nemata, Belonolaimidae, Tylenchorhynchus, morphologie, syn. Tylenchorhvnchus martini FIELDING, 1956. microscopie electronique abalayage. Tylenchorhynchus germanii FORTUNER & Luc, 1987. syn. Dolichorhynchus (Dolichorhynchus) elegans GER­ MANI & Luc, 1984. Tylenchorhynchus elegans (GERMAN! & Luc, 1984) FOR­ Introduction TUNER & Luc, 1987 (nee T. elegans SIDDlQI, 1961). Tylenchorhynchus gladiolatus FORTUNER & AMOUGOU, 1973. syn. Dolichorhynchus (Neodolichorhynchus) gladiolatus Recent studies on the taxonomy of the genus Tylenchor­ (FORTUNER & AMOUGOU, 1973) MULK & SIDDIQI, hynchus (SIDDIQI, 1986, FORTUNER & Luc, 1987) are 1982. principally based on morphological and biometrical Neodolichorhynchus gladiolatus (FORTUNER & characters observed in light microscopy. Of the 130 spe­ A\1oCGou, 1973) JAIRAJPCRI & HC'\'T, 1984. cies listed in the genus Tylenchorhynchus (FORTUNER & Tvlenchorhynchus indicus (SIDDIQI, 1960) FORTU:"ER & Lt.c, Luc, 1987), little is known on their morphology as seen 1987. syn. Telotvlenchus indicus SIDDIQI, 1960. under scanning electron microscopy (SEM). Previous Tylenchorhynchus mashhoodi SIDDIQI & BASIR, 1959. studies (SHER & BELL, 1975; LEWIS & GOLDEN, 1981; Tylenchorhynchus microphasmis LOOF, 1960. VOVLAS & CHAM, 1981; JAIRAJPURI & HUNT, 1984; syn. Dolichorhynchus (Neodolichorhynchus) microphas­ SAtJER, 1985; LOPEZ & SALAZAR, 1987; VOVLAS & mis (Loo!', 1960) MULK & SIDDIQI, 1982. 18 P. BAUJARD, D. MOUNPORT & B. MARTINY

Fig. 1 - Tylenchorhynchus mashhoodi females (A-D, C-J) and males (E-F. J-L). A and B. C and D, E and F : respecrively in face and lareral view of {he same specimen; C: vuIvar region; H-L : rails; A-F : scale bar = J /-Lm;C-L : scale bar = JO /-Lm. Scanning electron microscopy observations on Telotylenchinae 19 ... • Neodo/ichorhynchus microphasmis (LOOF, 1960) JAI­ Table 1 : RAJPURI & HUNT, 1984. Laboratory culture conditions and number of specimens Ty/enchorhynchus su/catus DE GUIRAN, 1967. observed under SEM. syn. Do/ichorhynchus (Neodolichorhynchus) su/catus (de Guiran, 1967) MULK & SIDDIQI, 1982. Neodo/ichorhynchus su/catus (DE GUIRAN, 1967) JAI­ Species Soil Extraction Number RAJPURI & Hunt, 1984. temperature date of specimens Ty/enchorhynchus ventra/is (LOOF, 1963) FORTUNER & Luc, and observed 1987. moisture (females-males) syn. Te/oty/enchus ventra/is LooF, 1963. Ty/enchorhynchus vu/garis UPADHYAY, SWARUP & SETHI, T. annulatus 1972. "KK" population 34°-10 28.02.1986 30 syn. Bity/enchus vu/garis (UPADHYAY, SWARUP & SETHI, % 1972) SIDDIQI, 1986. 11.05.1987 42 Ty/enchorhynchus phaseo/i SETHI & SWARUP, 1968. 21.01.1991 30 syn Do/ichorhynchus (Dolichorhynchus) phaseoli (SETHI "CSS" population 34°-10 % 05.03.1986 30 & SWARUP, 1968) MULK & JAIRAJPURI, 1974. 13.12.1986 30 = Ty/enchorhynchus sp. in MOUNPORT et a/., 1993. 23.01.1991 30 T. germanii 34°-10 % 20.11.1986 22-30 ORIGIN OF SPECIMENS 14.02.1991 30-30 T. gladiolatus 30°-10 % 01.12.1986 29-21 T. annulatus: two populations ongmating from 25.05.1987 26-23 Richard-Toll, Senegal in 1982 ("CSS" population) and 27.03.1990 30-30 from samples taken along the road Kaffrine-Koungheul, T. indicus 34°-10 % 08.12.1986 28-30 Senegal ("KK" population) in 1984 and paratypes of T. T. mashhoodi 34°-10 % 19.03.1991 30-30 martini originating from the Riverside Nematode Col­ T. sulcatus 34°-10 % 24.11.1986 20-20 lection, University of California, U.S.A. 26.03.1991 30-30 T. germanii : topotypes from Patar, Senegal in 1984. 24.01.1992 30-30 T. gladiolatus : Nebe, Senegal in 1986. T. ventralis 34°-10 % 12.12.1986 15- 4 T. indicus : Thienaba, Senegal in 1988. 12.03.1990 30-30 T. mashhoodi : Tara, Niger in 1990. T. vulgaris 30°-10 % 26.05.1988 30 T. microphasmis: The Netherlands (sent by Dr. EC. 24.01.1992 30 ZOON). 13.07.1992 30 T. sulcatus : N'Dindy, Senegal in 1982. T. phaseoli 36°-10 % 25.04.1988 30 T. ventralis : Louga, Senegal in 1982. 10.06.1988 30 T. vulgaris : Agadez region, Niger in 1987. 08.03.1991 30 T. phaseoli : Aogadut region, Niger in 1987.

