Superfamily Criconematoidea Taylor, 1936

Diagnosis- Criconematina. Small-sized (seldom over 0.8 mm), showing marked sexual dimorphism. Females and juveniles sausage- to spindle-shaped with thick cuticle and coarse retrorse annules (annules secondarily rounded in females of Hemicriconemoidinae and some Criconematinae), with or without scales, spines and other configurations; males vermiform with not so thick cuticle and annules always rounded and a degenerate oesophagus hardly showing any structure. Lateral fields with incisures in males, absent in juveniles and females. Cephalic region of juveniles and females with one or two annules, an indistinct labial disc bearing I-shaped oral aperture surrounded by six pseudolip areas, with or without submedian lobes; no sensory papillae or pits on surface; in males cephalic region usually continuous, rounded and striated, and framework not appearing in lateral view as 'spectacle mark'. Stylet well developed in juveniles (exceptionally absent in some stages) and females. Conus markedly longer than shaft, latter usually about 10-12 um long, basal knobs prominent, appearing anchor-shaped. Orifice of dorsal oesophageal gland 3-6 um behind stylet base; stylet absent in males. Juveniles and females with well-developed criconematoid oesophagi, precorpus broad, posteriorly expanded and continued into a slightly broader, very muscular, postcorpus having large, elongated rrefractive thickenings; the two parts forming a broad cylindrical muscular corpus filling the body width. Isthmus short, broad and amalgamated with a small reduced basal bulb offset from intestine and containing the three oesophageal glands. A small non-cellular cardia may be present. Excretory pore at, or behind base of oesophagus. Intestine syncytial, lacking lumen. Vulva far posterior, ovary anteriorly outstretched. Postvulval uterine sac absent. Male develops by metamorphosis within a sausage-shaped juvenile. Testis degenerate in adult; gonoduct packed with numerous, very small, round sperms produced at one stage of development. Spicules elongate-setose, almost straight to arcuate, proximally cephalated and distally pointed; gubernaculum simple, fixed. Male tail short; bursa low, adanal, subterminal or terminal, occasionally absent. Juveniles lack a body sheath. Ectoparasites of roots, males and some juveniles incapable of tissue feeding.
-Siddiqi, 2000
Type and only family: Criconematidae Taylor, 1936
Criconematid Project.....(Suborder) Criconematina.....(Family/Subfamily) Criconematoidae
 
Emended Key to Subfamilies of Criconematidae - based on Siddiqi, 2000

1
Female with a cuticular body sheath of round annules; juveniles with scales or spines usually arranged irregularly or in alternating rows
female
juvenile scales
 
.......................................................................Hemicriconemoidinae
 
Female without a cuticular body sheath; scales or spines in juveniles, if present, almost always arranged in longitudinal rows
 
female
juvenile
 
 
..............................................................................................................2

 

 
2
Females and juveniles with annules ornamented with scales, spines or other appendages (except females of Criconema)
 
 
.................................................................................Criconematinae
 
Female and juveniles with smooth or crenate annules lacking scales, spines or other appendages
 
 
................................................................................Macroposthoniinae