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Pupating and emerging from the cocoon



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.

Larvae development

After hatching, the larva remains within its own cell for a few days. In this days it gradually completes the process of pigmentation, from white to gray until the complete melanization. The first portion of the body that changes of color is the abdomen followed by legs, head, antennae and prothorax (Sturani, 1947). The larvae develop through three larval stages (defined by the letters L1, L2, L3); they are of type campodeiform with the head with a square shape, devoid of the region of the neck, and the body rather narrow and elongated with urogonfi seats at the rear end of the abdomen. After the first two or three days of inactive life inside the cell, the larva in the first stage (L1) starts to move actively in search of prey, mainly consisting of small gastropods and arthropods alive. Unlike adults, mainly polyphagous, the larvae are very demanding with regard to the feeding. After the first larval stage, which typically lasts 12 days, takes place the first moult. This process occurs in ground sheltered areas, or below stones of an medium size. The second-stage larva (L2) behaves essentially as in the previous case, but due to its increased size it can feed on a wider range of prey. After about 11 days takes place the second and final moult. At this point the larva of the third stage (L3) will continue to grow to reach the size of 34 mm after about 13 days. Similarly to adults all larval stages are active during the night, especially after sunset and into the morning. During the day they take refuge under the litter or below the stones in order to avoid excessive exposure to sunlight which would entail the death by dehydration. At the end of the third larval stage (L3) the larva begins to dig into the ground a cell for pupation in a depth of about 10-30 cm. After a few days the preparation of the cell is completed; compared to those of the larva, it has a larger size (55 X 40 X 28 mm). At this point, if the environmental conditions (T, humidity, etc..) are favorable the animal locates supine in the cell and begins the process of pupation. It is common, due to a particularly adverse weather conditions, or in response to a late ovideposiziopne that the larvae reach maturity very late (late August, early September). In these circumstances the L3 stage does not come to pupation, but enter into quiescence (diapause larvae) until the beginning of next spring. It 'obvious that in this case the biological cycle will not be annual, it will be biennial, due to the adults of these larvae of "long cycle" will appear only the following summer. This phenomenon has a clear adaptive significance, to prevent pupation in times inadequate for the third-stage larvae that have had a late development.

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Mating and oviposition

The coupling of Carabus olympiae usually occursbetween spring and summer, from late June to early July. At this stage subjects of the opposite sex meet thanks to particular pheromonal emissions that facilitate the approach and recognition. It is often seen that couples tend to repeatedly raise and lower the elytra in a sort of pre-coupling courtship. This phenomenon was observed for the first time by Sturani (1947) in this species, but subsequently has been described in other taxa.


It's important to note that the movement of the elytra is not essential for the success of the coupling, as experienced in farms conducted in laboratory (Malausa, 1978). Moreover subjects close to coupling tend to emit aromatic secreted very similar to those produced during the pupal stage (Casale et al, 1982).

The copula, which takes place from behind, as in all other species of Carabidae, usually lasts 50 minutes (Sturani, 1947) and the adhesion of the male to the female is facilitated by the expansion of the last tarsomeres with adhesives pulvilla.


The deposition occurs later, usually after the female is fed. The female, characterized by a visibly swollen abdomen, usually digs a cell (2 cm deep with the size of 6.5 * 2.5 mm) at the beginning using its strong mandibles and subsequently by its two gonapophysis in the terminal part of the abdomen. Once the excavation is done it lays a single egg, because unlike many other species that produce more eggs within the same cell, the species Carabus olympiae it lays only one for each cell dug into the ground. After this stage, the female closes the cells with the excavated soil.

The entire period of oviposition can last more than a month with an average number of eggs laid around thirty units; the latest deposited are often infertile or give rise to abnormal larvae that are not able to complete the development cycle. This phenomenon according Malausa (1978) is related to the depletion of sperm accumulated along the genital tract of the female during mating late spring.


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Carabus olympiae, steno-endemic species of Val Sessera, lives in a very small area within forest habitats. In the last century the species was threatened with extinction by collectors, but thanks to the characteristics of the habitat in which they live, that can provide shelter and food, this insect was able to overcome the phases of the population regression.



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