Allocapnia RICKERI
Creators: name: Stark, Bill P.
name: Kondratieff, Boris C.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Capniidae
Allocapnia

description: <i>ALLOCAPNIA RICKERI</i> GROUP Ross &amp; Ricker (1971) placed six species (<i>A. cunninghami</i> Ross &amp; Ricker 1971; <i>A. perplexa</i> Ross &amp; Ricker 1971; <i>A. rickeri</i> Frison 1942; <i>A. sandersoni</i> Ricker 1952; <i>A. stannardi</i> Ross 1964; <i>A. zola</i> 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 <i>A. cunninghami</i>, <i>A. perplexa</i> and <i>A. zola</i>, whereas females of <i>A. rickeri, A. sandersoni</i> and most <i>A. stannardi</i> lack such a structure. Subsequently, <i>A. harperi</i> 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 <i>A. forbesi</i> 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, <i>A. zola,</i> this structure is trilobed and a second process, also present on segment 8, is displaced toward the anterior segmental margin (Fig. 115). In Ross &amp; Ricker’s analysis, <i>A. stannardi</i> and <i>A. rickeri</i> were considered sister species with <i>A. sandersoni</i> more distantly related, and the other complex was presented as an unresolved trichotomy. The <i>A. rickeri</i> group shares “ancestor number 15” with <i>A. jeanae</i> Ross 1964, in this analysis (Ross &amp; Ricker 1971). We are unable to provide a definitive hypothesis for relationships within the <i>A. rickeri</i> 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 (<i>A. harperi, A. perplexa, A. rickeri, A. stannardi</i>; Figs. 90, 96, 101, 114) and another in which the 8 th tergal lobe notch is no more than 45 μm wide (<i>A. cunninghami, A. sandersoni, A. zola;</i> Figs. 83, 108, 120). Within the first group, <i>A. harperi, A. stannardi,</i> and <i>A. rickeri</i> share ear-like lobes on the 8 th tergal process, whereas those of <i>A. perplexa</i> are not ear shaped, however we offer no resolution for the former trichotomy. In the <i>A. cunninghami, A. zola, A. sandersoni</i> 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.
description: Published as part of <i>Stark, Bill P. &amp; 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, pp. 45-77 in Illiesia 8 (5)</i> on page 66, DOI: 10.5281/zenodo.4760725
description: {"references": ["Ross, H. H. &amp; W. E. Ricker. 1971. The classification, evolution, and dispersal of the winter stonefly genus Allocapnia. Illinois Biological Monographs 45: University of Illinois Press, Urbana, Illinois. 166 pp.", "Frison, T. H. 1942. Studies of North American Plecoptera with special reference to the fauna of Illinois. Bulletin of the Illinois Natural History Survey, 22: 235 - 355.", "Ricker, W. E. 1952. Systematic studies in Plecoptera. Indiana University Publications, Science Series No. 18. Indiana University Press, Bloomington, Indiana. 200 pp.", "Ross, H. H. 1964. New species of winter stoneflies of the genus Allocapnia (Plecoptera, Capniidae). Entomological News, 75: 169 - 177.", "Kirchner, R. F. 1980. A new Allocapnia from Virginia (Plecoptera: Capniidae). Entomological News, 91: 19 - 21."]}