Published on Monday, 03 December 2012 21:00
Written by Super User
This stage of development pre-imaginal begins with the tearing of the larval cuticle along the dorsal midline in the cervix-notal region, it swells due to the increased influx of hemolymph in this region (Casale et al., 1982). From this tear comes out the pronotum of the pupa, followed by the head and abdomen. What remains of the larval cuticle accumulates in the bottom of the cell.
From a purely morphological point of view, the nymph has larval and imaginal characters at the same time that (Casale et al., 1982). In addition, this stage of development is easily recognizable by the intense sweet odor that emanates.
The pupal stage has a duration about 15-20 days after which begins the ecdisi process that leads to the complete exit (emerging from the cocoon) of the adult.
Emerging from the cocoon and Cromatogenesi of the Imago- The emerging from the cocoonprocess of imago occurs due to the increase in volume of the cervical region notale, due to a greater flow of hemolymph and air, followed by the tearing of the nymphal cuticle resulting in the leakage of pronotum, head and the upper part of the elytra. This phase has a total duration of about 25 minutes. In this period of time also takes place "coaptation elitrale", which, according Fiori (1974) can be, depending on the species, of "temporary" type or of "permanent" type with a defined "dovetail" interlocking (Casale et al., 1982).
The emerged adult has a mushy texture and a whitish color with some region of the body pigmented (ocelli, mandibular end, end of the first four articles of the antennae, nails, knees, shins, hair and side lobes of urotergiti). A first pigmentation is due to the progressive sclerification animal's body followed by active synthesis of melanin. These colors are called "chemical or pigmental" In some Carabidae beetles (for example Carabus olympiae, Carabus intricatus, Carabus auronitens) is added the type "physical or structural" color. In this case, the bright metallic colors are derived from an optical phenomena (refraction, reflection, scattering, interference and absorption of light) determined by the particular structure of the epicuticola.
The complete process of adjustment of the image (cromatogenesi) occurs in approximately 24-48 hours depending on the weather conditions (temperature, humidity, etc..). Sometimes even small environmental changes can generate cromotipi extremely special and rare. It 'a known case in the species Carabus olympiae, the exceptional chromatic aberration "fucatus" characterized by nuances of yellow and red.