Higher Systematics of the Pentatomoidea 135
are disc-like, sometimes reaching to the lateral margins of the metapleura; the associated evaporative
areas are relatively large. Both macropterous and brachypterous forms occur; the macropterous forms
have each corium divided into an endo- and exocorium, and the claval commissure is present; the fore
wings of brachypterous forms are shortened, ‘staphylinoid’, and distally truncate. Coxal combs, com-
posed by broad and flattened setae, are present; and the tarsi are three-segmented.
Macropterous morphs of this family possess a stridulatory mechanism similar to that found in the
Cydnidae with the stridulitrum on the ventral surface of the posterior anal vein (postcubitus in earlier
papers) of the hind wing and the plectrum on the anterolateral margin of abdominal tergite I. Jacobs
(1989) indicated that the South African species had a pair of trichobothria on each side of abdominal
segments III through VII (Thaumastella elizabethae Jacobs has only a single trichobothrium on each
side of segment VII); he further indicated that the pair on segment III was nearly longitudinal, and each
subsequent pair became more oblique until the pair on segment VI was nearly transverse. The female
spermathecal bulb is ball-shaped, lacking diverticula, and there is no dilation or sclerotized rod.
The type genus and species, Thaumastella aradoides Horváth (Figure 2.16J) was originally described
as a member of the Lygaeidae sensu lato (Horváth 1896). Seidenstücker (1960) noted that thaumastellids
lacked the characteristic lanceolate ovipositor of the lygaeoids and proposed a new subfamily for them
within the Lygaeidae. This prompted Štys (1964) to elevate the group to family status. Both Štys (1964)
and Dolling (1981) considered the Thaumastellidae to be related to the Cydnidae with Dolling propos-
ing it to be the sister group of the rest of his broadly conceived Cydnidae. Jacobs (1989) indicated that
many of the characters once thought to be unique to the Thaumastellidae were found in some species of
Cydnidae. He did indicate that some features of the male genitalia and the presence of an m-chromosome
seemed to be unique to this family. Jacobs et al. (1989) also found that the defensive secretions of thau-
mastellids shared more components with the lygaeoids than it did with other pentatomoids. The presence
of an m-chromosome, which is present in most lygaeoids and absent in all other pentatomoids prompted
Henry (1997) to suggest that the thaumastellids might not belong in the Pentatomoidea after all. Based
on morphological characters, the phylogenetic study by Grazia et al. (2008) placed the Thaumastellidae
within the Pentatomoidea and, more specifically, within the Cydnidae, similar to the classification pro-
posed by Dolling (1981). Based on molecular data, however, placement of the thaumastellids was vari-
able; as such, Grazia et al. (2008) decided to leave this group as a family until further studies could be
completed.
Jacobs (1989) indicated that most of the specimens of Thaumastella namaquensis Schaefer and Wilcox
he had collected were “under fairly large stones in cavities which are exposed when the stones are
removed.” He also collected individuals on the ground near the stones, especially at dusk, and noted that
they seemed reluctant to leave their shelters. He speculated that they might be feeding on seeds that the
wind had blown up against the stones. He indicated that nymphs were found only in April. Jacobs (1989)
also provided some notes on the biology of his new species, T. elizabethae, including a host plant record –
seeds of Pharnaceum aurantium (DC) Druce [Aizoaceae]. Interestingly, he noted that it appeared that
individuals had difficulty freeing their stylets from the seeds; even when disturbed, the individuals could
be seen scurrying off with the seeds still attached to their mouthparts.
2.2.18 Thyreocoridae Amyot and Serville, 1843
This is another family that has had a complicated taxonomic history. The Thyreocoridae was proposed
(as Thyréocorides) by Amyot and Serville (1843) for a group of genera not only including Thyreocoris
and Strombosoma Amyot and Serville but also Canopus (Canopidae) and several genera now included
in the Plataspidae. Uhler (1872) proposed Corimelaenidae for the New World genera Corimelaena and
Galgupha Amyot and Serville, genera that Amyot and Serville had grouped with the scutellerid genus
Odontoscelis. Fieber (1860) and Stål (1876) treated Corimelaena and Thyreocoris as members of the
family Cydnidae. Lethierry and Severin (1893) catalogued the Corimelaeninae as a subfamily of a broad
Pentatomidae. Later, Horváth (1919) treated this group as a subfamily within the Cydnidae and rec-
ognized two tribes, the Canoparia and the Thyreocoraria. McAtee and Malloch (1928) excluded the
Canoparia from the Thyreocorinae, and, subsequently (1933), treated this group as a subfamily of the
Pentatomidae. Froeschner (1960) recognized the Cydnidae and the Corimelaenidae (including both New