Higher Systematics of the Pentatomoidea 97
genera Prionocompastes Breddin and Zhengius Rider (= the preoccupied Tibetocoris Zheng and
Liu), are obviously closely related to Rolstoniellus as well.
Little has been written about this tribe since its inception. Distant (1902) defined the group as “pos-
sessing a greater breadth of body with the head broader at the apex and the scutellum usually less acumi-
nate. The species are obscurely coloured.” He also mentioned that the base of the abdomen is unarmed.
We have examined specimens of Agathocles, Amasenus, Critheus, Exithemus, Prionocompastes,
Rolstoniellus, and Zhengius. Members of Critheus and Exithemus are elongate oval and punctate but
without projections or protuberances. Critheus has a submarginal line of punctures paralleling the mar-
gins of the head and pronotum that is very similar to that seen in Axiagastus (Axiagastini). Members
of Amasenus are larger with the humeri prominent and truncately produced, the scutellum has a pair
of large ‘bumps’ basally, and there are also small teeth along the anterolateral pronotal margins. All
three genera have a similar structure of the thoracic sterna and ostioles. The mesosternum is carinate,
especially anteriorly. The ostiolar rugae are elongate, curving anteriorly, and then becoming rather thin,
forming a narrow line-like ridge in the apical third. The species of Amasenus and Critheus have the
rostrum quite elongate, reaching well onto the abdomen; in fact, in one species of Critheus, the rostrum
reaches the base of the genital segment. In some specimens of Exithemus we examined, the rostrum
reaches to the hind coxae. In all specimens examined, the spiracles appeared unusually large; the pair on
abdominal segment II was at least partially exposed, and, in Amasenus, there was, at least, a pair of small
spiracles on abdominal segment VIII of the females. Prionocompastes, Rolstoniellus, and Zhengius (the
first and last currently in the Pentatomini) are characterized by serrate anterolateral margins of the pro-
notum and broadly expanded, apically denticulate or lobate humeri (Figure 2.32A); the strongly reduced
ruga of the metathoracic scent gland ostiole; and two-segmented tarsi. They obviously form a complex
of closely related species, and their generic level differences (particularly those of Rolstoniellus and
Zhengius) are unclear. In spite of its 3-segmented tarsi, Liicoris Zheng and Liu (see Section 2.2.10.7.46)
is probably related to these genera.
The tribe is morphologically very heterogenous and likely non-monophyletic. On the other hand, there
is little to distinguish its type genus (Rolstoniellus) and related genera from certain members of the
Pentatomini; therefore, it is probable that this tribe eventually will be subsumed into the Pentatomini.
The genus Critheus has been revised (Ghauri 1963). Two species of Critheus, C. indicus (Distant) and
C. lineatifrons Stål, have been recorded feeding on, and sometimes damaging, bamboo (Hoffmann 1931,
1932; Cheo 1935; Zheng 1986, 1994; Zhang et al. 1995).
2.2.10.7.40 Sciocorini Amyot and Serville, 1843
Amyot and Serville (1843) proposed two family-level names that are now associated with this tribe;
Pododides was based on their new genus Pododus Amyot and Serville, and Sciocorides was based on the
genus Sciocoris Fallén. In 1866, Mulsant and Rey proposed the family-level name Oploscelates, based
on their new genus Oploscelis, which now is considered to be a subgenus of Menaccarus Amyot and
Serville. Stål (1876) essentially synonymized all three of the above tribes when he included Pododus,
Sciocoris, and Menaccarus in his “Sciocoris et affinia” group.
This tribe contains 16 genera and subgenera and about 126 species (Table 2.3) (most of them in the
genus Sciocoris) and occurs worldwide, although the taxa are most diverse in the Palearctic Region.
Members of this tribe tend to be small to medium in size, usually somewhat flattish (except several
New World species are more robust) (Figures 2.24C, D; 2.32B). The lateral margins of the head and
especially the pronotum are broadly explanate, shelf-like. The ocelli are somewhat remote from the
relatively small compound eyes, and the antenniferous tubercles are not visible from above. The scutel-
lum is somewhat enlarged, spatulate. The prosternum and mesosternum are shallowly to deeply sulcate,
not carinate medially (except a faint carina is evident in Trincavellius Distant [Figure 2.24D]), and the
metasternum is flattish to slightly concave. The ostiolar rugae are usually short and auriculate (a little
longer in the Australian genus Kapunda Distant) with the associated evaporative areas also quite small.
There are at least two New World species (S. crassus Ruckes and S. longifrons Barber) presently placed
in Sciocoris that have the inner mesial margins of the propleura produced, forming a ridge on either side
of the rostral groove.