Rise and fall of the thunderflies

Thrips (a.k.a. thunderflies) are minute slender piercing-sucking insects represented by over 5000 species in the order Thysanoptera. The western flower thrips, Frankliniella occidentalis, is a devastating pest insect on numerous crop species worldwide. Besides the direct damage inflicted by feeding on cell contents, they transmit pathogenic viruses leading to significant yield losses. Exploring and understanding the genetic basis of plant resistance mechanisms to thrips can greatly benefit the development of thrips-resistant crops. However, for the most part resistance mechanisms at the molecular level are still unclear. Screening plants for resistance to insects is generally a costly exercise in terms of space, time and labor. The need for efficient large-scale phenotyping systems is increasing now that next-generation sequencing has rendered a wealth of genomic information. Combining quantitative genetics with high-throughput phenotyping systems could reveal new genetic markers and genes that underlie thrips resistance in plants. Breeding for host plant resistance with the help of these markers may lead to a durable solution to F. occidentalis. This review will focus on the mechanisms that plants can use to chemically defend themselves against thrips, current methods of phenotyping for host plant resistance against thrips and the role of quantitative genetics in elucidating novel resistance mechanisms in natural plant populations