Trisaria, Shear, 2020

Shear, William A., 2020, The millipede family Striariidae Bollman, 1893: I. Introduction to the family, synonymy of Vaferaria Causey with Amplaria Chamberlin, the new subfamily Trisariinae, the new genus Trisaria, and three new species (Diplopoda, Chordeumatida, Striarioidea), Zootaxa 4758 (2), pp. 275-295 : 283-284

Trisaria , new genus

Type species: Trisaria rex Shear , new species

Etymology: The name of the genus is an anagram (rearrangement of letters) of Striaria . It should be treated as feminine in gender.

Diagnosis: Unlike species of Striaria and Amplaria , Trisaria males lack labral spines, are usually smaller (5–10 mm long), and have a crest 4 (c4) on each side of the rings posterior to the fifth suppressed, much lower than c3 and c5. The gonopods are strikingly different and significantly more complex than those of striariines, and the ninth legpair is strongly reduced, with sternum, coxae and telopodites fused or partially so. For additional characters separating the two subfamilies, see the table above.

Description: Small striariid millipedes ( Fig. 42 ; 5–10 mm long). Cranium of head with pebbled sculpture, males lack spine distolaterally on labrum. Two to four poorly formed, pigmented ocelli on each side of head. Mandibular stipes of males with low posteriorventral carina, with small carinal teeth. Collum ( Figs. 36, 37 ) apparently with 10 crests, sixth crest on each side forming expanded lateral margin of collum. Male collum ( Fig. 37 ) longer, broader than in female ( Fig. 36 ). Second ring with broadly expanded pleural margin ( Fig. 36 ). Succeeding rings with 10 crests, but posterior to ring 5, fourth crest on each side progressively suppressed, difficult to see on posteriormost rings—metazonites with strong ventrolateral marginal carinae possibly homologous to sixth crests ( Figs. 42 , 43 ). Telson ( Fig. 16 ) lacking crests, short, lobes distinctly divided. Spinnerets short, projecting anteriorly. Paraparocts (para, Fig. 16 ) densely granular, with 5 smooth depressions and three marginal setae. Male first legpair (l1, Fig. 38 , Fig. 17 ) robust, larger than second legpair, with 6 podomeres (trochanter lacking), prefemora and femora ventrally with very long, straight, blunt-tipped, 4-angled setae ( Figs. 17 ); postfemora, tibiae and tarsi with shorter somewhat flattened setae. Male second legpair coxae with vas deferens opening on the anterior side at the base of a short, heavily setose process ( Figs. 38 , 39). Male legpair 3 ( Fig. 18 ) with long, blunt extensions from the coxae, sides parallel, distally acuminate and smooth ( Figs. 19 , 40 ), without setae on posterior surface, anterior surface with scattered short appressed setae, prefemora with ectal lobes that interlock with pleural margin of corresponding pleurotergite. Male legpairs 4–7 distinctively enlarged and with flattened podomeres; lobes of coxae of legpair 7 covering bases of gonopods (cx7, Fig. 41 ). All legs with coarsely pebbled surface, scattered, flattened, scale-like setae ( Fig. 25 ), becoming more like ordinary setae distally on tarsi.

Gonopods complex. Sternum (st, Fig. 32 ) broad, well-defined, not fused to coxae. Coxae small, displaced laterally, with or without setae (cx, Fig. 33 ). Two angiocoxite processes present, positioned mesally and laterally, each with anterior (mac1, lac 1, Fig. 21 ) and posterior branches (mac2, lac2, lac3, Fig. 21 ). Median (lac2) branch of lateral angiocoxite with many thin cuticular processes arranged in comb-like array. Colpocoxite (cc, Fig. 27 ) variable in form, poorly sclerotized, with scaly cuticle. Legpair 9 ( Figs. 23 , 28 ) substantially reduced, sternum, coxae and telopodite articles fused, telopodite interlocking with process from ring 7 ( Figs. 20 , 41 ) Legpair 10 ( Fig. 24 ) with coxal glands, coxae conspicuously enlarged.

Vulvae as in Fig. 47 .

Distribution: See Map 1. Known at this time only from western Washington.

Notes: The gonopods are described in more detail in the species accounts below.

Figures

FIGURE 42. Female Trisaria olympia, lateral view.

FIGURES 5–8. Striaria columbiana. Fig. 5. Right gonopod, lateral view; aac, anterior angiocoxite, cc, posterior lobe of colpocoxite, cx, gonopod coxa, pac, posterior angiocoxite; coxa green, anterior angiocoxite red, posterior coxite blue. Fig. 6. Left gonopod, mesal view; cor, corrugations of anterior angiocoxite, fc, flagellocoxite, fp, fimbriate pad of posterior angiocoxite; flagellocoxite yellow, other labels and colors as in Fig. 5. Fig. 7. Tips of anterior angiocoxites; labels as in Fig. 6. Fig. 8. Legpair 9 of male, anterior view; cx9, coxa of leg 9, st9, sternum of legpair 9, t9, telopodite of leg 9.

