Key to the Genera of Tylenchidae

adapted from Geraert and Raski, 1987

1 a Females diovarial 2  
b Females monovarial 5  
2 a Tail short, subcylindrical, rounded; stylet very long (90-110Ám)   Macrotrophurus
b Tail elongate, attenuated; stylet < 20Ám 3  
3 a Cephalic framework sclerotized; vulva with lateral membranes; male cloaca with hypoptygma   Antarctenchus
b Cephalic framework not sclerotized; vulva withithout lateral membranes; male cloaca without hypoptygma 4  
4 a Head high, amphidial slit obvious; metacorpus posterior to middle of esophagus   Psilenchus
b Head low, amphidial slit indistinct; metacorpus anterior to middle of esophagus   Atetylenchus
5 a Stylet very long (76-104Ám)   Tylodorus
b Stylet long (38-52Ám)   Epicharinema
c Stylet moderate (22-34Ám) 6  
d Stylet short (<22Ám) 7  
6 a Cuticle with longitudinal ridges   Campbellenchus
b Cuticle without longitudinal ridges   Gracilancea
7 a Head with setae 8  
b Head without setae 9  
8 a Vulva covered by longitudinal flap; male without caudal alae; male cloaca with hypoptygma   Atylenchus
b Vulva with lateral flaps; male with caudal alae; male cloaca raised   Eutylenchus
9 a Cuticle with longitudinal ridges 10  
b Cuticle without longitudinal ridges 14  
10 a Cone about 1/3 of stylet length 11  
b Cone almost 1/2 of stylet length 13  
11 a Transverse striations not visible through longitudinal ridges   Basirienchus
b Transverse striations and longitudinal ridges form block (tessellate or areolate) pattern; lateral field with 4 lines 12  
12 a Lip region with 2-3 annules, stylet without knobs   Neothada
b Lip region with 6-7 annules, stylet without knobs   Basirienchus
13 a Vulva covered by longitudinal flap; stylet 17-19Ám   Pleurotylenchus
b Vulva with lateral flaps; stylet <15Ám   Coslenchus
14 a Cone about 1/3 of stylet length 15  
b Cone almost 1/2 of stylet length 28  
15 a Head high, with distinct lateral amphid slits 16  
b Head variously shaped, amphid slit longitudinal 19  
16 a Female body ventrally curved or spiral; female with offset spermatheca and oocytes in multiple rows   Boleodorus
b Female body straight; oocytes not in multiple rows 17  
17 a Tail bent or hook-shaped near tip   Basirienchus
b Tail more or less straight    
18 a Stylet without knobs, anterior part with wide lumen   Neopsilenchus
b Stylet with or without knobs, anterior conical with narrow lumen   Basiria
19 a Head with disc-like structure 20  
b Head with smooth contour 22  
20 a Head with small disc 21  
b Head with large dome-shaped structure   Cucullitylenchus
21 a Very slender (a=62-76); caudal alae concave posteriorly   Mitranema
b Less slender; caudal alae rounded   Filenchus
22 a Very slender (a=60-180); caudal alae lobed 23  
b Body width variable; caudal alae rounded if present 24  
23 a Head quadrangular; pore-like amphid apertures; body constricted after vulva   Ecphyadophora
b Head flattened; long amphid apertures; body not constricted after vulva   Ecphyadophoroides
24 a Cuticle deeply incised 25  
b Cuticle not deeply incised 26  
25 a Head quadrangular; body striations with zigzag pattern; male without caudal alae   Miculenchus
b Head flattened; male with caudal alae   Malenchus
26 a Very slender; indistinct striation; head very flat; long, sinuous amphid aperture   Lelenchus
b Larger body diameter; distinct striation; head quadrangular; aperture not sinuous 27  
27 a Head high with longitudinal amphid apertures lateral; clavate stylet knobs; DEGO > 1/2 stylet length behind knobs   Irantylenchus
b Head quadrangular; distinct striation; round stylet knobs; DEGO < 1/2 stylet length behind knobs   Filenchus
28 a Vulva with lateral flaps 29  
b Vulva without flaps 30  
29 a Lateral field of 2 lines; vagina thin; post-vulval sac short   Allotylenchus
b Lateral field of 3 lines; vagina thickened; post-vulval sac short   Aglenchus
c Lateral field of 4 or 6 lines; vagina not thickened; post-vulval sac long   Cephalenchus
30 a Lateral field and striations inconspicuous; caudal alae very small   Polenchus
b Lateral field and striations distinct; caudal alae distinct   Tylenchus