A Simple and Rapid Molecular Method for Simultaneous Identification of Four Economically Important Thrips Species

Quick and authentic identification of exotic and potentially invasive taxa with capability of causing high economic losses or detriments is essential prerequisite for effective plant quarantine and biological control initiatives. The order Thysanoptera includes several agricultural pest species that, not only because of their minute size but also due to their cryptic behavior, incline to undetected transport through international trade of plants. Identification of thrips, particularly at species level, is pretty demanding and requires expertise in knowledge about Thysanoptera. Moreover, in most cases, identification of larval Thysanoptera to species is impossible without presence of adults. Hence, there is a great desire for a facile, accurate, and highly reliable technique for thrips identification. The present study describes species-specific primers for four pest thrips species, and the use of a multiplex PCR assay to detect and to distinguish between the four target species. Five primers were used to simultaneously amplify a specific region of the mitochondrial DNA and produce species-specific fragments. Results indicated that the primers were capable of detecting these four species and amplifying uniquely sized, species-specific PCR products. Furthermore, using a multiplex PCR assay, the primers maintained specificity and sensitivity, and allowed detection of each of the four species in a single reaction. The stringency of the method was tested using specimens of different developmental stages and consistent results were obtained for all of the examined samples. This method is simple enough to be implemented by non-experts and also can be extended to any organism for which quick and reliable identification is needed.