Molecular demography of the green-belly stink bugs Diceraeus spp. (Hemiptera: Pentatomidae): Potential invasive pests to the Americas

The green-belly stink bugs Diceraeus spp. (Heteroptera: Pentatomidae) are considered emergent pests in different cultivated plants in Brazil. The species Diceraeus furcatus (Fabricius) and Diceraeus melacanthus Dallas are morphologically similar and their recognition is still hard for non-specialists. Based on wide sampling throughout the distribution of Diceraeus spp. in Brazil, the objectives of the work were to study the molecular diversity of populations of both species and define a molecular marker for its identification. DNA from individuals was extracted and mitochondrial genes (COI and 16s) were amplified and sequenced. D. melacanthus has high nucleotide and haplotype diversity for both genes in the Southeast and the Cerrado regions, and also in the South for the 16S. D. furcatus has the highest values of nucleotide diversity in the Cerrado. Based on the values of the fixation index, we observed a high structure of populations of both species, D. melacanthus (ΦST = 0.32) and D. furcatus (ΦST = 0.23). We estimated that divergence time of species occurred during the Plio-Pleistocene. A restriction endonuclease was designed to identify the species. The enzyme digest of the 701bp COI PCR product generated two bands of 451bp and 250bp in D. melacanthus, while in D. furcatus only a single band of 701bp.