Acanthosomatinae Phylogenetic relationships of family groups in Pentatomoidea based on morphology and DNA sequences (Insecta: Heteroptera) Grazia, Jocelia Schuh, Randall T. Wheeler, Ward C. Cladistics 2008 2008-11-21 24 932 976 7NFSF Signoret Signoret 1863 [815,1223,1801,1825] Insecta Acanthosomatidae Animalia Hemiptera 37 969 Arthropoda family   Historical: This predominantly Southern Hemisphere taxon includes three subfamilies: Acanthosomatinae,  Blaudinae with two tribes Blaudini and Lanopini, and Ditomotarsinae, also with two tribes, Ditomotarsini and Laccophorellini ( Kumar, 1974). Froeschner (1999)emendedthe spelling of Blaudusinae Kumar to Blaudinae and Blaudini because the higher-taxon name was based on  BlaudusStål; we follow Froeschner̕s usage. In the cladistic analysis of Gapud (1991)the Acanthosomatidaeis related to the Dinidoridaeplus Tessaratomidaeand Scutelleridae, coming out in a relatively basal position on the cladogram ( Fig. 1f). Fischer (1994a,b), in a phylogenetic analysisof the family, stressed the monophyly of the Acanthosomatidaebased on three non-homoplastic characters and one homoplastic character: (i) presence of Pendergrast̕s organ (abdominal disc organ), (ii) segment VIII in males visible (not concealed by segment VII), (iii) females with a special organ for symbiont transmission, and (iv) openings of anterior abdominal scent glands shifted laterad, a feature shared with the Scutelleridae. Fischer (2006)described the biological context and evolution of Pendergrast̕s organ in the Acanthosomatidae, presenting a surveyof these organsin more than 100 acanthosamatid species.  Analytical result: Our morphological and total evidence analyses ( Figs 42–44and 51–55, respectively) always resolve the Acanthosomatidaeas monophyletic, a theory concordant with most prior work. Our taxon sample for DNA sequences is biased toward the Australian fauna and the subfamilies Acanthosomatinaeand Blaudinae, although we did sequence  ElasmostethusFieberfrom the Northern Hemisphere, a member of the Acanthosomatinae. The position of the group within the Pentatomoideais variable, depending on the data set being analysed. The morphological analyses treat the group as relatively basal ( Figs 42–44), whereas the molecular data always treat the group as closely associated with the Pentatomidae( Figs 45 and 46), although sometimes with a small number of other taxa involved ( Fig. 45). The 52-taxon total evidence analyses ( Figs 51 and 52) place the Acanthosomatidae+ Lestoniidaeas the sister group of the Pentatomidae, in the case of 1: 1 cost ratio also including  Thaumastella. The result of the 92-taxon analysis under a 1: 1 cost ratio ( Fig. 53) is similar to molecular and 52-taxon analyses, the 1: 2 cost ratio moves the Acanthosomatidaeto a more basal position in the cladogram ( Fig. 54), and the 2: 2 costratioincludesthe Dinidoridae+ Tessaratomidaeas part of the Acanthosomatidae+ Pentatomidaecomplex. Morphological characters supporting the monophyly of the Acanthosomatidaein both the morphological and 92-taxon total evidence analyses are the membranous abdominal tergite VIII in males ( 411) and the triangulin absent with a smooth intergonocoxal membrane between gonapophyses 8 ( 531). The 92-taxon total evidence analyses offer additional support from the obsolete claval commissure ( 172) and the claws with bristles ( 311).