Thrips cause severe damage to many crops and are frequently found on imported crops.

Thus, many thrips species are categorized as quarantine pests. In this study, thrips species, intercepted in

imported agricultural products, were identified based on morphological characteristics and through

multiplex polymerase chain reaction (PCR). Five specific primers for the three quarantine thrips species

Anaphothrips obscurus (Müller), F. occidentalis Pergande, and Thrips fuscipennis Haliday and two

other common species, Thrips tabaci Lindeman and Frankliniella intonsa (Trybom), were

designed based on the internal transcribed spacer (ITS) region, a well-known marker for

species identification. Five species-specific primer pairs and one universal primer pair based

on conserved 28S ribosomal DNA were pooled in each multiplex PCR. Identification results

were consistent, whether based on morphological or molecular characteristics. Perhaps due

to the sample quality, the molecular identification efficiency was approximately 87%. The

most common thrips species on imported crops was T. tabaci, followed by F. occidentalis,

which was observed primarily on strawberry and artichoke crops from the United States;

some F. occidentalis specimens were also found on leucadendron and eryngium plants from

Australia and the Netherlands. The other thrips species found on imported crops were F.

intonsa, Scirtothrips dorsalis Hood, several species of the Tubulifera suborder, and one other

quarantine species, namely Thrips subnudula Karny, which was identified morphologically

on imported leacospemum plants from Australia. This study demonstrated that multiplex

PCR based on specific primers of the ITS region is a rapid and reliable method for identifying

quarantine F. occidentalis, which was identified with 93% accuracy. In addition,

morphological identification is crucial when nontarget quarantine thrips species are observed.