File: <peril1.ima.htm> [For educational purposes only] Terminology Glossary <Principal Natural
Enemy Groups > <Citations> |
Immature Stages of Perilampidae
Immature stages of Perilampidae were discussed in detail by
Clausen (1940), as follows: The egg of P. chrysopae (Fig. 93) is
subcylindrical and distinctly arched on one side with one end rather sharply
pointed and the other bearing a short, broad peduncle. It is pearly‑white in color, and the
chorion is characteristically sculptured, with irregular elongated areas that
extend lengthwise. The eggs of P. tristis (Fig.
93) and P. italicus are very similar. The size of these eggs, which measure 0.25
mm. in length in P. chrysopae and 0.41 mm. in P. italicus, contrasts strongly with the very minute stalked
eggs of the related Eucharidae. The first‑instar larvae of Perilampus are all of the planidium type, with heavy
segmental bands that almost reach the median ventral line. There are 13 body segments, of which the
first 12 bear the sclerotized bands and the 13th is represented by the caudal
sucker. Specific differences occur in
the form of the terminal portions of the bands and in the number, size, and
position of the body spines and the "scales" and hooks on the
membrane of the venter of the anterior portion of the body. The pleural plates, which have been
distinguished upon the planidia of the Eucharidae and of families of other
orders having larvae of this type, are absent or not recognizable. Please CLICK on pictures to view details: On the larvae of P.
hyalinus (Fig. 94A) and
several others, the posterior margins of the terminal portions of each band
bear numerous sharp teeth, whereas in P.
chrysopae (Fig. 94B) they
are smooth. The sensory spines are
exceptionally long and heavy in the latter species. The two caudal cerci arise dorsolaterally from the last
segmental band. In Perilampus sp. from Conocephalus (Ford 1922), they
are about 1/2 the length of the body. Spiracles have been detected in P. hyalinus,
P. chrysopae, P. tristis,
and several undetermined species; all these except the first have a single
pair dorsolaterally at the anterior margin of the band of the second thoracic
segment or on the membrane between the first and second segments. In P.
hyaiinus, the spiracles are
on the intersegmental membrane but distinctly ventral. The number of larval instars is uncertain. Smith recognized only three in P .hyalinus, while Parker described four for the same species
and Bergold & Ripper found the same number in P. tristis. The second‑instar larva of P. hyalinus
(Fig. 95B) lacks the specialized characters of the first instar, and the body
is white and distinctly segmented.
The sensory setae are small and set upon tubercles, and each segment bears
a band of minute integumentary setae at the anterior margin. The two pairs of large spiracles are
situated on the mesothorax and the first abdominal segment. The larva of P. chrysopae
(Fig. 95A) is similar, though more robust, but in P. tristis
the spiracles are said to be on the pro- and metathorax. The third‑instar larva of P. hyalinus
(Fig. 95C) is rather indistinctly segmented but still bears the sensory and
integumentary setae mentioned for the second instar. There are now seven pairs of spiracles,
situated on the last two thoracic and the first five abdominal segments, of
which the first and third are largest.
In P. tristis, the number and
position are the same. The fourth‑instar larva of P. hyalinus (Fig. 95D), which is
the mature form, is distinctive, being very robust and bent ventrally in the
thoracic region, with large lateral segmental "bosses" on the first
5 abdominal segments and distinct fleshy tubercles of testaceous color at the
lateral margins of the second and third thoracic segments. The sensory and integumentary setae of the
preceding instars persist. There are
nine pairs of spiracles, the additional two pairs being on the sixth and
seventh abdominal segments. The larva
of P. tristis is similar except that the thoracic tubercles
occur on all three segments. The pupae of the different species are short and robust, with the
abdomen almost spherical and bearing transverse intersegmental welts similar
to those of some Eucharidae. References: Please refer to <biology.ref.htm>, [Additional references may
be found at: MELVYL Library ] |