located on the sides of the mouth opening, immediately below the upper labrum

forms the upper part of the mouth opening

larvae have an annual duration or a biennial cycle, where the larval development period can exceed twelve months.

adults reproduce in spring or summer. Larvae grow rapidly and are strictly temperature-dependent, without dormancy. Development is often very fast (a few weeks). This reproductive adaptation can essentially be defined as "opportunistic."

adults reproduce from late summer to late autumn, and in some cases, early winter. Larvae develop more slowly and are dependent on an obligatory dormancy that requires a drop in temperature to proceed. Development can thus last 8–9 months.