Montana Field Guide

Genus Austrotyla: Posterior colpocoxites of male gonopds more complex than simply consisting of long, thin structure partially sheathed at base by sternal process, posterior colpocoxites of male gonopods lacking articulated basal flagellum, anterior gonopods flattened (more or less plate-like), usually larger than posterior gonopod colpocoxites, with lateral sternal processes at least partially fused to lateral regions of anterior gonopods, posterior gonopods with telopodites, anterior gonopods not fused and with sternum entire, anterior gonopods larger than posterior gonopod colpocoxites (Shear 1976).

[From Loomis and Schmitt 1971] Austrotyla montani: Length of largest male 8 mm, largest female 11 mm. Eye group subtriangular, ocelli 18-20, in four series as 2, 4, 6, 8, or 3, 4, 5, 7, beginning nearest antenna. Fairly large and definite pronotum present above a broad, subbasally depressed mentum. Anterior gonopods (peltogonopods) somewhat separated, narrower, more nearly parallel-sided, with apex truncate rather than rounded. Posterior gonopods essentially as in other species. Male legs 3 and 4 with joint 4 swollen, the ventral digitate process large and nearer distal end of joint. Coxae of tenth legs each with a long subcylindrical process in front, slightly constricted near middle, projecting forward between second joints of gonopods and outer edge of peltogonopods.

Adults reported early April to late October, young reported in mid-October (Loomis and Schmitt 1971).

Closely related to Austrotyla montivaga, but with differences of the gonopods and location of lobe of fourth joint of male legs 3 and 4 (Loomis and Schmitt 1971). The male tenth coxae also with lobes, lacking in A. borealis (Shear 1976).

Found under logs and rocks in or near riparian areas, probably under a mixed deciduous and conifer tree canopy (Loomis and Schmitt 1971).