DNA barcoding reveals the occurrence of cryptic species in host-associated population of Conogethes punctiferalis (Lepidoptera: Crambidae)

Conogethes punctiferalis (Guénee) is a critical pest that commonly infests castor (Ricinus communis Linnaeus) and cardamom (Elettaria cardamomum Maton) in India. The moths of both castor and cardamom appear to be similar in wing pattern and color. However, the results of behavioral studies elicited a doubt that there may be differences in terms of host specialization. In the present study, we conducted morphological studies and DNA barcode analyses using cytochrome oxidase I gene, which unraveled the mystery of C. punctiferalis breeding on castor and cardamom. The differences in male aedeagus and female bursae were prominent, yet, not sufficient enough to say that they are different species. The results showed high haplotype diversity (0.817 ± 0.073) and nucleotide diversity (0.0285 ± 0.002) in C. punctiferalis. In addition, topologies of neighbor-joining trees indicate that Conogethes sp. breeding on castor belongs to C. punctiferalis while those on cardamom are of a separate clade. Further genetic analysis revealed significant genetic differentiations among the two sampled populations, reflecting limited gene flow. Neutrality tests and mismatch distributions showed population expansion in C. punctiferalis, while the results of an analysis of molecular variance (AMOVA) indicated the existence of significant genetic variation among the examined host races. Conclusively, analysis using mitochondrial DNA showed an amount of genetic divergence between the two host-associated populations compatible with cryptic species rather than host races.