Plectus thornei
Rühm, 1956
Photo Gallery- Konza Prairie

Dimensions: Female- L =  0.87-1.065 mm, a = 22.59-25.35, b = 4.07-4.53, c = 8.28-14.44, V = 48.08-50, Stoma = 0.32mm
Male- L = 0.825-0.93mm, a = 23.57-26.57, b = 4.13-4.22, c = 11.46-12.65, Stoma = .032mm, Spicules 0.032-0.036mm, Gubernaculum 0.009-0.011mm.
Female:  Cuticle thick and clearly annulated.  Longitudinal stripes appear with fine knot-like thickenings (it appears, from Rühm's illustrations that four longitudinal alae are present in each wing area).  Scattered setae on body of adults and larvae.  Six distinct lips, each exhibits two granular structures.  Four thin cephalic setae, two ventral submedian and two dorsal submedian.  Amphids clearly visible.  Prorhabdions strongly cuticularized, slightly curved and non-articulate.  Esophagus begins on posterior portion of prostom.  Meso-metastom funnel-shaped, uniformly cuticularized.  Esophagus, at first, slender, then widens regularly to isthmus; posterior bulb oval.  Triradiate denticulated valve of posterior bulb well developed.  Nerve ring at junction of corpus and isthmus.  Vulva equatorial.  Gonads paired, short with swollen club-like ovaries.  Tail slender, terminates with a spinneret.
(Descriptions and measurements after Rühm 1956.)
Male:  Similar to female.  Two preanal supplementary tubuli consistently present.  Two postanal papillae.  Spicules paired, gubernaculum well-developed.  Tail terminates with spinneret.
Habitat:  Spruce mold in larval galleries of Ips typographus.
Locality- Regensburg, Germany
This species may be distinguished from other species of Plectus by the four longitudinal alae in each wing area.  Rühm felt that this species should be placed close to Anaplectus granulosus (used as Plectus granulosus in Ruhm's paper). Rühm's illustrations, however, indicate that this is a species of Plectus and not Anaplectus.
(Description- Maggenti, 1961)