LESTONIIDAE

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 : 969

LESTONIIDAE China

Historical: China (1955) described the lestoniids as a new subfamily of Plataspididae based on characters of the hind wing venation and the two-segmented tarsi.

China and Miller (1959) raised the group to family status. China (1963), McDonald (1970), and Schaefer (1993a) retained the familial ranking. Gapud (1991) considered Lestoniidae and Plataspididae as sister

groups, with five homoplasious characters supporting the relationship: well-developed triangulin (an erroneous interpretation; see explanation of the characters), two-segmented tarsi, obsolete frena, enlarged scutellum that covers the abdomen, and contiguous ninth paratergites. The Plataspididae is unique in having almost the entire pleural region covered by the evaporative area, whereas the Lestoniidae has an extremely reduced evaporative area. Fischer (2000, 2006) considered the disc-like organs of the Lestoniidae to be homologous with the Pendergrast̕s organs of the Acanthosomatidae and associated the two taxa on that basis. Additional characters suggesting a common stem-species for Acanthosomatidae and Lestoniidae include the structure of the male genital segments, the arrangement of the abdominal scent-gland openings, and the number of tarsomeres. McDonald (1969, 1970), Schaefer (1993a), and other authors erroneously considered the spermathecal flanges to be absent in Lestoniidae (see explanation of characters); Fischer (2000) corrected this misinterpretation and illustrated the spermatheca of Lestonia haustorifera China as possessing a proximal flange.

Analytical result: The placement of the Lestoniidae has been controversial, in large part because of its many novel morphological attributes. Because the most commonly collected species is small, and usually taken in very limited numbers, acquiring a decent sample of specimens takes considerable effort in the field. Our own fieldwork has allowed the present analysis to benefit from the recently published morphological analysis of Fischer (2000) and DNA sequence data for the group. Our morphological analyses (e.g. Figs 43 and 44 ) offer a less than convincing placement for the group, and only the PIWE result supports a sister-group relationship with Acanthosomatidae as proposed by Fischer (2000). However, all of our results that include DNA sequence data show the Lestoniidae + Acanthosomatidae forming a monophyletic group. The molecular data alone treat Lestonia as part of the Acanthosomatidae ( Figs 45 and 46 ), whereas the combined analyses always place Lestonia as the sister group of the Acanthosomatidae sensu stricto ( Figs 51–55 ). Morphological characters supporting the monophyly of the former grouping include: tarsi two-segmented (291), abdominal sternite VIII in males at most partially covered by segment VII (400), and Pendergrast̕s organ present in females (441).

Figures

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 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.

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.