Allocapnia, RICKERI

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 : 66

ALLOCAPNIA RICKERI GROUP

Ross & Ricker (1971) placed six species ( A. cunninghami Ross & Ricker 1971 ; A. perplexa Ross & Ricker 1971 ; A. rickeri Frison 1942 ; A. sandersoni Ricker 1952 ; A. stannardi Ross 1964 ; A. zola Ricker 1952 ) in this group and suggested, primarily on the basis of female characters, these form two “well- marked complexes of three species each”. The line of fusion between abdominal sterna 7-8 includes a sclerotized ridge in females of A. cunninghami , A. perplexa and A. zola , whereas females of A. rickeri , A. sandersoni and most A. stannardi lack such a structure. Subsequently, A. harperi Kirchner 1980 , was added to the second complex.

The epiproct upper limb for species in this group, is typified by a long basal segment and a relatively short, somewhat bulbous apical segment ( Figs. 79 , 85 , 91 , 97 ), a feature shared with members of the A. forbesi group. The apical segment bears a distal patch of densely packed, wave-like spikes ( Figs. 81 , 87 ) and the basal segment has a relatively broad, shallow longitudinal groove. The lower limb bears a distinct notch offsetting the apical spoon ( Fig. 100 ). Abdominal tergum 8, or 7 and 8, bear dorsal processes ( Figs. 90 , 95 , 112 ); those on tergum 8 are typically bilobed but in one species, A. zola , this structure is trilobed and a second process, also present on segment 8, is displaced toward the anterior segmental margin ( Fig. 115 ). In Ross & Ricker’s analysis, A. stannardi and A. rickeri were considered sister species with A. sandersoni more distantly related, and the other complex was presented as an unresolved trichotomy. The A. rickeri group shares “ancestor number 15” with A. jeanae Ross 1964 , in this analysis ( Ross & Ricker 1971).

We are unable to provide a definitive hypothesis for relationships within the A. rickeri group, but based primarily on tergal lobe variations, we could propose one subgroup in which the 8 th tergal lobe notch is at least 75 μm wide ( A. harperi , A. perplexa , A. rickeri , A. stannardi ; Figs. 90 , 96 , 101 , 114 ) and another in which the 8 th tergal lobe notch is no more than 45 μm wide ( A. cunninghami , A. sandersoni , A. zola ; Figs. 83 , 108 , 120 ). Within the first group, A. harperi , A. stannardi , and A. rickeri share ear-like lobes on the 8 th tergal process, whereas those of A. perplexa are not ear shaped, however we offer no resolution for the former trichotomy. In the A. cunninghami , A. zola , A. sandersoni subgroup, the former two species each share a small lobe on tergum 7 and also a small median projection on the 8 th tergal process which supports a sister group relationship between these two species. Unfortunately, we have no probable apomorphy which unites this latter subgroup.

Figures

Figs. 79-84. Allocapnia cunninghami, tributary Little Trammel Creek, Sumner Co., Tennessee. 79. Male terminalia, dorsal. 80. Apical segment upper limb of epiproct tip, dorsal. 81. Surface detail apical segment upper limb of epiproct, dorsal. 82. 8th tergal process and epiproct tip, lateral. 83. 8th tergal process and epiproct tip, anterodorsal. 84. 7th tergal process, dorsal.

Figs. 85-90. Allocapnia harperi, Station Spring Creek, Tazewell Co., Virginia. 85. Male terminalia, dorsal. 86. Apical segment upper limb of epiproct, dorsal. 87. Apical segment upper limb of epiproct tip, dorsal. 88. Surface detail apical segment upper limb of epiproct, dorsal. 89. 8th tergal process and epiproct tip, lateral. 90. 8th tergal process and epiproct tip, anterodorsal.

Figs. 91-96. Allocapnia perplexa, East Fork Bledsoe Creek, Sumner Co., Tennessee. 91. Male terminalia, dorsal. 92. Apical segment upper limb of epiproct tip, dorsal. 93. Surface detail apical segment upper limb of epiproct, dorsal. 94. 8th tergal process and epiproct tip, lateral. 95. 8th tergal process and epiproct tip, dorsal. 96. 8th tergal process, 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. 109-114. Allocapnia stannardi, 1 mile W Newfound Gap, Sevier Co., Tennessee. 109. Male terminalia, dorsal. 110. Apical segment upper limb of epiproct tip, dorsal. 111. Surface detail apical segment upper limb of epiporct, dorsal. 112. Male terminalia, lateral. 113. Abdominal tergal processes, dorsal. 114. Abdominal tergal processes, anterodorsal.

Figs. 115-120. Allocapnia zola, Stoney Fork Reed Creek, Wythe Co., Virginia. 115. Male terminalia, dorsal. 116. Apical segment upper limb of epiproct tip, dorsal. 117. Surface detail apical segment upper limb of epiproct, dorsal. 118. Abdominal tergal processes, dorsal. 119. Male terminalia, lateral. 120. Abdominal tergal processes, anterodorsal.

Figs. 103-108. Allocapnia sandersoni, Little Red River, Searcy Co., Arkansas. 103. Male terminalia, dorsal. 104. Apical segment upper limb of epiproct tip, dorsal. 105. Male terminalia, lateral. 106. 8th tergal process and epiproct tip, lateral. 107. 8th tergal process and epiproct tip, dorsal. 108. 8th tergal process, anterodorsal.