Molecular identification key for Scirtothrips pest species
The genus Scirtothrips (Thysanoptera: Thripidae) includes 100 species of which approximately 10 are recognized as plant pests attacking, for example, avocado (Persea americana), citrus, mango (Mangifera indica), tea (Camellia sinensis). Species identification is difficult because it requires expert knowledge and is almost impossible without the presence of adult specimens. In order to provide an easy, accurate and highly reliable identification technique, a simple molecular key based on the internal transcribed spacer regions (ITS1 and ITS2) of nuclear ribosomal DNA was developed in California (US). Multiplex PCR followed by restriction of PCR products provided a set of simple diagnostic characters for several Scirtothrips species including for example, S. aurantii (EPPO A1 list), S. citri (EPPO A1 list), S. dorsalis (EPPO A2 list), and S. perseae (EPPO Alert List). However, the authors recognize that the genus still needs to be identified with morphological methods. During this study, molecular data suggested that the species complex from avocados proposed by other authors was actually a single species (S. perseae), but that Indian and South American specimens of S. dorsalis should be considered as separate species. Finally, some other Scirtothrips species (S. bispinosus, S. longipennis, S. mangiferae and S. manihoti) still need to be further studied to be incorporated into the key.
Rugman-Jones PF, Hoddle MS, Mound LA, Southamer R (2006) Molecular identification key for pest species of Scirtothrips (Thysanoptera: Thripidae). Journal of Economic Entomology 99(5), 1813-1819.