Invasive Stink Bugs and Related Species (Pentatomoidea)

36 Invasive Stink Bugs and Related Species (Pentatomoidea)

within the Pentatomoidea. Results in Grazia et al. (2008) varied according to the analysis performed; the
morphological evidence pointed to a basal position, whereas molecular data suggested that the family is
a derived taxon related to Pentatomidae. Both analyses, as well as another molecular study by Wu et al.
(2016) suggested a sister group relationship between the Acanthosomatidae and the Lestoniidae.
Members of this family, in general appearance, resemble pentatomids, being approximately the same
size (5-20 mm) and shape and having a more or less triangular scutellum (with the frena extending about
three-fourths the lateral distance). They differ from most species of Pentatomidae, however, by their hav-
ing two-segmented tarsi, the males have the posterior margin of abdominal segment VII broadly emar-
ginated, leaving segment VIII broadly exposed (Figure 2.1L), the females usually have Pendergrast’s
organs [i.e., glandular abdominal organs that are usually rounded or oval in shape and are located on
abdominal sternites V through VII, or only on VII in some species; these are usually lacking in species
that exhibit maternal care (Fischer 2006, Tsai et al. 2015)], and they lack a dilation and sclerotized rod in
the spermathecal duct (Schuh and Slater 1995, Schwertner and Grazia 2015). Except for a small group of
Madagascan genera that has four-segmented antennae (Kment 2006), they have five-segmented antennae.
The mesosternum is often strongly carinate medially (Figures 2.1J, K) (subfamily Acanthosomatinae),
and abdominal sternite III is often armed with an anteriorly directed spine or tubercle. The trichobothria

A B

C

D E F

GH

I

FIGURE 2.2 A, Piezosternum thunbergi, thoracic pleura and base of abdomen, lateral view; B, Dinidor mactabilis,
thorax and anterior abdomen, lateral view; C, Piezosternum thunbergi, head and thorax, ventral view; D, Piezosternum
thunbergi, antennae; E, Piezosternum thunbergi, thorax and abdomen, dorsal view; F, Dinidor mactabilis, antennae;
G, Nopalis sulcatus, posterior abdomen, ventral view; H, Elasmostethus ligatus placidus, posterior abdomen, ventral view;
I, Lanopis rugosus, thorax, ventral view.