Diversity of tortricid moths in apple orchards: evidence for a cryptic species ofGrapholita(Lepidoptera: Tortricidae) from China

Abstract

Understanding herbivore diversity both at the species and genetic levels is a key to effective pest management. We examined moth samples from multiple locations from a major apple growing region in China. For specimen collection, we used a pheromone trap designed to attract Grapholita molesta (Busck) (Lepidoptera: Tortricidae). Surprisingly, we found a second species captured at high proportions. Its external morphology (e.g., male genitalia and forewing coloration) was the same as for Grapholita funebrana Treitschke (Lepidoptera: Tortricidae) specimens from Europe. However, the barcode sequence of the mitochondrial gene cytochrome oxidase I (COI) diverged markedly between specimens from China and Europe, and the genetic distance value between the specimens from the two regions as estimated using the Juke-Cantor (JC) model amounted to 0.067. These morphological and molecular findings together point to a cryptic species in G. funebrana from China. Further molecular analyses based on COI and COII genes revealed its extremely high genetic diversity, indicating that the origin of this species includes the sampling region. Moreover, molecular data suggest that this species passed through a recent population expansion. This is the first report on a cryptic species in G. funebrana, as well as the first report on its genetic diversity.

The mitochondrial genomes of Tortricidae: nucleotide composition, gene variation and phylogenetic performance

“…In addition, Tortricidae is notable for containing numerous important pest species that cause large losses in crop and forest production [ 24 , 25 ], and many pest species (e.g., Grapholita spp.) are difficult to distinguish due to their morphological similarity [ 26 ]. Thus, in studies addressing species delimitation and the population genetics of these species, molecular markers have been traditionally employed [ 26 – 30 ].…”

“…are difficult to distinguish due to their morphological similarity [ 26 ]. Thus, in studies addressing species delimitation and the population genetics of these species, molecular markers have been traditionally employed [ 26 – 30 ]. Among these markers, however, only mitochondrial cox1 and cox2 are predominately used [ 26 – 30 ], indicating the necessity of screening potential marker candidates through sequencing more tortricid mitogenomes, especially in the context of increasing challenges with the standard cox1 barcoding marker [ 31 – 33 ].…”