Assessing Genetic Diversity in Four Stink Bug Species, Chinavia hilaris, Chlorochroa uhleri, Chlorochroa sayi, and Thyanta pallidovirens (Hemiptera: Pentatomidae), Using DNA Barcodes

Abstract

Stink bugs (Hemiptera: Pentatomidae) are an economically important group of insects that attack numerous crops in the central valley of California. Management of these pests using pheromones or biological control can be species specific, and proper identification of insect species is essential for effective management. The objective was to examine genetic variability in four species of stink bugs, which included Chinavia hilaris (Say) (= Acrosternum hilare) (Hemiptera: Pentatomidae) , Chlorochroa uhleri (Stål) (Hemiptera: Pentatomidae) , Chlorochroa sayi (Stål) (Hemiptera: Pentatomidae), and Thyanta pallidovirens (Stål) (Hemiptera: Pentatomidae) and to determine whether there may be cryptic species present. Stink bugs were collected in pistachios or on adjacent vegetation when abundant in the central valley of California. The mitochondrial DNA cytochrome oxidase I (COI) gene region (i.e., the barcode) was sequenced for each individual. Data were combined with available GenBank accessions for each species and used to construct a phylogenetic tree. Divergence between genera ranged from 11.2 to 15.7%, whereas divergence between the two Chlorochroa spp. was 4.6%. Genetic variation within Chinavia hilaris collections was up to 4.7%, which suggests the presence of a cryptic species. Genetic divergence was highest between individuals of Chinavia hilaris from the west coast and the east coast of the United States. In contrast, genetic variation within individuals of C. uhleri and Ch. sayi was less than 1%. Nine haplotypes were found for Chinavia hilaris, five for C. uhleri, three for Ch. sayi, and five for T. pallidovirens. The relevance of correct species identification and genetic diversity to stink bug management practices was discussed.

Keywords: DNA barcode; Stink bugs; cryptic species; genetic diversity; pistachio.