Stirotarsinae, Grazia & Schuh & Wheeler, 2008

Grazia, Jocelia, Schuh, Randall T. & Wheeler, Ward C., 2008, Phylogenetic relationships of family groups in Pentatomoidea based on morphology and DNA sequences (Insecta: Heteroptera), Cladistics 24, pp. 932-976 : 970-971

PENTATOMIDAE Leach sensu lato (including Aphylinae and Cyrtocorinae )

Historical: Rolston and McDonald (1979) recognized five subfamilies in Pentatomidae from the Western

Hemisphere ( Asopinae , Discocephalinae , Edessinae , Pentatominae , and Podopinae ). Schuh and Slater (1995) included two additional subfamilies from the Eastern Hemisphere ( Phyllocephalinae , and Serbaninae) and included the Cyrtocoridae as a subfamily, giving a total of eight subfamilies. Rolston (1981) proposed Ochlerini as a new tribe in Discocephalinae . Ahmad and Kamaluddin (1988, 1990) and Kamaluddin and Ahmad (1988) established a tribal classification of the Phyllocephalinae recognizing four tribes: Cressonini, Megarrhamphini, Phyllocephalini , and Tetrodini. In the Pentatominae, Hassan and Kitching (1993) provided a cladistic analysis of some of the tribes but did not propose a revised formal classification. For the Podopinae , Davidová -Vilimová and Štys (1994) recognized five tribes: Brachycerocorini, Deroploini, Graphosomatini , Podopini , and Tarisini; Schuh and Slater (1995) recognized eight tribes (Aeptini, Diemeniini , Halyini , Lestonocorini, Mecideini , Myrocheini, Pentatomini , and Sciocorini ). Recently, Rider (2000) proposed a new subfamily, Stirotarsinae , for the monotypic genus Stirotarsus Bergroth , based on the unique antennal, rostral, and tarsal characters, along with the relatively rare ostiolar, tibial, and spiracular characters. Cassis and Gross (2002) summarized the suprageneric classifications of Pentatomidae of some earlier authors who had a broad concept of the family, incorporating the dinidorids, plataspids, tessaratomids, and scutellerids (e.g. Kirkaldy, 1909; Miller, 1956; China and Miller, 1959). Most recently, Rider (2006) recognized ten subfamilies within Pentatomidae [Aphylinae, Asopinae , Cyrtocorinae, Discocephalinae , Edessinae , Pentatominae , Phyllocephalinae , Podopinae , Serbaninae (see discussion under Phloeidae ), and Stirotarsinae ], the Pentatominae comprising 42 nominal tribes. Gapud (1991) considered the Pentatomidae to be probably the most ‘‘advanced’’ family in the Pentatomoidea , supported by six apomorphies: the dorsally membranous eighth abdominal segment in males, the rigid phallotheca, the vesica without a conjunctival sheath (an extremely variable character within the Pentatomoidea , as are the majority of male genitalic characters), the fixed position of the ejaculatory reservoir on the phallotheca, triangulin present, and the completely fused 2nd valvifers (shared with Scutelleridae ).

Aphylinae Bergroth: This exclusively Australian group, known from two genera and three species, was first reported in the description of Aphylum syntheticum Bergroth (1906) . The author proposed a new subfamily, considering A. syntheticum to be an isolated taxon combining characters of the pentatomoid family-groups Scutellerinae , Graphosomatinae, Plataspinae, and Pent-

atominae. Schouteden (1906b) described the new species A. bergrothi and was inclined to place Aphylinae in the neighborhood of the Scutellerinae . Aphylum was monographed by Schouteden (1906a) and subsequently raised

to family rank by Reuter (1912). China (1955), in establishing his new subfamily Lestoniinae under the Plataspididae , compared it to Aphylum ; China (1963) properly corrected his statement of 1955 concerning the absence of trichobothria in both subfamilies. McDonald (1970) discussed the morphology and relationships of Aphylum . Gross (1975), considering it to be closely related to the pentatomid genera Tarisa Amyot & Serville and Kumbutha Distant , returned the taxon to subfamily status. Schuh and Slater (1995) and Cassis and Gross (2002) accepted family rank for the group. Štys and Davidová -Vilimová(2001) described Neoaphylum to include the new species N. grossi . Rider (2006) treated the taxon as a pentatomid subfamily.

