Helicotylenchus digonicus
Perry, 1959
Photo Gallery- Konza Prairie
Photo Gallery- Nine-mile Prairie
Photo Gallery- Haughton Crater
Species Comparisons- heads
Species Comparisons- tails
Species Comparisons- entire bodies

L = 0.7 mm; a = 26; b = 5.8;  c = 45; V = 51
Body spiral when relaxed. Lip region truncate with 4 annules. Spear 25u long with cupped knobs. Dorsal esophageal gland opening 10u-14u behind spear knobs. Spermagonia conspicuous with thick cellular walls, sperms often present during reproductive period.  Tails bluntly conoid to rounded, rarely with slight projection. Phasmids 2-8 annules anterior to anus.
     The spermagonia, so prominent in this and related species, have created considerable controversy.  Hirschman and Triantaphyllou, 1965, consider them degenerate spermathecae, and Sher, 1966, concurs with this veiwpoint.  However, the author agrees with Perry, 1959, that cells of thick walls produce sperms which fertilize eggs as they move from the ovary into the uterine tract.  True spermathecae do not have thick cellular walls and it appears highly improbable that during degeneration they should develop into such elaborate cellular structures. Helicotylenchus usually has very definite periods of reproduction which last for 4-6 weeks and only during this time are sperms observed.

Habitat:  Bluegrass lawn, Brookings, South Dakota
(Thorne and Malek, 1968 description)

DNA Sequences Obtained
Specimen: Collected:
KonzaIII FF-143 Konza Prairie, First survey