PREPARATION OF SPECIMENS FOR SEM STUDIES Results Except for the paratypes of T. martini and specimens of T. microphasmis, the other species were cultured at HEAD constant soit temperature and soit moisture (Table 1) on Sorghum vulgare L. in the laboratory since the sampling T. mashhoodi (Fig. 1, A-F), the two Senegalese popula­ date, extracted by elutriation (SEINHORST, 1962), killed tions of T. annulatus and T. martini paratypes (Fig. 2, A­ by gentle heating (600 C) during 30 seconds and then I) : head square like in lateral view; cephalic constric­ processed without fixation for SEM as described by tion absent; in front view, head rounded to laterally BAUJARD and PARIS ELLE (1987). Specimens of T. micro­ elongated with six more or less pronounced longitudinal phasmis were obtained in fixative and processed by the depressions, two dorso-ventral and four submedial; same technique. Paratypes of T. martini and sorne speci­ three to four cephalic armuli present; oral aperture a mens of T. indicus and T. ventralis were processed for dorso-ventral slit surrounded by a small rim itself sur­ SEM and photographed by Dr. BELL as described by rounded by six labial sensilla; labial disc not prominent, SHER & BELL (1975). squarish to four lobed, demarcated by an incisure inter­ In order to evaluate a possible variability in the morpho­ rupted by the amphid apertures; first cephalic annulus logical characters, several specimens extracted at diffe­ not differentiated into lip sectors; amphid aperture late­ rent times were studied for each species from laboratory rally situated at the edge of the labial disc, circular cultures (Table 1). (occurrence: 27 % in the "CSS" population and 17 % in the "KK" population) to ovoid, the longer axis being dorso-ventrally orientated (occurrence: 73 % in the 20 P. BAUJARD, D. MOUNPORT & B. MARTINY

w•

••' 1 Fig. 2 - Tylenchorhynchus annulatus,females; A-F: "CSS" populO/ion, C-.!, L : paralypes ofT. marlini; K, M : "KK" popu­ lalion. A-I : heads (A and B, C and D, E and F, C and H' respeClively laieraI and in fron! l'iew oflhe same specimen); .!-K: vu/val' region (Ihe while arl'Ow shows Ihe direuion of Ihe anleriol' region); L-M : Iails; A-I : scale har = 1 }.Lm; f. Scanning electron microscopy observations on TeJotylenchinae 21

Fig. 3 - Tylenchorhynchus annulatus. fema/es of the "CSS" population. N and O. Q and p. Rand S: respective/y vu/var region and vu/va of the same specimen (the white arrow shows the direction ofthe anterior region): T-W .' tai/s: N. Q, R-W: sca/e bar = 10 /Lm: O. P, S: sca/e bar = J jLI1J. 22 P. BAUJARD, D. MOUNPORT & B. MARTINY