Cyrtocorinae Distant : This exclusively Neotropical taxon was recently revised by Packauskas and Schaefer (1998); it includes four genera and 11 species. Besides the record of Cyrtocoris trigonus (Germar) from California ( Banks, 1910; Horváth, 1916; Brailovsky et al., 1988), Packauskas and Schaefer (1998) agreed with Henry and Froeschner (1988) that the lack of any subsequent discovery of Cyrtocoris White in the United States makes Bank̕s record suspect. Packauskas and Schaefer (1998) stated that Kormilev (1955) appears to have been the first person to present evidence for raising Cyrtocorinae to family rank as distinct from the Pentatomidae (based on features of the fore- and hindwing venation, the position of the second abdominal spiracle in the membrane, and the placement of the abdominal trichobothria), allying Cyrtocoridae with Cydnidae ; but, at the same time, they argued that placement of the anterior trichobothria lateral to the spiracles, also found in the pentatomid subfamily Discocephalinae , represents convergence. The differences in the venation of fore- and hindwings may be an issue of degree; the second abdominal spiracle, lying in the membranous part of the segment, needs a more complete survey, as this situation varies in different groups of pentatomids. Gapud (1991) separated Cyrtocorinae (as a pentatomid subfamily) from the rest of Pentatomidae by the absence of a triangulin, 2nd valvifers with a distinct median fusion line, and male phallotheca relatively flexible. Packauskas and Schaefer (1998) considered the presence of a triangulin, 2nd valvifers completely fused, and a rigid phallotheca as apomorphies of Pentatomidae minus Cyrtocoridae . Gapud (1991) placed the Cyrtocorinae + Pentatomidae sensu stricto as the most apical taxa, ‘‘strongly separated from the rest of Pentatomoidea’’ by the loss of first valvulae, the absence of the gonangulum, the invagination and dilation on the spermathecal duct, the retention of membranous flaps of the 2nd valvulae, and the

presence of an antero-posterior pair of basal sclerites on the spermathecal base.

Analytical result: This, the largest family-group within the Pentatomoidea , is resolved as monophyletic in every

analysis—except the 16S, 18S, and CO1 partitions—tes-tifying to the strength of character support for it. Morphological characters that consistently support the recognition of a broadly conceived Pentatomidae include: the loss of gonapophyses 8 and the first rami (452), gonapophyses 9 reduced and fused to gonocoxites 9 (492), gonangulum absent (502), and the ductus receptaculi dilated and invaginated, forming three distinct walls (511). The overall sample of taxa and characters for the Pentatomidae in this study is too small to provide a robust scheme at the subfamily and tribal level. We can comment, however, on the relationships of the Pentatomidae sensu stricto with the familygroup taxa Aphylinae and Cyrtocorinae .

Discussions of the systematic position and rank of the Aphylinae and Crytocorinae have occupied considerable space in the literature. Many of those discussions have focused on differences instead of similarities. We cannot adduce information from sequence data for these two taxa. We can point out, however, that our morphological analysis offers strong character support for the grouping ( Cyrtocorinae (Aphylinae + Pentatomidae sensu stricto )). Thus, it would seem that discussions concerning whether or not Cyrtocorinae and Aphylinae should be recognized at the family level, or as part of the Pentatomidae , simply amount to preference regarding degree of difference, rather than a substantive interpretation of relationships. We have chosen to treat both taxa at subfamily rank in recognition of their many shared similarities with the Pentatomidae sensu stricto.

Sister-group relationships of the Pentatomidae sensu lato at the next higher level are not as clear-cut. Nonetheless, the totality of the evidence seems to point towards a sister-group relationship with the Acanthosomatidae + Lestoniidae , as suggested in Figs 45, 46 , and 51–53.

Figures

Figs 45–48. 45. One of two trees derived from analysis of combined molecular data with 1: 1 indel ⁄transition–transversion cost ratio. 46. Single tree derived from analysis of combined molecular data with 2: 2 indel ⁄ transition–transversion cost ratio. 47. Single tree derived from analysis of ~500 bp of 16S rRNA data using 1: 1 indel ⁄ transition–transversion cost ratio. 48. Single tree derived from analysis of ~1800 bp of 18S rRNA using 1: 1 indel ⁄ transition–transversion cost ratio.