Identification at the larval stage of four Curculio species coexisting on oak trees using PCR‐RFLP

Several species in the family Cecidomyiidae (Diptera) are known by a particular reproduction mechanism called monogeny, in which all offspring of each individual female are either exclusively male or exclusively female. As a consequence, no full‐sib mating occurs in monogenous populations. So offspring of each female must inevitably mate with those of other females, and in the worst condition, mating may occur between individuals with a common sire but different mothers, where they are only half siblings. Simulation of monogenous gall midge pedigrees, calculation of inbreeding coefficients of individuals for 20 generations, and comparing the results with those of a non‐monogenous species revealed that the total average inbreeding coefficients of individuals were not dramatically different between these two populations. However, the maximum inbreeding coefficient of individuals per generation in non‐monogenous populations was significantly higher than in monogenous populations. Despite the effect of monogeny on inbreeding, it is doubted whether inbreeding avoidance is the only force that drives the evolution of monogeny in gall midges.