"CSS" population and 83 % in the "KK" population). that of T microsphasmis except i) two dorso-ventral No sexual dimorphism in head morphology. longitudinal depressions never transformed into inci­ sures, ii) absence of longitudinal slits below the amphid T gladiolatus (Fig. 4) and T vulgaris (Fig. 6) : head apertures, iii) presence of a small cuticular rim around rounded in lateral view; cephalic constriction present; in the amphid apertures, forming the two laterallip sectors front view, head rounded to laterally elongated with or (Fig. 14: C-D), iv) rounded appearance of the labial without two dorso-ventral longitudinal depressions disc demarcated by a circular groove (Fig. 14 : B-D). giving a bilobed appearance when present and two late­ raI longitudinal slits below the amphid aperture; six to T germanii (Fig. 16: A-K), T sulcatus (Figs. 19: A-D; ten cephalic annuli present; oral aperture circular sur­ 20 : O-R) : head morphology similar to that of T micro­ rounded by a small rim itself surrounded by 6 labial phasmis except for i) small circular labial disc, ii) com­ sensilla; labial disc non prominent, four lobed, demar­ plete separation of the submedial lip sectors from the cated by an incisure interrupted by the amphid aper­ labial disc and iii) discret dorso-ventral deformation of tures; in sorne specimens, this incisure is also inter­ the male heads. rupted ventrally and/or dorsally; sorne supplementary incisures present on the lobes of the labial disc giving LONGITUDINAL ORNAMENTATIONS OUTSIDE THE LATER­ the appearance of differentiated submedial lip sectors; AL FIELD first cephalic annulus not differentiated into lip sectors; amphid aperture circular, with a contour more or less No longitudinal omamentations outside the lateral fields convoluted, laterally situated at the edge of the labial are observed in T annulatus (Figs. 2 : L-M; 3 : N, Q, T­ disc, prolonged by a longitudinal incisure until the W) , T indicus (Fig. 9), T mashhoodi (Fig. l : G-L) and cephalic constriction. T ventralis (Figs. la: I-N; 11: V-V). In T vulgaris, longitudinal incisures are observed only in the anterior T indicus (Fig. 8), T ventralis (Figs. 10: A-H, 11 : 0­ region of the body, between the head and the beginning T) : head rounded in lateral view; cephalic constriction of the lateral fields (Figs. 6, 7). In T. germanii, T gladio­ present; in front view, head rounded with two slight latus, T microphasmis, T sulcatus and T phaseoli, lon­ dorso-ventral longitudinal depressions giving a bilobed gitudinal ridges are observed all along the body; these appearance and with two to seven short longitudinal ridges are contiguous in T gladiolatus and well sepa­ slits below the amphids up to the fifth cephalic annulus; rated in the four other species (Figs. 4, 5, 12-20). the transverse annulation disappears between these lon­ gitudinal slits; seven to eight cephalic annuli present; LATERAL FIELD oral aperture dorso-ventrally elongated, without rim, surrounded by six labial sensilla; labial disc slightly Three bands are observed in the lateral field of all these demarcated, not prominent, squarish; first cephalic species except in T phaseoli where the lateral field is annulus without lateral sectors and with submedial sec­ constituted by a unique ridge not demarcated by tors partially fused to the labial disc; arnphid aperture incisures (Fig. 15: J-L, 0-T); four incisures delimit circular, laterally situated at the edge of the labial disco the three contiguous bands in T annulatus (Figs. 2: Sexual dimorphism present in head morphology : male L-M; 3: N, T-W), T gladiolatus (Fig.5), T indicus heads with the four submedial lip sectors prominent (Fig. 9), T mashhoodi (Fig. 1 : H-L), T ventralis (Figs. separated or not from the labial disc by an incisure (Figs la: I-N; 11 : V-V), T vulgaris (Fig. 7) and the ridges in 8: C, E, G; Il: 0-T); head face asymmetrical, the T germanii (Fig. 17 : M, R, V), T microphasmis (Figs. ventral side being wider than the dorsal one (Figs 8 : E­ 12: E, G; 13: S-T), T sulcatus (Figs. 19: E-H; 20: G; Il : Q, P-T). S-T). The central band/ridge ends on tail at or immediatly Tylenchorhynchus microphasmis (Figs. 12: A-D; 13: posterior to phasmid level in all the species (Figs. l : H­ O-R) : head morphology similar to that observed in T L, 2 : L-M; 3 : T-W; 5 : J-M; 7: J-K; 9 : K-L; 10: M-N; indicus and T ventralis except i) two dorso-ventral lon­ 13: K-M; 17: S-V; 19: K-N) exceptin Tphaseoli (Fig. gitudinal depressions more pronounced (Fig. 12 : B, D) 15: 0-T) where the unique ridge of the lateral field and sometimes transformed into a deep incisure (Fig. reaches the tail end. 12: C) and ii) submedial lip sectors more prominent Areolations in the lateral fields: they are few, erratic (Fig. 12: B-D) with a partial (Fig. 12: B) to complete and present only on the two outer bands in T annulatus incisure (Fig. 12 : C-D) separating them from the labial (Figs. 2: L-M; 3: N, T-W) and T mashhoodi (Fig. 1 : disco Sexual dimorphism as in T indicus and T ventralis H-L); in T gladiolatus (Fig. 5), T indicus (Fig. 9), T with sometimes a complete disorganization of the labial ventralis (Figs. la: 1-N; Il : V-V), T vulgaris (Fig. 7), disc and first cephalic annulus (Fig. 13 : Q). T germanii (Fig. 17 : M, R, V), T. microphasmis (Figs. 12: E, G; 13: S-T) and T sulcatus (Figs. 19: E-H; 20 : T phaseoli (Fig. 14 : A-D) : head morphology similar to S-T), the three bands are regularly areolated, the areola- Scanning electron microscopy observations on Telotylenchinae 23

Fig. 4 - Tylenchorhynchus gladiolatus,females (A-D) and males (E-F) heads. A, B : infranl views; C and D, E and F : respec­ tively lateral and in front view ofthe sarne specimen .. scale bar = 1 /-Lm. 24 P. BAUJARD, D. MOUNPORT & B. MARTINY

