Higher Systematics of the Pentatomoidea 85
Linnavuori (1982) stated that the species of this tribe usually are found on grasses in fields, meadows,
and in forest clearings; several of the European species of Eysarcoris and Stagonomus have been associ-
ated with Lamiaceae (Derjanschi and Péricart 2005).
Recent revisions have been provided for several eysarcorine genera: Adria (Zaidi 1994, 1996), Durmia
(Linnavuori 1973, 1982), Indian species of Eysarcoris (Azim and Shafee 1984b), Indian species of
Hermolaus Distant (Azim and Shafee 1985), and Pseudolerida Schouteden (Linnavuori 1982).
2.2.10.7.23 Halyini Amyot and Serville, 1843
Amyot and Serville (1843) proposed this family-level name (as Halydes), and it has been recognized as
a valid tribe by nearly all subsequent workers. The real controversy concerning the taxonomic history
of this group is its composition. The reader will notice that many of the existing pentatomid tribes have
been associated at one time or another with the Halyini. This is a relatively large tribe containing 91
genera and 430 species (Table 2.3). Members of this tribe are extremely variable in size (8-35 mm) and
structure, making it rather difficult to characterize the group as a whole. In fact, Gross (1976) quoted a
colleague as saying ‘We all reckon we know whether a thing is a halyine or not, but what are really the
distinguishing characters of this group?’ They are medium to large in size, usually somewhat flattened or
depressed, and usually a mottled coloration of browns, grays, and pale areas (Figures 2.21J-L; 2.22A,
B; 2.30B, C). It is easy to envision most species occurring on the bark of trees, blending in with this
cryptic coloration. It is mostly an Old World group with only two genera (Brochymena [Figure 2.21K]
and Parabrochymena Larivière) known from the New World (Larivière 1992, 1994).
There is a tendency for the head to be long and slender (Figures 2.30B, C); the lateral margins of the
head and pronotum are often foliate or at least dentate or crenulate. Most genera have five-segmented
antennae, but a few have four segments (Neagenor Bergroth, some Poecilometis Dallas), and at least
one Australian genus has only three segments (Omyta). The rostrum reaches to the hind coxae, and
often beyond, well onto the abdominal venter. The scutellum is usually subtriangular in shape, although
in at least one genus (Mezessea Linnavuori) it is enlarged and spatulate-like. The legs and antennae
appear longer and more gracile than in members of other tribes. The femora may or may not be armed
with small teeth or spines; the outer surfaces of the tibiae are usually distinctly sulcate, and, occasion-
ally, the tibiae are dilated (e.g., Erthesina Spinola [Figure 2.21L]). The prosternum is usually weakly
sulcate, the mesosternum is medially carinate, and the metasternum is usually flat to shallowly concave.
In the New Guinean region, there is a group of genera (Accarana Distant, Auxentius Horváth, Babylas
Horváth, Brizica Wa l ker, Bromocoris Horváth, and Coctoteris Stål) in which the mesosternum may be
more or less sulcate, but there is still at least a weak medial carina; in these genera, the metasternum
is usually strongly sulcate, this sulcation continuing more or less onto the abdominal venter. Ectenus
Dallas and Epitoxicoris Wall appear to be intermediate between this group and the rest of the Halyini.
Also, the New World genera (Brochymena [Figure 2.21K] and Parabrochymena), and at least two Old
World genera (Mustha and Orthoschizops Spinola) have the sterna weakly to distinctly sulcate with the
medial carinae absent or obsolete; Mustha also has the margins of the head, pronotum, and abdomen
provided with a row of spines. Regardless of the above sternal structures, the abdomen may or may not
be sulcate; if sulcate, the sulcation may continue for most of the length of the abdominal venter or may
occur only on the base of the abdomen. The ostiolar rugae are quite variable, ranging from short to
long. The base of the abdominal venter is unarmed. Several genera (Atelocera Laporte [Figure 2.30C],
Carenoplistus Jakovlev, and Pseudatelus Linnavuori [Figure 2.22A]), in females, have the abdominal
venter nearly covered with two opaque spots (one on each side) with numerous hairs that seems to accu-
mulate waxy secretions (also seen in the Memmiini). The spermathecal bulb is ball-shaped with two
to three finger-like diverticula. For further discussion of various halyine characters, see Gross (1976),
Memon et al. (2011), and Kment (2013).
Due to the variability in structure, the Halyini has served as a dumping ground for many genera that
have been moved to other tribes (e.g., Agaeus, Agonoscelis, Phricodus Spinola, each now in its own tribe,
and, at one time, all of the taxa in the New World Ochlerini were included in the Halyini). Memon et al.
(2011) presented a phylogenetic analysis, based on morphology, of the South Asian halyine genera, and
although the methodology has been questioned (Barão et al. 2012), their results maintained that Agaeus
(Figure 2.28D) and Phricodus (Figure 2.31I) should be included in the Halyini. It should also be noted