Higher Systematics of the Pentatomoidea 93
group into two better defined tribes (see later discussion under Banasa in the ‘Other Unplaced Genera’
section, Section 2.2.10.7.46).
Typically, once those genera showing characteristics of other tribes (e.g., some Catacanthini, Menidini,
some Nezarini, Piezodorini, some Procleticini) have been removed, the remaining unplaced genera that
possess an armed abdominal venter have been placed in the Pentatomini. This is not totally satisfactory.
It is difficult at this time to better place these genera, and so we have chosen to continue to treat them
here until a more thorough phylogenetic analysis can be completed.
This tribe can be further characterized by several general characters, most of which have exceptions
(Tsai and Rédei 2014). The antennae are usually five-segmented. The mesosternum is usually carinate.
Interestingly, we generally define the Pentatomini as having elongate ostiolar rugae with the apices acute
to acuminate and attached to the pleura, but, in fact, this character is variable even within some genera.
For example, some members of Pentatoma and Priassus have an ostiolar ruga that is somewhat shorter;
even when the rugae are longer, they are not acuminate apically, and the apex appears to be detached
from the pleural surface (Figure 2.9F). The tarsi are three-segmented (except Phalaecus).
Because of the lack of clear-cut diagnostic characters, it is impossible to provide a universal definition of the
Pentatomini. Several genera traditionally placed into other tribes (first of all Carpocorini and Rolstoniellini)
are potentially related to Pentatomini (see further discussion under the above mentioned tribes).
There is a small group of New World genera (Adevoplitus Grazia and Becker, Evoplitus Amyot and
Serville [Figure 2.31E], Pseudevoplitus Ruckes, and an old genus in need of validation, Platencha Spinola
[Figure 2.13A]) that have the sternal structure strikingly similar to the Old World tribe Rhynchocorini. The
abdominal venter is armed at the base with an anteriorly directed spine, which, in turn, is received by the
posteriorly notched metasternum; the metasternum then joins with the elevated mesosternal carina, which
extends anteriorly onto the prosternum to near the base of the head (Figure 2.7H) (Grazia 1997). These
species, however, do not seem to belong to the Rhynchocorini, mainly because they are brown and white
mottled and more densely punctate. There is also a possibility that Nocheta Rolston, Paratibilis Ruckes,
Phaleacus, Tibilis Stål, and related genera may belong to this group - the sternal structure is essentially the
same except that the mesosternal carina is usually shorter, just reaching onto the posterior margin of the
prosternum. These genera may be a monophyletic group warranting the erection of a new tribe for their
placement. Phalaecus differs further from other pentatomines by having short flap-like bucculae (similar
to that seen in other groups, e.g., Edessinae), and the tarsi are two-segmented (Bergroth 1910).
There is another small group of Old World genera (currently placed in several different tribes) that may
form a monophyletic group. They have a relatively short abdominal tubercle, and the sternal characters
are fairly typical of more advanced pentatomoids. The ostiolar rugae, however, are rather short, dissimi-
lar to Pentatoma. Also, these taxa have a fairly distinctive head shape; it is relatively flat with the lateral
margins of the juga subparallel in front of the eyes, but, more distally, they are rather sharply angled near
the apex. Included genera are Parvacrena (currently in the Pentatomini) and Udonga (currently placed
in the Menidini). See notes under the Menidini.
There are several other genera presently placed in the Pentatomini that have some characters that
could exclude them from their placement here. For example, members of the genera Disderia Bergroth
(Central America) and Iphiarusa (Indian and Oriental regions) have the abdominal spine quite long,
reaching to or beyond the front coxae; it is flat ventrally, somewhat reminiscent of the Piezodorini. There
are several genera in which the sternal structure is similar to the pentatomines, but the ostiolar rugae
are much shorter or auriculate. These include, but are not limited to, Elsiella Froeschner, Lelia Wa l ker
(Figure 2.31F), Marghita Ruckes, Myota Spinola (Figure 2.23C), Placosternum Amyot and Serville,
Rhaphigaster Laporte (Figure 2.31H), Stictochilus Bergroth (Figure 2.23H), and Ta urocer us Amyot
and Serville. Some of these genera (Marghita and Stictochilus) are quite similar in general appearance to
species of the Euschistus group of the carpocorines and may more properly belong there. Members of the
genus Placosternum have a somewhat different thoracic sternal structure, somewhat more reminiscent of
the Evoplitus group discussed above.
The genus Janeirona Distant has a distinct ‘gestalt’, being more long and slender and parallel-sided.
The bucculae are shorter and more flap-like than what is seen in most pentatomines, perhaps the reason
Distant (1911) originally placed this genus in the Tessaratomidae. The sternal structure, although strictly
speaking, fits into the pentatomine definition, simply looks different. In many ways, Janeirona is similar