Allocapnia, FORBESI

Stark, Bill P. & Kondratieff, Boris C., 2012, Epiproct And Dorsal Process Structure In The Allocapnia Forbesi Frison, A. Pygmaea (Burmeister), And A. Rickeri Frison Species Groups (Plecoptera: Capniidae), And Inclusion Of A. Minima (Newport) In A New Species Group, Illiesia 8 (5), pp. 45-77 : 46-47

ALLOCAPNIA FORBESI GROUP

Ross & Ricker (1971) recognized six species ( A. curiosa Frison 1942 ; A. forbesi Frison 1929 ; A. maria Hanson 1942 ; A. minima ( Newport 1851) ; A. ozarkana Ross 1964 ; A. pechumani Ross & Ricker 1964 ); A. minima was included, perhaps tentatively, and A. frumi Kirchner 1982 was subsequently added. All species in this group, except A. minima , share a short, ornately sculpted apical segment of the upper epiproct (e.g. Figs. 2-3 , 32-33 ), and also have similar dorsal processes on abdominal terga 7 and 8 (e.g. Figs. 5-6 , 17-18 ). We have not studied details of the female genitalia, but the figures in Ross & Ricker (1971) indicate A. minima and A. maria have similar subgenital plates which differ from the other species placed in the group. On the basis of the lack of shared male characters, we are removing A. minima from this group and placing it in the Allocapnia minima group. Ross & Ricker (1971) also suggest A. illinoensis Frison 1935 , is descended from a common ancestor (#11) with members of the A. forbesi group. Presently, we have no supporting data for this hypothesis.

Ross & Ricker’s (1971) phylogenetic analysis of the A. forbesi group places it close to the A. rickeri group. This hypothesis is supported by the shared apomorphic feature of a short apical segment of the upper epiproct limb ( Figs. 2 , 98 ). The A. pygmaea group species have a longer apical segment ( Figs. 43- 44 ), but all three groups share the same wave-like spiked armature on the apical segment ( Figs. 2 , 44 , 98 ). Within the A. forbesi group, Ross & Ricker suggested A. forbesi and A. ozarkana form a sister group, and A. pechumani and A. maria form another sister group closely related to A. curiosa . Our data show A. curiosa , A. frumi , A. maria and A. pechumani share the presence of ear-like expansions on the base of the apical segment of the epiproct upper limb ( Figs. 2 , 14 , 20 , 32 ), whereas the apical segment of this structure in A. forbesi and A. ozarkana is slender and not modified with ear-like basal lobes ( Figs. 9 , 26 ). The latter two species share a deeply notched 8 th tergal process not found among other species in this group ( Figs. 11 , 28 ). These characters support the Ross & Ricker (1971) hypothesis of a sister group relationship between A. forbesi and A. ozarkana . Furthermore, we are able to place A. frumi as the probable sister species of A. curiosa , as suggested by Kirchner (1982). The basis for this assignment is the shared, thin lateral aspect of the elevated portion of the 8 th tergal process ( Figs. 4 , 15 ).

Figures

Figs. 1-6. Allocapnia curiosa, Hills Creek Falls, Pocahontas Co., West Virginia. 1. Male terminalia, dorsal. 2. Apical segment upper limb of epiproct tip, dorsal. 3. Surface detail apical segment upper limb of epiproct, dorsal. 4. Male terminalia, lateral. 5. Abdominal tergal lobes, dorsal. 6. Abdominal tergal lobes, anterodorsal.

Figs. 31-36. Allocapnia pechumani, tributary Canajoharie Creek, Montgomery Co., New York. 31. Male terminalia, dorsal. 32. Apical segment upper limb of epiproct, dorsal. 33. Surface detail apical segment upper limb of epiproct, dorsal. 34. Epiproct and tergal processes, lateral. 35. Abdominal tergal processes, dorsal. 36. Abdominal tergal processes, anterodorsal.

Figs. 13-18. Allocapnia frumi, Sugar Creek, Pocahontas Co., West Virginia. 13. Male terminalia, dorsal. 14. Apical segment upper limb of epiproct, dorsal. 15. Apical segment upper limb of epiproct and 8th tergal process, lateral. 16. Surface detail apical segment upper limb of epiproct, dorsal. 17. Abdominal tergal lobes, dorsal. 18. Abdominal tergal lobes, anterodorsal.

Figs. 97-102. Allocapnia rickeri, Turkey Creek, Scioto Co., Ohio. 97. Male terminalia, dorsal. 98. Apical segment upper limb of epiproct tip, dorsal. 99. Male terminalia, lateral. 100. 8th tergal process and epiproct tip, lateral. 101. 8th tergal process and epiproct tip, dorsal. 102. 8th tergal process and epiproct tip, anterodorsal.

Figs. 43-48. Allocapnia aurora, Horse Creek, Greene Co., Tennessee. 43. Male terminalia, dorsal. 44. Apical segment upper limb of epiproct tip, dorsal. 45. Male terminalia, lateral. 46. 8th tergal process, lateral. 47. 8th tergal process, anterodorsal. 48. 8th tergal process, dorsal.

Figs. 19-24. Allocapnia maria, Dark Horse Hollow, Wythe Co., Virginia. 19. Male terminalia, dorsal. 20. Apical segment upper limb of epiproct, dorsal. 21. Surface detail apical segment upper limb of epiproct, dorsal. 22. Epiproct apex and 8th tergal process, lateral. 23. Abdominal tergal lobes, dorsal. 24. 8th abdominal tergal lobe, anterodorsal.

Figs. 7-12. Allocapnia forbesi, tributary Big Creek, Adair Co., Kentucky. 7. Male terminalia, dorsal. 8. Epiproct and 8th tergal process, dorsal. 9. Apical segment upper limb of epiproct tip, dorsal. 10. Apical segment upper limb of epiproct and 8th tergal process, lateral. 11. Abdominal tergal lobes, lateral. 12. 8th tergal process, anterodorsal.

Figs. 25-30. Allocapnia ozarkana, East Fork Horsehead Creek, Johnson Co., Arkansas. 25. Male terminalia, dorsal. 26. Apical segment upper limb of epiproct, dorsal. 27. Surface detail apical segment upper limb of epiproct, dorsal. 28. Epiproct apex and 8th tergal process, lateral. 29. Abdominal tergal lobes, dorsal. 30. Abdominal tergal lobes, anterodorsal.