FIGURES 9–14. Striaria columbiana and Amplaria imberbis. Figs. 9, 10. Striaria columbiana. Fig. 9. Left gonopod, mesal view; pcc, posterior lobe of colpocoxite; other labels as in Fig. 6. Fig. 10. Right gonopod, lateral view; labels as in Fig. 9. Figs. 11–14. Amplaria imberbis male holotype. Fig. 11. Right gonopod, lateral view; labels as in Fig. 6. Fig. 12. Angiocoxite tips of right gonopod, mesal view; labels as in Fig. 6. Fig. 13. Legpair 9 of male, anterior view; cp, coxal pore; other labels as in Fig. 8.

FIGURES 36–38. Trisaria washingtonensis. Fig. 36. Head, collum and first 2 rings of female. Fig. 37. Head and collum of male. Fig, 38. Anterior end of male, lateral view; col, collum, l1, leg 1; l2, second leg, mand, mandible, r2, pleurotergite 2. Fig. 39. Coxae 2 of male, anteriolateral view; cx2, coxa 2, cp, coxal process, gp, gonopore.

FIGURES 43–47. Trisaria olympia. Fig. 43. Anterior end of female, lateral view. Fig. 44. Legpair 1 of male, posterior view. Fig. 45. Specialized setae of femur and tibia 1 of male. Fig. 46. Specialized setae of tarsus 1 of male. Fig. 47. Genitalia of female, ventral view; lo, left operculum, lv, left valve, ro, right operculum, rv, right valve.

FIGURES 15–19. Trisaria rex. Fig. 15. Gnathochilarium of male, ventral view; isp, inner stipital palp, ll, laminae linguales, lp, lingual palp, m, promentum, osp, outer stipital palp, stg, stipes of gnathochilarium. Fig. 16. Terminal structures, ventral view; epi, epiproct, hypo, hypoproct, para, paraproct. Fig. 17. Specialized setae of legpair 1. Fig. 18. Legpair 3, anterior view; cx3, coxa, pf3, prefemur 3, s3, sternum 3. Fig. 19. Tip of coxal flask of left legpair 3, anterior view.

FIGURES 40, 41. Trisaria washingtonensis. Fig. 40. Coxae 3 of male, posterior view; cx3, coxa 3, st3, sternum of legpair 3. Fig. 41. Gonopod complex, ventral view; cx 6, coxa 6, cx7, coxa 7, gp, gonopods, t9, telopodite of leg 9.

FIGURES 20–25. Trisaria rex. Fig. 20. Gonopod complex, ventral view; art7, articulating surface of paratergite 7, cx 10, cx11, coxae of legs 10 & 11, gst, gonopod sternum, mac, median colpocoxite, lac, lateral colpocoxite, t9, telopodite of 9th leg. Fig. 21. Gonopods, anterior view; gst, gonopod sternum, lac1, lac2, first and second branches of lateral colpocoxite, mac1, mac 2, first and second branches of median colpocoxite. Fig. 22. Gonopods, posterior view; cc, colpocoxite, lac 3, third branch of lateral colpocoxite; other labels as in Fig. 21. Fig. 23. Legpair 9 of male; labels as in Fig. 13. Fig. 24. Legpair 10 of male; cx10, coxa, gp, coxal pore. Fig. 25. Part of prefemur of leg 10, showing modified setae.

FIGURES 32–35. Trisaria washingtonensis gonopods. Fig. 32. Anterior view. Fig. 33. Posterior view. Fig. 34. Lateral oblique view. Fig. 35. Ventral view; sp?, possible spiracle. All other labels as in Figs. 20 & 21.

FIGURES 26–31. Trisaria rex and Trisaria washingtonensis. Figs. 26–28. Trisaria rex. Fig 26. Anterior gonopods, anterior view; labels as in Figs. 21 and 22. Fig. 27. Gonopods, posterior view; labels as in Figs. 21 and 22. Fig. 28. Left leg 9 of male, anterior view; ap, apodeme; other labels as in Fig. 8. Figs. 29–31. Trisaria washingtonensis. Fig. 29. Left leg 9 of male, anterior view; sp, spiracle; other labels as in Fig. 8. Fig. 30. Gonopods, anterior view; gst, gonopod sternum; other labels as in Figs. 21 & 22. Fig. 31. Gonopods, posterior view; labels as in Fig. 27.