|
File: <pipun1.ima.htm> [For educational purposes only] Terminology Glossary <Principal Natural Enemy
Groups > <Citations> |
Immature
Stages of Pipunculidae
There were only two larval instars of A. spuria
recorded by Keilin & Thompson (1915a), the second having all the characteristics
of a normal 3rd instar cyclorrhaphous larva.
The first instar is 1.0 mm. long and a bit elongate. It bears a vesicle-like organ at the
posterior end of the body. The skin
bears neither sensory spines nor setae, and no tracheal system is distinguishable
until late in the stage when the lateral trunks fill with air. The second instar, or mature larva, is
robust and oval in outline, with the caudal vesicle still present although
reduced in size. The anterior
spiracles are elevated, and each has 4-5 openings. The posterior spiracles, each with three openings, are also
elevated and are situated at the lateral margins of a large, black, heavily
sclerotized peristigmatic plate. This
single plate, on which both spiracles are borne, is typical of the
family. Please
CLICK on
picture to view details:
In most cases the advanced 1st instar Ateleneura larva lies with its head directed toward the host's
thorax, but after the molt the position is reversed, the head being near the
tip of the abdomen and the caudal extremity at the juncture of the abdomen
and thorax. Parasitized leafhoppers
containing nearly mature Pipunculus
larvae may be easily recognized by the distended condition of the
abdomen. The larva emerges from the Typhlocyba nymph or adult
through an opening made between two segments of the abdomen and enters the
soil to pupate. In Pipunculus sp. the larvae were
always found by Perkins (1905e) to lie with the head directed frontwards, and
emergence was through an opening at the juncture of the thorax and
abdomen. In P. xanthocnemis
Perk, parasitic in Liburnia,
the emergence hole is in the mid-dorsal abdominal area. The mature larvae of P. annulifemur
Brun. can jump similar to fruit fly larvae (Subramaniam 1922). Although most species pupate in soil, some
like P. cinerascens Perk. form puparia on foliage. The larva of P. xanthocerus
Kow. differs in having the integument heavily spinose rather than smooth, a
trait that persists in the puparium. Puparia of Pipunculidae are broadly oblong in outline, often with
a granular or rugulose sculpturing, and are red, black or brown in
color. The prothoracic cornicles are
very small in some species, and can barely be seen projecting through the
puparial wall. In other species, such
as P. cinerascens, they are borne at the apices of very large
conical processes. The posterior
stigmatic area is rounded in some species and depressed in others, with the
spiracles borne at the lateral margins.
Each spiracles usually has three openings, although there may be two
in some species and in others only one.
The entire anterior portion of the puparium is completely or partly
forced off in two parts, the dorsal one usually bearing the prothoracic
cornicles, at eclosion. The
transverse line of fracture is just behind the anterior margin of the 2nd
abdominal segment (Clausen 1940/62).
In Chalarus and Verallia, there is a
modification in the manner of emergence from the puparium. The two anterior plates, which are forced
off, are broken further, the upper one into three parts and the lower into
two (Lundbeck 1922). In this way five
pieces are detached from the puparium compared to only two in Pipunculus. The prothoracic cornicles occur along the
line of fracture and are not a part of the median dorsal plate. The relation between the five parts and
the lines of fracture were shown by De Meijere (1917) for an undetermined
species. Swezey (1936) reported on the duration of the life cycle for
several species of Pipunculus. The combined egg and larval stages last 40
days and the pupal stage about one month.
The pupal stage is completed in 14-19 days in P. annulifemur. References: Please refer to <biology.ref.htm> [Additional references may be found at: MELVYL Library] |
