Revision of Mahea Distant, 1909, with a review of the Acanthosomatidae (Insecta: Heteroptera) of Madagascar and Seychelles
Author
Kment, Petr
) &) Department of Entomology, National Museum, Kunratice 1, CZ- 148 00 Praha 4, Czech Republic; e-mail: sigara @ post. cz &) &) Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ- 128 44 Praha 2, Czech Republic
text
Acta Entomologica Musei Nationalis Pragae
2005
suppl.
2005-12-31
45
21
50
journal article
8626
10.5281/zenodo.4476396
f638455f-2539-4bb0-816f-bafbc0b7c1ac
ISSN0374-1036
4476396
Mahea
Distant, 1909
Mahea
Distant, 1909: 32
, pl. 4 (description, figures).
Type
species:
Mahea sexualis
Distant, 1909
, by monotypy.
Muschalea
Cachan, 1952: 312
(description, figures).
Type
species:
Muschalea andriai
Cachan, 1952
, by original designation (syn.
KUMAR 1974
).
Mahea
:
KUMAR (1974)
: 43
-44 (diagnosis, taxonomy).
Redescription.
Body deltoid in shape; head shorter than pronotum; pronotum arched, sloping posteriad, highest between humeral angles, then descending caudad; dorsum flat; ventral side convex. Body surface slightly shining, covered with coarse dark punctures.
Head (
Fig. 1
). Mandibular plates sinuated in front of eyes, apically curved inwards, never spinously produced; clypeus with apex narrowly exposed or completely enclosed (intraspecific variable character). Eyes large, protruding from head outline by most of its width; ocelli situated behind imaginary line through posterior margins of eyes; each ocellus nearer to eye than to each other. Antenniferous tubercles visible from above; antennae 4-segmented (
Fig. 11
); antennomere 1 (scape) short, not or only very slightly surpassing apex of head; antennomere 2 (pedicel) very long, not subdivided, with erect pubescence; antennomeres 3 and 4 subequal in length, together about as long as antennomere 2, without erect pubescence. Bucculae low, diverging posteriad; maxillary plate tubercle developed; rostrum long, reaching or surpassing metacoxae; first rostral segment not surpassing posterior margin of eyes, hidden between bucculae.
Pronotum trapezoidal (
Fig. 28
); anterior margin more or less slightly concave, anterolateral angles touching posterior margins of eyes; antero-lateral margins rounded, more or less diverging posteriad; humeral angles always very prominent and spinuously produced (
Fig. 2
); posterior margin skewed posteriad to antero-lateral scutellar angles, margin anterior to scutellum concavely sinuate. Scutellum triangular, longer than clavi. Hemelytra narrow; clavi narrowly triangular (anteriorly with two rows of punctures, posteriorly with one row); corium long, triangular, acutely attenuated posteriorly and reaching middle of membrane, its posterior inner margin concave; suture between corium and membrane brown; membrane large, long oval, slightly brownish infuscated, translucent, slightly surpassing (exceptionally nearly surpassing) apices of postero-lateral angles of abdominal sternum 7 (
Fig. 14
).
Prosternum with deep median groove, flanked by longitudinal, prominently elevated carinae. Mesosternal carina flattened laterally, extending anteriorly between procoxae and reaching posterior margin of prosternal groove, posteriorly reaching between metacoxae. Metathoracic scent gland complex inconspicuous (
Fig. 31
); ostiole small, situated laterally between meso- and metacetabula; peritreme horizontal, slightly raised above metapleura, oval, shining; evaporatorium small, narrowly surrounding ostiole and peritreme. Metapleura swollen (
Fig. 14
) or not. Legs pale, ochraceous, with short to very short pubescence; femora twice as long as tibiae; tarsi 2-segmented; claws slender, long, straight, apically abruptly rectangularly curved; parempodia and pulvilli developed.
Abdomen with median carina well developed on sterna
3-6 in
males (
Fig. 4
) and on sterna
3-4 in
females (
Fig. 5
), produced anteriad as abdominal spine reaching between metacoxae, resting against mesosternal carina. Connexiva (especially its posterolateral corners) with more or less prominent spines (variable between species and sexes) (
Figs. 4-5, 14, 16
); especially postero-lateral angles of sternum
7 in
males conspicuously produced; sternum 8 slightly incised posteromedially.
Male genitalia. Pygophore subquadrate (
Figs. 7, 17
,
25
), more or less dorso-ventrally flattened (
Figs. 6, 16
,
24
); margins of external opening setose; dorso-lateral angles slightly produced, with tuft of conspicuous setae; proctiger large, convex, exposed; hypophyses of parameres exposed from pygophore (
Figs. 7, 17
,
25
); parameres flat, head enlarged, not bifurcate, bearing setae (
Figs. 18
,
26
); vesica of aedeagus long, deeply sinuated (
Fig. 19
) or looped (
Fig. 27
).
Sexual dimorphism strongly developed. Body of females behind humeral angles less narrowed; metapleura only slightly swollen; abdomen broader, median carina short, posterior part of abdomen flat; connexival spines with more than one spine per sternum, especially on sterna 5-7; Pendergrast’s organ not developed. Hind femora and tibiae are most probably sexually dimorphic in some/all species; I cannot confirm that given the lack of material.
Differential diagnosis.
According to
KUMAR (1974)
, the presence of both abdominal spine and mesosternal carina places
Mahea
as a member of the subfamily
Acanthosomatinae
. Within the
Acanthosomatinae
,
Mahea
and
Catadipson
are the only genera with 4-segmented antennae.
Catadipson
differs from
Mahea
in the following characters: elongate oval species; head very broad, slightly broader than two thirds of pronotal width; apex of clypeus free; mandibular plates projected as conspicuous apical spines; humeral angles of pronotum not produced, rounded; metathoracic scent gland complex as in
Fig. 32
; connexival margins without apparent spines; head and pronotum with very large black punctures.
Distribution.
This genus is known only from
Madagascar
(four species) and the
Seychelles
(Island of Mahé) (one species).
Comments.
KUMAR (1974)
noticed the resemblance in the descriptions of
Mahea
and
Muschalea
and considered them to be synonymous. He, however, did not examine Cachan’s
type
specimens of
Muschalea
. This synonymy is herein confirmed based on the study of
type
material.