PLATASPIDIDAE Dallas, 1851

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 : 964

PLATASPIDIDAE Dallas

Historical: Dallas (1851) was the first worker to recognize this Old World taxon at the family-group level. Stål (1864) treated it as a subfamily of

Pentatomidae . Leston (1952) raised it to family status (= Brachyplatidae). Most modern workers do not recognize an infrafamilial classification, with the exception of Rider (2006), who recognized the subfamilies Brachyplatidinae and Plataspidinae . Gapud (1991) considered Plataspididae as the sister group of the Lestoniidae ( Fig. 1f ), in spite of the variability of the characters that grouped them (see comments under Lestoniidae ). One character that was treated as

synapomorphic for the Pentatomoidea by Gapud (1991) was the presence of a pair of ring sclerites (chitinellipsen; Dupuis, 1955). Gapud treated a single ring sclerite as plesiomorphic because that is the

condition he found in the Coreidae that he examined. His observations indicated that these structures were absent in the Plataspididae , Acanthosomatidae , and Cyrtocorinae , a condition that he treated as a reversal. Our observations in part contradict those of Gapud (1991), as we found a pair of ring sclerites to be present in the species of Plataspididae and Acanthosomatidae that we examined, but in accordance with the observations of Gapud (1991) we did not observe ring sclerites in the Cyrtocorinae . Because the presence of ring sclerites varies greatly within families and subfamilies, we have not included this character in our morphological matrix.

Analytical result: The Plataspididae resembles, at least superficially, the Canopidae and Megarididae , and indeed groups with them in our morphological analyses on the basis of one or more of the following characters ( Figs 42–44 ): body sphaeroid (12), scutellum well developed (163), frena obsolete (182), and gonocoxites 9 joined by membrane (461). In the molecular and total evidence analyses, the position of the Plataspididae is more basal and always dissociated from the Canopidae , although not from the Megarididae ; here it forms the sister group (sometimes in conjunction with other taxa) of nearly all Pentatomoidea except Urostylididae and Saileriolidae . These results suggest that the enlarged scutellum is the result of convergence, a conclusion that can be drawn from its observed occurrence in many groups of pentatomoids which show little relation to one another on the basis of other characters. Although the relatively basal placement of the Plataspididae contradicts the theories of all prior authors ( Fig. 1 ), this position is not altered by changing the taxon composition or the cost regimes in the combined analyses ( Figs 51–55 ). The monophyly of the Plataspididae is supported in our analyses by the condition of laterotergites 9 being contiguous and partially or totally covering segment X (470).

Figures

Fig. 1. Diagrams showing hypotheses of Pentatomoidea classifications (Bonatto, 1988): (a) Singh-Pruthi, 1925; diagram and discussion; (b) Leston, 1958; Fig. 5; (c) China and Miller, 1959; Fig. 1; (d) Cobben, 1968; figs 269–270; (e) Cobben, 1978; several figures and text; (f) proposed phylogeny of Pentatomoidea (Gapud, 1991). [Captions removed; all taxon names rendered in current spellings; part (f) not from Bonatto (1988).]

Fig. 42. Strict consensus of 96 most parsimonious trees for full-taxon morphological data set, with unsupported nodes supressed. Length = 207; consistency index = 42; retention index = 86. (d) Non-homoplasious; (s) homoplasious.

Fig. 43. Strict consensus of three trees derived from successive weighting of the results shown in Fig. 42. (d) Non-homoplasious; (s) homoplasious.

Fig. 44. Strict consensus of 12 trees derived from implied weighting analysis of morphological data using PIWE. (d) Non-homoplasious; (s) homoplasious.

Figs 49–52. 49. Single tree derived from analysis of ~470 bp of 28S rRNA using 1: 1 indel ⁄ transition–transversion cost ratio. 50. Single tree derived from analysis of ~1100 bp of COI mtDNA using 1: 1 indel ⁄transition–transversion cost ratio. 51. Total evidence analysis with POY of 52- taxon data set using 1: 1 indel ⁄ transition–transversion cost ratio. 52. Total evidence analysis with POY of 52-taxon data set using 2: 2 indel ⁄ transition–transversion cost ratio.

Fig. 53. One of six trees from total evidence analysis with POY of 92-taxon data set using 1: 1 indel ⁄ transition–transversion cost ratio. (d) Non-homoplasious; (s) homoplasious.

Fig. 54. One of four trees from total evidence analysis with POY of 92-taxon data set using 1: 2 indel ⁄ transition–transversion cost ratio. (d) Non-homoplasious; (s) homoplasious.

Fig. 55. One of three trees from total evidence analysis with POY of 92-taxon data set using 2: 2 indel ⁄transition–transversion cost ratio, which had the lowest MRI value. Bremer support values are shown.