,-

Fig. 5 - TyJenchorhynchus gladiolatus,females (G-L) and males (M-N). G-I : vuIvar regiol1 (the white arrow shows the direc­ tiol1 ofanterior region); J-N: tails; scale bar = 10 p..m. Scanning electron microscopy observations on Telotylenchinae 25

". tions being two times more spaced than the transverse white on SEM photographs are observed inside the body annulation. vulvar slit (Figs. 1 : G; 2: K; 3: N-S; 5 : G-I; 7 : F-I; 9: H-J; 10: I-L; 12: F, H-I; 15: H-K; 17: N-Q; 19: VULVA AND VENTRAL ORNAMENTATIONS IN THE VULVAR G). Lateral vulvar membranes (flaps) are absent in ail REGION the species; in the species with ridges, the transverse vulvar opening is always lined by two slightly inden­ In aIl the species studied, the vulva appeared as a trans­ tated longitudinal ridges : T gladiolatus (Fig. 5 : G-I), T verse slit with two slightly prominent anterior and micl'Ophasmis (Figs. 12: F, H-I; 13: J), T. phaseoli (Fig. posterior lips; in some specimens of ail these species, 15: J-K), T germanii (Fig. 17 : N-Q), T sulcalus (Fig. one or two non prominent lips (epiptygma) appearing 19: G, 1).

Fig. 6 - Tylenchorhynchus vulgaris,jemales heads. A. B, C: infront view; D: laIerai view; D and E : respectively lateral and infront view ofrhe same specimen; scale bar = J fJ-m. 26 P. BAUJARD, D. MOUNPORT & B. MARTINY

Fig. 7 - Tylenchorhynchus vulgaris, fernales. F-J: vu Ivar region (Ihe while arrow shows the direction of anterior region); J-L : lails; scale har = JO /-Lm. Scanning electron microscopy observations on Telotylenchinae 27

G

Fig. 8 - Tylenchorhynchus indicus,jemale (A, D, F) and male (B, C. E, G) heads. A, B: laierai view; C-G : in Fonl view; scelie bar = J j..tm.

Ventral omamentations in the vulvar region are present vulva, the same situation is present (Fig. 17: O-Q) or in ail the species studied except in T. phaseoli where the not, the ventral ridge ending just in front of the vulva ventral lidge reaches the vulva without any modifica­ (Fig. 17 : N, P); alterations of the transverse body annu­ tion. These ornamentations showed great variation in i) lation occured sometimes just behind the vulva on a their occurrence in each species (absent or present in the short length (Fig. 17 : N-P). same species or al ways present), ii) their pattern (varia­ T. g/adio/atus : anomalies of the transversal body annu­ tion of body width, longitudinal incisure or disorganiza­ lation are always present but only behind the vulva (Fig. tion of the transverse annulation, iii) their localization 5 : O-l). (in front and/or behind vulva) : T. indicu.s : omamentations can be absent (Fig.9 : J) or T. annu/atus : ornamentations can be absent (Fig. 3 : R) present as alterations of the transverse body annulation or present as a longitudinal incisure in front and behind in front and behind the vulva (Fig.9 : H-I). vulva (Fig. 2 : J) or alteration of the transverse body T. mashhoodi : a longitudinal incisure is present in front annulation only behind (Fig. 2: K) or behind and in and behind the vulva (Fig. 1 : 0). front of the vulva (Fig. 3 : N, Q). T. microphasmis : ventral ridge subdivided into two sub­ T. germanii : the ventral ridge subdivided in front of the ventral ridges in front and behind the vulva, the two vUlva into two subventral ridges, the two previous sub­ previous subventral ridges being interrupted (Figs. 12: ventral ridges being interrupted (Fig. 17 : N-Q); behind H-I; 13 : J); no other omamentations occured ventrally. 28 P. BAUJARD, D. MOUNPORT & B. MARTINY

Fig. 9 - Tylenchorhynchus indicus,jemales (H-L) and males (M). H-f : vu/var regiol1, K-M : lails; scale bar = /0 I-tm. Scanning electron microscopy observations on Telotylenchinae 29

