Mating and oviposition

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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.