Key to adult female Tenuipalpidae from Casuarinaceae This key is based partially on that of Mesa et al. (2009). Tenuipalpus and Brevipalpus are included because these common genera are likely to be encountered occasionally from samples, and Ultratenuipalpus is included because we have collected several undescribed species from Casuarinaceae (unpublished data). This genus will be subjected to a future revision encompassing species on numerous host plants. 1. Posterior dorsal opisthosomal setae h2 long, flagellate, usually more than twice as long as distance h2-h2....... Tenuipalpus - Posterior dorsal opisthosomal setae h2 not markedly long and flagellate, usually similar in shape and size to other dorsal setae.................................................................................................... 2 2. Dorsal opisthosomal setae c2 present (Fig. 54)............................................................... 7 - Dorsal opisthosomal setae c2 absent (Fig. 95)............................................................... 3 3. Venter with well defined ventral and genital plates; 2 pairs of ps setae present............................. Brevipalpus - Venter without developed ventral plate (region membranous), genital plate or flap weakly developed, membranous; 3 pairs of ps setae present...................................................................................... 4 4. Setae on posterior margin of dorsal opisthosoma with 4–5 pairs of large leaf-like setae (e3, f2, f3, h1, h2)............................................................................... Ultratenuipalpus sensu stricto (meekeri group) - Posterior margin of opisthosoma without such setae; anterior margin of prodorsum partially or fully covering gnathosoma/inf- racapitulum; anterior margin of prodorsum with median notch forming pair of lobes (lobes may be under anterior margin of prodorsum).......................................................................................... 5 5. Opisthosomal setae e2 present; palp tarsus with 2 eupathidia and 1 solenidion (e.g. Fig. 95)............. Philippipalpus 19 - Opisthosomal setae e2 absent (Fig. 1); palp tarsus with 1 eupathidium and 1 solenidion (Figs 2 b, 107b)................. 6 6. Palp with 3 segments (Fig. 107 b); setal formula for tibiae I–IV 3-3 -2-2 (seta v′′ absent) (Fig. 114)...... Tegopalpus conicus - Palp with 4 segments (basal segment can be difficult to see) (Fig. 2 a, c); setal formula for tibiae I–IV 4-4 -3-3 (seta v′′ present) (Fig. 4)............................................................................... Chaudhripalpus 11 7. 2 pairs of ps setae present (Fig. 15 a)...................................................................... 8 - 3 pairs of ps setae present (Fig. 58 b)....................................................................... 9 8. Dorsal opisthosomal setae f2 present (Fig. 67 a); genua I–II with 2 setae (setae d and l ′′ present) (Fig. 70); anterior margin of prodorsum with 2 rounded median lobes, anterior to setae v2 (Fig. 67 a)......................... Palpipalpus hesperius - Dorsal opisthosomal setae f2 absent (Fig. 13 a); genua I–II with 1 seta (seta l or d′′ present) (Figs. 16, 28); anterior margin of prodorsum rounded, without lobes/notches (Figs 13 a, 14)........................................ Crossipalpus ... 12 9. Anterior margin of prodorsum with median notch anterior to setae v2; setae v2 inserted posterior to lobes that form notch (Figs 54, 55); coxal seta 1c usually present; trochanters I–IV usually with setal formula usually 1-1-2-1 (v ′ present)........... 10 - Anterior margin of prodorsum with median notch level with or between setae v2; setae v2 inserted either side of notch, or on lobes formed by notch (Figs. 38, 42, 48).................................................. Magdalenapalpus ... 17 10. Dorsal opisthosomal setae e2 and f2, when present, inserted in submarginal position, aligned with c2, d2 (Fig. 54).......................................................................................... Meyeraepalpus delfinadae - Dorsal opisthosomal setae e2 and f2, when present, inserted on lateral margin, aligned with setae c3, d3, e3, f3 (Fig. 75).......................................................................................... Pentamerismus ...15 11. Trochanters I–II with seta v ′ present (setal formula tr I–IV 1-1 -1-0) (Fig. 4); ventral setae ps1–2 broadly lanceolate, strongly barbed; setae ps3 setiform, thin, smooth to weakly barbed (Fig. 3); dorsal opisthosomal setae c1, d1, e1 (15–18, 13–16, 13–15 long, respectively) subequal in size to c3, d3, e3 (16–21, 16–21, 15–21 respectively) (Fig. 1)....... Chaudhripalpus creelae - Trochanters I–II with seta v ′ absent (setal formula tr I–IV 0-0-1-0) (Fig. 9); ventral setae ps1–2 narrow, setiform, barbed; setae ps3 setiform, smooth to weakly barbed (Fig. 8 b); dorsal opisthosomal setae c1, d1, e1 (13–16, 10–11, 9–10 long, respectively) slightly smaller than c3, d3, e3 (18–19, 16–19, 16–18 long, respectively) (Fig. 7).............. Chaudhripalpus costacola 12. Genua I–II with seta l′′ present and seta d absent (setal formula ge I–IV 1-1 -0-0) (Fig. 21)........................... 