T. sulcatus: ventral ridge subdivided in front of the peculiar characteristics except in T. mashhoodi where a vulva into two subventral ridges, the two previous sub­ short distal process is present at the distal end giving a ventral ridges being interrupted; behind the vulva, the bifid appeareance to spicule tip (Fig. 1 : K-L) and in ventral ridge ends just in front of the vulva (Fig. 19: J); T. gladiolatus where a minute notch is present ventrally alterations of the transverse body annulation occurred at the distal end of the spicules (Fig. 5 : M-N). both in front and behind the vulva (Fig. 19: 1) or only Gubernaculum only seen in bisexual species with pro­ behind the vulva (Fig. 19 : J). truding spicules. Protrusion of gubernaculum variable in T. ventralis : in lateral view the body shows a widening T. mashhoodi (six males with protruded gubernaculum in front of the vulva and a narrowing behind the vulva in ten males observed) and constant in T. gladiolatus, (Fig. 10: I-J); in ventral view, two groups (one in front T. microphasmis, T. germanii and T.sulcatus. Guberna­ and one behind the vulva) of ridges are longitudinally culum in T. mashhoodi, T. microphasmis, T. germanii, placed (Fig. 10 : K-L); they correspond probably to the T. sulcatus with three knobs, one distal and central, ftat­ underlying musculature of the vagina (dilatatores vagi­ tened, supporting the dorsal shaft of the spicule and two nae); alterations of the transverse body annulation subdistal and lateral, rounded, inserted in a longitudinal occurs on a short length just behind the vulva. groove present on the dorsal side of the velum (Figs. T. vulgaris: alterations of the transverse body annula­ 16: L; 17: W, Z, AA; 20: S, U, V); in T. gladiolatus, tion are always present (Fig. 7 : F-I), variations occuring only the distal knob, triangular in shape, protruding both in length (from 5 to 15 ~m long) and in position (in from the cloaca is observable. front and/or behind the vulva). MISCELLANEOUS OBSERVATIONS FEMALE TAIL In T. phaseoli, excretory pore in variable position, on or Tail conoid to cylindrical with a rounded terminus in T. along the ventral ridge (Fig. 14 : E-G); anus surrounded mashhoodi (Fig. 1 : H-I), T. annulatus (Figs. 2 : L-M; by a circle of cuticular blocks (Fig. 15 : M-N). 3 : T-W), T. gladiolatus (Fig. 5 : J-L) or with a rounded to acute terminus in T. vulgaris (Fig. 7 : J-L); tail coni­ cal with a rounded terminus in T. indicus (Fig. 9 : K-L), Discussion T. ventralis (Fig. 10: M-N), and T. phaseoli (Fig. 15: 0-T); with an acute terminus in T. microphasmis (Fig. The head patterns observed in this study can be grouped 13 : K-L), T. germanii (Fig. 17: S-V) and T. sulcatus into five types (Table 2) : (Fig. 19 : K-N). Table 2 : PHASMID Characterizations of the five groups of species accord­ ing to longitudinal body ornamentations and head fea­ Phasmids punctiform in T. mashhoodi (Fig. 1 : H-I), T. tures (+ = present; - = absent, * = ventral and dorsal annulatus (Figs. 2 : L-M; 3 : U-W), T. gladiolatus (Fig. depressions strong; ? = undetermined). 5 : J-L), T. indicus (Fig. 9: K-L), T. ventralis (Fig. 10: M), T. microphasmis (Fig. 13 : K), T. germanii (Fig. 17 : Species groups Characters S, U, V) and T. sulcatus (Fig. 19: M-N). Phasmids 2 3 4 5 wider in T. vulgaris (Fig. 7 : J-K) and variable in dia­ meter in T. phaseoli, from punctiform (Fig. 15 : S-T) to longitudinal ornamentations -/+ -/+ -/+ -/+ -/+ wide (Fig. 15 : O-P) with intermediate widths (Fig. 15 : on the cuticle outside the Q-R). lateral fields head profil - squarrish + MALE COPULATORY APPARATUS - rounded + + + + head - continuous + Bursa peloderan without distal notch in T. mashhoodi - set off + + + + (Fig. 1 : J-L), T. gladiolatus (Fig. 5 : M-N), T. indicus head annuli number <5 >5 >5 >5 >5 (Fig. 9 : M), T. ventralis (Fig. II : U-V), T. microphas­ longitudinal depressions 6 4 6* 6* 6* mis (Fig. 13: M), T. sulcatus (Fig. 20: T- V). Notchs on head present or absent in the first extracted population of T. lateral incisures on head + germanii, variable in depth when present (Fig. 18: W­ labial disc - rectangular + + + AB); in the second extracted population, notch always - rounded + + absent. lip sectors - submedial -/+ -/+ + + Spicules never protruding on SEM observed specimens - lateral + of T. indicus and T. ventralis; for the other bisexual spe­ head sexual dimorphism + + ? cies, spicules protruding with large velum and without 30 P. BAUJARD, D. MOUNPORT & B. MARTINY

Fig. 10 - TyJenchorhynchus ventralis. females. A-H : heads (A, C: respectively lateral and in fronl \'iew of the same speci­ men); I-L : vulvar region (the white arrow shows the direction of anterial' region); M-N : tails; A-H : scale bar = 1 p.m; /-N : scole bar = JO p.m. Scanning electron microscopy observations on Telotylenchinae 31

