Submitted to: Applied Entomology and Zoology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/18/2014
Publication Date: 5/27/2014
Citation: Kumar, V., Seal, D.R., Osborne, L., McKenzie, C.L. 2014. Coupling scanning electron microscopy with DNA bar coding: A novel approach for thrips identification. Applied Entomology and Zoology. 49:403-409 Interpretive Summary: Chilli thrips is an emerging pest of many economically important vegetable and ornamental crops grown in the United States. The small size and cryptic nature of this pest make their identification difficult. Traditional taxonomy involves slide mounting specimens for morphological identification, but this is often time consuming, labor intensive, requires expertise, and also involves the risk of specimen collapse and disintegration. We were able to couple morphological and molecular identification techniques to develop a quick, reliable and simple diagnostic method that uses the same specimen resulting in verification of both identification techniques simultaneously.
Technical Abstract: The small size and cryptic nature of thrips pests help them acquire microhabitats of a plant and in the field, often making their monitoring and the identification process difficult. Accurate identification of such pests is a fundamental requirement in development of any effective quarantine and management strategies. Thus, with the aim to obtain accurate identification of various pest species in the order Thysanoptera, a preliminary study was conducted on Scirtothrips dorsalis Hood specimens. We coupled morphological and molecular identification techniques to develop a quick, reliable and simple diagnostic method. Prior to the DNA extraction of S. dorsalis specimens, larvae and adults were subjected to traditional morphological identification using high resolution scanning electron microscopy (SEM) and then gold/palladium sputter coated thrips specimens were processed for Polymerase chain reaction (PCR) assay for molecular identification. Sequence results of both mtCO1 and ITS rDNA of individual larva and adult S. dorsalis were in agreement with the taxonomic identification conducted using SEM and each result confirmed the other technique. In the past, thrips specimens had to be slide mounted for morphological identification and were destroyed or rendered unusable for DNA analysis. Our results suggest that the two techniques together could be used for the correct identification of various thrips species using a single specimen.