Thrips. Coloured scanning electron micrograph (SEM) of a thrips, or thunder fly (order Thysanoptera), feeding inside a grass seed head. Thrips are small, sap feeding flies that are characterised by the fringes of long hairs on their wings (upper left). Thrips feed on sap by piercing plant cells with their paired maxillary stylets (seen below the first pair of legs at upper right), which form a feeding tube. A compound eye (brown) and a pair of short antennae are also seen. Thrips are pests of commercial crops due to the damage caused by feeding on developing flowers or vegetables. This causes discolouration and deformities, reducing the quality of the crop. They are also considered the primary vector of plant diseases and viruses.