Type 1 : head profile squarish; head continuous; five or here for T. germanii and T. sulcatus and also in other less cephalic annuli; six longitudinal depressions slight­ species of the genus : T. aff. ohregonus (Fig. 9, A-B in Iy pronounced; no lateral incisure; labial disc rectangu­ ZEIDAN & GERAERT, 1990). lar with submedial lip sectors completely fused; no lateral lip sectors; no sexual dimorphism in head mor­ Type 5 : head profile rounded; head set off; more than phology. This type is observed here for T. annulatus (see five cephalic annuli; six longitudinal depressions pre­ also LOPEz & SALAZAR, 1987) and T. mashhoodi and sent, the four submedial slightly pronounced and the also in other species of the genus : T. cylindricus, type dorsal and ventral ones weil pronounced up to a com­ species of the genus (Fig. 5, A in SHER & BELL, 1975), plete incisure; lateral incisures absent; labial disc T. lamelliferus (Fig. 3, C, D in SHER & BELL, 1975), T. rounded with submedial lip sectors weil demarcated aduncus (Fig. 1, A-D in VOY LAS & CHAM, 1981), T. cla­ completely or incompletely separated from the labial rus (Figs. 1, 2, p. 7 in SAUER, 1985), Tylenchorhynchus disc by a incisure; lateral lip sectors present; sexual sp. (Fig. l, 2, p. 8 in SAuER,1985) T. crassicaudatus dimorphism not determined (males absent). This type is (Fig. 7, A in ZEIDAN & Geraert, 1990), T. clathrocutis observed here for T. phaseoli and also in other species (Figs. 9,10 in LEWIS & GOLDEN, 1981). and genera: Tylenchorhynchus sp. (Fig. 1-4, p. 9 in SAUER, 1985), T. velatus (Fig. 5-6, p. 9 in SAUER, 1985), Type 2 : head profile rounded; head set off; more than Tylenchorhynchus maximus (Fig. 537 in DE GRISSE, five cephalic annuli; four longitudinal depressions 1977; Fig. 36-38 in GOMEZ BARCINA et al., 1992), Bity­ slightly pronounced; lateral incisures below the amphid lenchus pratensis (Fig. 27 in GOMEZ BARCINA et al., aperture present; labial dise rectangular with submedial 1992). The population of T. phaseoli studied by SHER & lip sectors more or less demarcated by an incomplete BELL (1975; Fig. 3, A, B) shows submedial lip sectors incisure; no lateral lip sectors; no sexual dimorphism in slightly less developed than in the Niger population and head morphology. This type is observed here for T. gla­ longitudinal body ridges fused at the anterior end just diolatus and T. vulgaris and also in other species and below the head vs separated in the Niger population. genera : T. goffarti (Fig. 5, B in SHER & BELL, 1975), T. tohari (Fig. 5-6, p. 8 in SAUER, 1985), T. hrevilineatus Several species of the genus Bitylenchus redefined by (Fig. 3, A-D in ZEIDAN & GERAERT, 1990; Fig. 6, B in GOMEZ BARCINA et al. (1992) show great differences in RASHID & HEYNs, 1990), Bitylenchus serranus (Figs. 9­ head morphology. The emendation of the genus states Il in GOMEZ BARCINA et al., 1992). "cephalic region ... with lateral longitudinal indenta­ tions on annuli behind amphidial apertures ... and ante­ Type 3 : head profile rounded; head set off; more than riormost lip annulus 6-sectored". At least three species five cephalic annuli; six longitudinal depressions pre­ did not share the first character, B. maximus (ALLEN, sent, the four submedial slightly pronounced and the 1955) SIDDIQI, 1986, B. pratensis GOMEZ BARCINA et dorsal and ventral ones weil pronounced up to a com­ al., 1992, B. velatus (SAUER & ANNELS, 1981) GOMEZ plete incisure; lateral incisures absent; labial disc rectan­ BARCINA et al., 1992; whereas B. serranus GOMEZ BAR­ gular with submedial lip sectors not demareated in CINA et al., 1992 did not possess the second eharacter. females, more or less demarcated by an incomplete Bitylenchus FILIP'EV, 1934 is then considered a junior incisure in males; no lateral lip sectors; sexual dimor­ synonym of Tylenchorhynchus; B. pratensis and B. ser­ phism present in head morphology with a dorso-ventral ranus are transferred to the genus Tylenchorhynchus as deformation of the head and submedial lip sectors being T. pratensis (GOMEZ BARCINA et al., 1992) n. comb. and more individualised. This type is observed here for T. T. serranus (GOMEZ BARCINA et al., 1992) n. comb. indicus, T. microphasmis and T. ventralis and also in other species of the genus: T. acutus (FigA, A, B in This study supports the statements of FORTUNER & Luc SHER & BELL, 1975), T. parvus (Fig. 2 in LAL & HINES, (1987) regarding the validity of sorne characters cur­ 1991), T. prophasmis (Fig. l, A-B in JAIRAJPURI & rently used for identification purposes in the taxonomy HUNT, 1984), and T. teeni (Fig. 5, A-D in ZEIDAN & of the genus: T. phaseoli showed only two lines (one GERAERT,1990). ridge) in the lateral field, a unique feature in the Teloty­ lenchinae confirmed by TEM (MouNPoRT et al., 1993); Type 4 : head profile rounded; head set off; more than longitudinal ridges are present in several species (T. gla­ five cephalie annuli; six longitudinal depressions pre­ diolatus, T. germanii, T. microphasmis, T. sulcatus, T. sent, the four submedial slightly pronounced and the phaseoli, T. lamelliferus) which showed strong differen­ dorsal and ventral ones weIl pronounced up to a com­ ces in head morphology; lateral membranes at vulva did plete incisure; lateral incisures absent; labial disc not exist, being confused under light microscopy with rounded with submedial lip sectors demarcated and subventral longitudinal ridges; presence of notches on completely separated; no lateral lip sectors; sexual caudal alae appeared to be a variable character at the dimorphism present in head morphology with a dorso­ species level (T. germanii). ventral deformation of the head. This type is observed The SEM observations on the head morphology in the 32 P. BAUJARD, D. MOUNPORT & B. MARTINY

