Morphological and Molecular Analysis of Parasitoid Wasp, Cheiropachus quadrum (Hymenoptera: Chalcidoidea: Pteromalidae) Infesting Bark Beetles of Wide Host Trees

Cheiropachus quadrum Fabricius, 1787 (Hymenoptera: Chalcidoidea: Pteromalidae) is a Pteromalid parasitoid wasp infesting wood boring beetles predominantly family Scolytidae. Owing to their profound diversity and small size, their identification is bit tricky. The present study involves molecular analysis and morphological identification including new host record, distribution and key identification characters of species. Morphologically, Cheiropachus quadrum is easily characterised by its large propleura, maculate forewings and enlarged fore-femur. Cytochrome Oxidase gene 1 was used as marker gene for DNA barcoding purposes. Sequences edited and trimmed in BioEdit were submitted to GenBank for accession number generation. BLAST and MEGA tools were used for molecular analysis to confirm the corresponding taxonomy. Generated sequence was found to have no perfect identity matches and hence was morphologically confirmed and submitted as novel sequence to the database. Molecular characterisation involving phylogenetic analysis was performed with top hits from blast database using Neighbour Joining and Maximum Likelihood tree construction methods. It was found that the mean A+T content is 74.19% and estimated Transition/Transversion bias (R) is 0.71. Among the COI sequences, we found no overlap between the maximum K2P distance within species (0.02%) and minimum distance between species (3.6%). Phylogenetic analysis concluded DNA barcoding is helpful for identification of parasitoid species and complements morphological taxonomy for easy identification purposes.