92 Invasive Stink Bugs and Related Species (Pentatomoidea)
2.2.10.7.32 Opsitomini Cachan, 1952
Opsitomaria was proposed by Cachan (1952) to contain his new genus Opsitoma. This tribe still contains
just a single genus with one species (Table 2.3), endemic to Madagascar. It is a medium sized spe-
cies, somewhat elongate rounded in shape (Figure 2.31A). It is brown in color, and has the head wider
subapically than just in front of the eyes. The mesosternum is sulcate, with no carina medially. The
ostiolar rugae are quite short and auriculate; the associated evaporative areas are also relatively small.
The second antennal segment is extremely short, almost giving the appearance that the antennae are
four-segmented. The juncture between the distal two tarsal segments is rather weak, again giving the
impression that the tarsi are only two-segmented.
The sulcate mesosternum could ally this genus with the Aeptini, Myrocheini, or the Diploxyini.
Further research is needed to see if this is a valid tribe, or whether it might fall into one of these tribes.
2.2.10.7.33 Pentamyrmecini Rider and Brailovsky, 2014
This recently described tribe contains a single genus and species, Pentamyrmex spinosus Rider and
Brailovsky (Figure 2.31B) from Thailand (Rider and Brailovsky 2014, 2015) (Table 2.3). The general
appearance of this species is so distinctive that its placement in a superfamily was initially difficult.
Photos of this insect were sent to several notable heteropterists with the hope of determining the cor-
rect superfamily and then the family. The female genital plates and the five-segmented antennae place
this creature in the Pentatomidae. As the scientific name implies, this species appears to be an ant
mimic. We know of no other example of ant mimicry within the Pentatomoidea except possibly the genus
Caridophthalmus (Figures 2.12D, 2.21B), currently placed in the Diemeniini.
The only known individual of this taxon is just over 6 mm in length, black with a few white spots.
Members of this tribe have the head strongly declivent, almost vertical (Figure 2.14E). The ocelli are pres-
ent, but are relatively small. The antennae are five-segmented, with the first segment not reaching the apex
of the head. The bucculae are large, each obtusely lobed posteriorly. The pronotum has a deep transverse
constricture dividing it into two equal halves; the lateral margins are not edged or reflexed but are evenly
rounded. The lateral pronotal margins are provided with several large spines; each humeral angle is formed
into a rather large spine, which, in turn, possesses several small spines (Figure 2.31B). The scutellum is
elongate-triangular with an upwardly directed spine in each basal angle and a larger bifurcate spine arising
from the apex (Figures 2.14E, F). The coria are slightly constricted medially each with a pale white spot
nearby lending to the appearance of a narrow waste. There are also two strategically placed white waxy
spots on the pleural regions (one on each side), also giving the appearance of constrictures (for possible ant
mimicry). The clavi are quite long and slender, extending and meeting beyond apex of scutellum at a point,
not really forming a claval commissure. The thoracic pleurites are nearly vertical; the ostiolar apparatus is
reduced with the ostiolar rugae short and auriculate. The posterolateral connexival angles are not spinose
except for those of segment V, each of which has a large upwardly directed spine (Figure 2.14E).
2.2.10.7.34 Pentatomini Leach, 1815
This is a large, widespread tribe with current members occurring in both the New World and Old World.
It contains 56 genera and 316 species (Table 2.3). Again, as with many of the larger tribes, included
members are quite variable. In fact, this may be one of the more poorly defined tribes within the family.
Basically, members of this tribe are medium to large in size, often brown or mottled brown and white
(Figures 2.23A-H; 2.31C-F, H) and usually have the base of the abdomen produced into an anteriorly
directed spine or tubercle. It appears that this last character has arisen multiple times within the family
and secondarily has been lost several times, making it quite difficult to determine its utility. This charac-
ter is not even consistent within the nominate genus Pentatoma; most species have an armed abdominal
venter, but there are several species in which the base of the abdomen is unarmed. Additionally, in some
of the genera, the abdominal spine or tubercle is free apically, reaching between the hind coxae or further
(Rolston et al. 1980, Pentatomini, section two); in several other genera, however, the apex of the abdomi-
nal spine is not free, but is met by the posterior margin of an elevated metasternum that may or may not
be notched (Rolston et al. 1980, Pentatomini, section three). At present, taxa having either of the above
two conditions are included within the Pentatomini, but this may in the future serve as way to divide this