Observations sur la vie de Melanargia occitanica (Esper, 1793) de la Riviera franco-italienne, dans la nature et en élevage
The ecology and development of Melanargia occitanica (Esper, 1793) (ex-syllius) was studied in Mont Agel (Cote d'Azur, Alpes-Maritimes, France) in nature and in a glasshouse maintained on a terrace. Four females found at Mont Agel linked the species of the region to the graminaceous associations of Brachypodium rupestre. The females sought to lay their eggs on plants surrounding the holly oak (Quercus ilex). In the field, the female lays her eggs exclusively on the stems of Gramineae. The caterpillar hatches at the end of two weeks. After eating the eggshell, it begins a summer diapause during which only water is consumed. Feeding begins between mid-September and mid-October, and shedding occurs for the first time after three weeks. Subsequent sheddings take place at intervals of approximately 4 to 5 weeks; the last (L4/L5) taking place approximately two months before pupation (end of February- beginning of March). The caterpillars in stage LI were observed eating during the day, but fed exclusively at night during stages L4 and L5. In a parallel breeding experiment of M. occitanica conducted by L. Russo in Bari, Italy, the caterpillars fed at night at all stages. The first author was unable to breed until stage L5 with only one brown caterpillar. L. Russo bred 5 caterpillars until pupation who were green at L5, In stages L2-L4, the caterpillars of the first author were brown or green, those of Russo exclusively gree n 20 col.& b&w figs.