File: <chalc1.ima.htm> [For educational purposes only] Terminology Glossary <Principal Natural
Enemy Groups > <Citations> |
Immature Stages
of Chalcididae
Immature stages of Chalcididae were discussed in detail
by Clausen (1940), as follows: The eggs of the majority of
species of the family are elongated and broadest at the anterior end, with
both ends smoothly rounded, and the length is four to six times tho maximum
width. A small, slightly roughened
area represents the micropylar area.
In B. fonscolombei (Fig. 102B), there
is a distinct slender peduncle, somewhat distended at the tip, at the
anterior end. The egg of B. compsilurae (Fig. 102A) is distinguished by the possession
of a membranous envelope which conforms to the shape of the egg body but is
considerably larger, and the anterior end bears a roughened micropylar area
similar to that of the egg proper (Dowden, 1935). The first‑instar larvae are
of two types, the hymenopteriform and the caudate. The first‑named is found in the ectoparasitic species and
in those which are endoparasitic in lepidopterous pupae, and the caudate
larva occurs among the species that develop in dipterous pupae. The hymenopteriform larva of B. intermedia,
which is characteristic of that type, is somewhat elongate, with a large,
lightly sclerotized head and 13 distinct body segments of approximately equal
length, each of which, except the last, bears three pairs of sensory setae
and numerous cuticular spines, particularly on the venter. There are four pairs of spiracles,
situated on the second thoracic and the first three abdominal segments. B.
femorala and E. caryobori are said to have only two pairs of sensory setae
on each segment. Please CLICK on picture to view details: The caudate first‑instar
larva, represented by B. compsilurae and B. fonscolombei (Fig. 102C, D) has 11-12 distinct body
segments followed by a tail representing one‑fifth to one‑third
of the total length. In B. fonscolombei, the tail apparently represents the fused
twelfth and thirteenth segments.
There appear to be no sensory setae; but each segment bears a partial
or complete ring of cuticular spines, and these occur also upon the tail,
though irregularly distributed. An
internal tracheal system is present, but there are no spiracles. The second‑instar larva is
more robust, and, in the caudate form, the tail persists, though reduced in
size. There appears to be no
uniformity in spiracle number or arrangement. B. compsilurae still has none; B. intermedia retains the four pairs present in the first
instar, of which those on the mesothorax are much the largest; and B. fonscolombei (Fig. 102E), B. femorata,
and E. caryobori
have nine pairs, situated on the second and third thoracic and the first
seven abdominal segments. The third‑instar larvae show
a further convergence of the two forms.
In B. compilurae, the sensory setae
first appear at this time. All
species have the nine pairs of spiracles arranged as given above. The fourth‑instar larva presents no
distinctive features. The fifth‑instar larvae of Brachymeria and Euchalcidia are oval in
outline, distinctly segmented, and yellowish‑white in color. They bear no cuticular spines, but the
sensory setae are present though minute.
B. fonscolombei (Fig. 102F) and B. compsilurae
parasitic in dipterous puparia and having caudate first‑instar larvae,
are further distinguished from others of the family by the possession, in the
mature larva, of yellowish, wedge‑shaped sclerotized plates situated
just below the spiracles of the second to seventh abdominal segments. The function of these is unknown. The spiracles are as in the preceding two
instars. References: Please refer to <biology.ref.htm>,
[Additional references may be
found at: MELVYL Library ] |