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The
HEAD is hypognathous, so the buccal apparatus
is turned downwards. Two composed eyes and three
simple ocelli are present, on the vertex. The
space between the base of the eyes and the articulation
of the jaws is the malar space, of taxonomic
importance. The antennae are inserted little
above the jaws, in correspondence of the upper part
of the clypeus: here are the scape, the pedicel
and 11 flagellomeres, generally cylindrical.
The relative length of the first 3 flagellomeres is
of diagnostic importance. The clypeus is generally
short and wide, except for the Stilbum Genus.
The jaws are simple and are armed with 0-3 apical
teeth. The central part of the face is occupied by a
depression (scapal basin) able to receive the
antennas in a folded position. The upper part of the
face is the forehead, often characterized by
a crossing carina projecting behind to the area of the
ocelli (vertex).
The
THORAX is subdivided into 5 articulate segments:
pronoto, mesonotum (scutum), scutellum, metanotum (postscutellum)
and propodaeum. The surficial sculpture can be absent
(smooth teguments) or intense (punctuation, drills,
carinas). To the pronotum, comprising the neck,
articulates the first pair of legs. The mesonotum
(scutum) is characterized by 3 regions (two lateral
and one central = mesoscutum or medium mesonotum separated
by notauli and laterally by the 2 tegulae
that cover the wing articulation. The scutellum
is generally shorter than the scutum. The metanotum
can be characterized by a projection (Elampus,
Parnopes), or can be fused with the propodaeum;
it is often characterized by the presence of lateral
metathoracic teeth. The propodaeum, precisely
the first gastral segment, is generally vertical and
lacks an upper flat face; it's also characterized by
two lateral teeth. The legs are generally adapted
for an excavating activity. The segments that compose
the legs are the hip (coxa), the femur, the tibia and
the tarsus. The terminal part of the tarsus is armed
with dentate nails.
The
ABDOMEN shows a combination of external and internal
segments. Amiseginae, Cleptinae and Loboscelidiinae
have 5 external abdominal segments in males and 4 in
females, the Parnopinae have 4 in males and 3
in females, the Allocoeliini 2 tergites (dorsal
segments) and 3 sternites (ventral segments) in both
sexes. In the other tribes males and females have 3
abdominal segments. The external segments are generally
very sclerotized and concave in the ventral side, except
for Cleptinae, Amiseginae and Loboscelidiinae,
where the sternites are convex. A useful diagnostic
structure is found in the anal edge of the last tergite,
characterized by teeth, carinas, projections and spots.
Above the anal edge a characteristic pit row is often
present. The internal abdominal segments form a subcylindric
telescopic tube, introflected during the rest, representing
the female's ovipositor and the male's genital tube.
The sting sensu strictu is reduced and doesn't work.
In males, at the end of the tube a genital capsula is
present, standing on the eighth sternite, both structures
of diagnostic importance.
In
modern hymenopterological nomenclature the terms mesosoma
and metasoma are used instead of thorax and abdome,
respectively. The reason is that the first abdominal
segment (propodeum) is joint with the morphological
thorax and the famous "wasp-waist" articulates
two abdominal segments and not the thorax to the abdomen.
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body in lateral view and
internal abdominal
segments
(from
Kimsey & Bohart, 1991)
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All
the micrographs were taken with a JEOL JSM-5400 Scanning
Electron Microscope, after a vacuum ionization of the
dried specimen (Chrysis scutellaris) with gold
(JVG-N1 Gauge and JEE-4B Evaporator).
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