Fig. 11 - Tylenchorhynchus ventralis, males. O-T: heads (O. Q: respecrively lareral and infi"onr view orthe sarne specimen); V·V: tails; O-T. scale har = 1 pm; V-V: scale har = 10 j.Lm. Scanning electron microscopy observations on Telotylenchinae 33

Fig. 12 - Tylenchorhynchus microphasmis, females. A-D' heads (A, B : respectively lateral and in frol1l view of the same specimen); E-G : excrelOry pore: A-D : scale har = / Jl-m; E-G : scale bal' = /0 Jl-m. 34 P. BAUJARD, D. MOUNPORT & B. MART1NY

Fig. 13 - Tylenchorhynchus microphasmis, temales (i-M) and males (O-T). i: vu Ivar re~ion (the white arrow shows the direction or allterior region); K-M : tails; O-Q . heads; S-T. lateral field; O-R : scale bar = J /Lm; i-M. S-T. scale bar = la /Lm Scanning electron microscopy observations on Telotylenchinae 3S

Fig. 14 - Tylenchorhynchus phaseoli, females. A-D : heads (A, B: respective/y latera/ and in Font view of the same speci­ men), E-G : excretory pore: A-D : scelle bar = 1 !Lm; E-G : scale bar = 10 !Lm.

genus Tylenchorhynchus revealed the great heteroge­ MANI for the photographs of T. annulalus, T. marlini, T. neity of this group; it is now possible to recognize at gladiolatus, T. indicus and T. ventratis. least four different types (five if the complete separation of the submedial lip sectors from the labial disc is con­ sidered as a stable characteristic) which might need a generic status; the grouping of the stlldied species References according to the head morphology correspond to that proposed by MouNPoRT et al. (1993) on the basis of the BAUJARD, P. & PAR1SELLE, A. (1987). Fabrication de microta­ ultrastructure of the cuticle. More than 130 species are mis et préparation des nématOdes pour l'observation au described in the genlls Tylenchorhynchus as defined by microscope électronique à balayage. Revue de Némat%gie, FORTUNER & Luc (1987); the SEM studies of the mor­ 10: 477-481. phological characteristics and the reexamination of the DE GRISSE, A. T. (1977). De Ultrastruktuur van hel zenuw­ species under light microscopy constitllte a preliminary stelsel in de kop van 22 soorten plantenparasitaire Nemato­ den, behorende tot 19 genera (Nematoda : Tylenchida). Rijks­ before any taxonomical changes in the genus could be universiteit Gent, Belgium, 420 p. proposed. FORTuNER, R. & Luc, M. (1987). A reappraisal of Tylenchina (Nemata). 6. The family Belonolaimidae Whitehead, 1960. Revue de Némat%gie. JO: 183-202. Acknowledgements GOMEZ BARC1NA, A., SIDDIQl, M.R. & CASTlLLO, P. (1992). The genus Bily/enchus Filip'ev, 1934 (Nematoda: Tylenchi­ The authors thank Dr. F. C. ZOON for sending specimens da) with description of two new species From Spain. Journa/ of T. microphasmis and Drs. A. H. BELL and G. GER- ofthe He/minthological Society ofWashington, 59: 96-110. 36 P. BAUJARD, D. MOUNPORT & B. MARTINY

