The evaluation of matrilineal admixtures in “Cerambyx spp.” with opposite protection statuses “Cerambyx Cerdo (protected) and Cerambyx welensii (unprotected pest)” highlights the conflicting nature of the management of these insects in the UNESCO pro

Abstract The immense biodiversity of the Mediterranean forest, the Iberian dehesa , is being damaged by different invasive or native animal species. This fact is currently associated to climate change and/or human activity, as it also happens in other areas of the planet. This study highlights this key issue based on the protected Cerambyx cerdo and the invasive Cerambyx wellensii , both feeding on the live wood of Quercus spp. trees which populate the dehesa . The possible biological damage which these insects are creating is not presented as evident, but the worrying effects faced by this protected ecosystem are pointed out. This study focuses on the demand for genetic data analysis from Cerambycids inhabiting the dehesa and it also aims to reveal the relationship between both native and invasive Cerambyx species by using a small-scale survey. The existing genetic diversity, Adult’s Sex-ratio (ASR), Sexual size dimorphism (SSD) and Spatial Analysis of Molecular Variance (SAMOVA), suggested the competition and/or hybridisation of these two species until the depletion to possible extinction of the authentic Cerambyx cerdo (the biological jewel of this forest). Accordingly, C. cerdo has begun to conform a “ Cerambyx spp. complex” at the expense of the demographic expansion of Cerambyx welensii coupled with the progressive reduction of its own lineages.