13 - Genua I–II with seta l′′ absent and seta d present (setal formula ge I–IV 1-1 -0-0) (Fig. 28)........................... 14 13. Tarsi I–IV with seta tc ′′ present (setal formula ta I–IV 9 (1)-9(1)-5-5) (Fig. 16); prodorsal setae v2 obviously longer than sc1 (21–26, 8–13 long, respectively); palp segments longer than wide; anterior lateral opisthosomal setae c3, d3, e 2 10 –16 long (Fig. 13 a)....................................................................... Crossipalpus muellerianae - Tarsi I–IV with seta tc ′′ absent (setal formula ta I–IV 8 (1)-8(1)-4-4) (Fig. 21); prodorsal setae v2 subequal in length to sc1 (15– 20, 17–20 long, respectively); palp segments as long as wide; anterior lateral opisthosomal setae c3, d3, e 2 19 –24 long (Fig. 19 a)............................................................................ Crossipalpus verticillatae 14. Femora and genua I–II with d seta spatulate (Fig. 28); ventral setae ag, g1 –2, ps1–2 thick, broadly lanceolate, strongly barbed (Fig. 27 a); dorsal setae broadly lanceolate (Fig. 25 a).......................................... Crossipalpus gersoni - Femora and genua I–II with d seta lanceolate (Fig. 34); ventral setae ag, g1–2, ps1–2 thin, setiform, weakly barbed (Fig. 33 a); dorsal setae narrowly lanceolate (Fig. 32 a)................................................... Crossipalpus raveni 15. Ventral setae g1–2 and ps1–2 thick, broadly lanceolate, strongly barbed; setae ag palmate, strongly barbed (Fig. 76 a); femora and genua I–II with d seta palmate (Fig. 75).............................................. Pentamerismus sititoris - Ventral setae g1–2 fine, setiform, weakly barbed; ps setae fine, setiform; ps1 thicker than ps2–3; setae ag setiform to lanceolate (Fig. 89 a); femora and genua I–II with d seta lanceolate to weakly spatulate (Fig. 90).............................. 16 16. Palp tibia with 1 seta (Fig. 88 b); ventral setae ag fine, setiform (Fig. 89 a); dorsal cuticle with broad rounded folds (Figs 88 a, 94).......................................................................... Pentamerismus hicklingorum - Palp tibia with 2 setae (Fig. 82 b); ventral setae ag lanceolate (Fig. 83); dorsal cuticle weakly reticulate (Fig. 82 a)............................................................................................. Pentamerismus wardo 17. Dorsal opisthosomal setae f2 present (Fig. 38)...................................... Magdalenapalpus strandtmanni - Dorsal opisthosomal setae f2 absent (Fig. 42).............................................................. 18 18. Distance between dorsal opisthosomal setae d1-d 1 26–30, e1- e 1 23–25; dorsal setae broadly lanceolate (Fig. 42)......................................................................................... Magdalenapalpus caperatus - Distance between dorsal opisthosomal setae d1-d 1 11–16, e1- e 1 9–13; dorsal setae narrowly lanceolate (Fig. 48 a).......................................................................................... Magdalenapalpus forsteri 19. Dorsal lateral cuticle smooth to moderately papillate; sejugal zone smooth or weakly striate (Fig. 105)................. 20 - Dorsal lateral cuticle strongly papillate; sejugal zone coarsely striate to papillate (Fig. 98 a).......................... 21 20. Dorsal lateral cuticle moderately and irregularly papillate; medial opisthonotum smooth or with few coarse striae (Fig. 105).............................................................................. Philippipalpus nigraquercus - Dorsal lateral cuticle smooth anteriorly, becoming more papillate posteriorly; medial opisthosoma with coarse striae (Fig. 103 a).............................................................................. Philippipalpus belah 21. Prodorsum coarsely rugose, forming polygons medially; opisthonotum with coarse striations (Fig. 98 a)............................................................................................... Philippipalpus flumaquercus - Prodorsum finely reticulate, forming network of small cells medially; opisthonotum rugose-papillate medially with patches of reticulation sublaterally (Fig. 95 a)...................................................... Philippipalpus agohoi

Published as part of Beard, Jennifer J., Seeman, Owen D. & Bauchan, Gary R., 2014, Tenuipalpidae (Acari: Trombidiformes) from Casuarinaceae (Fagales), pp. 1-157 in Zootaxa 3778 (1) on pages 141-142, DOI: 10.11646/zootaxa.3778.1.1, http://zenodo.org/record/251337