t JAIRAJPURI, M. S. & HUNT, D. J. (1984). The taxonomy of VOVLAS, N. & CHAM, S. (1981). Scanning electron micro­ Tylenchorhynchinae (Nematoda: Tylenchida) with longitu­ scope observations on the morphology of Tylenchorhynchus dinallines and ridges. Systematic Parasitology, 6 : 261-268. aduncus. Nematologia mediterranea, 9: 91-97. LAL, A. & HINES, S. (1991). Redescription of Tylenchorhyn­ VOVLAS, N. & CHENG, H. (1988). Morpho-anatomy of Tylen­ chus (Bitylenchus) parvus Allen, 1955 with SEM observa­ chorhynchus leviterminalis from the People's Republic of tions. Nematologia mediterranea, 19: 241-245. China. Nematologia mediterranea. 16: 149-152. LEWIS, S. A. & GOLDEN, A. M. (1981). Description of Trili­ ZEIDAN, A. B. & GERAERT, E. (1990). The genus Tylencho­ neellus clathrocutis n. g., n. sp. (Ty1enchorhynchinae : Tylen­ rhynchus in Sudan (Nematoda: Tylenchida). Mededelingen chida Thome, 1949) with a key to species and observations on van de Fakulteit Landbouwwetenschappen Universiteit Gent. Tvlenchorhynchus sensu stricto. Journal of Nematology. 13 : 55: 761-778. 135-141. LOPEZ, R. & SALAZAR, L. (1987). Nematodos asociados al Pierre BAUJARD arros (Oriza sativa L.) en Costa Rica. III. Microscopi electro­ üRSTüM nica de rastreo de Meloidogyne y Tylenchorhynchus annula­ Laboratoire de Nématologie tus. Turrialha, 37 : 77-83. B.P. 1386 MOUNPORT, D., BAUJARD, P. & MARTlNY, B. (1993). Cuticle Dakar, Sénégal fine structure of nine species in the genus Tylenchorhynchus Cobb, 1913 (Nemata : Be10nolaimidae). Fundamental and Present address applied Nematology, 16: 137-149. Muséum National d'Histoire Naturelle Laboratoire de Biologie Parasitaire, RASHID, F. & HEYNS, J. (1990). Tylenchorhynchus species from Namibia (Nematoda: Be10nolaimidae). Phytophylacti­ Protistologie, Helminthologie ca, 22 : 403-412. 61 rue Buffon F-75231 Paris cedex 05 SAUER. M.R. (1985). A scanning electron microscope study of plant and sail nematodes. C.S.I.R.ü. Division of Horticultural Danamou MOUNPORT Research, 64 p. Laboratoire de Biologie Animale SEINHORST, J.W. (1962). Modifications of the elutriation Faculté des Sciences method for extracting nematodes from soils. Nenw!ulogica, Dakar, Sénégal 8:117-128. SHER, S.A. & BELL, A.H. (1975). Scanning electron micro­ Bernard MARTIN Y graphs of the anterior region of sorne species of Tylenchoidea üRSTüM (Tylenchida : Nematoda). Journal ofNematology, 7 : 73-77. Laboratoire de Nématologie SIDDlQI, M.R. (1986). Tylenchida Parasites of Plants and B.P. 1386 Insects. Siough, UK, Commonw. Inst. Parasit., x + 645 p. Dakar, Sénégal Scanning electron microscopy observations on Telotylenchinae 37

Fig. 15 - Tylenchorhynchus phaseoli,females. H-L : vulvar region (the white arrow shows the direction or anterior region); M-N: anus; O-T: lails; H-L, O-T: scale bar = 10 /-Lm; M-N. scale bar = 1 /-Lm. 38 P. BAUJARD, D. MOUNPORT & B. MARTINY

"

Fig. 16 - Tylenchorhynchus germanii,Jemales (A-F) and males (G-L). A-K : heads (A-B, C-D, E-F, G-H : respeclive/y laIerai and infront view of the same specimen); L : spicules; scale bar = 1 p,m. Scanning electron microscopy observations on Telotylenchinae 39

Fig. 17 - Tylenchorhynchus germanii,females. M-R: vulvar region (the while arrow shows the direction or anterior region); S-V' lails; M-V' scale bar = JO pm. 40 P. BAUJARD, D. MOUNPORT & B. MARTINY

Fig, 18 - Tylenchorhynchus germanii, males, W-AB : lails;scale har = 10 j.Lm. Scanning electron microscopy observations on Telotylenchinae 41

Fig. 19 - Tylenchorhynchus sulcatus, females. A-D : heads (A-B, C-D : respectively, lateral and in front view of the same specimen); E-J : vulvar region (the white arrow shows the direction or anterior region); K-N : tails; A-D : scale bar = l /Lm; E-N : scale bar = JO /Lm. 42 P. BAUJARD, D. MOUNPORT & B. MARTINY ,

Fig. 20 - Tylenchorhynchus sulcatus, males. O-R: heads (O-P, Q-R: respeClively lateral and in fron! view of the same specimen). S-T: laits: O-R : scale bar = 1 /-Lm: S-V: scale bar = 10 /-Lm.