page_title: Thrips
section_title: Morphology
hierarchical_section_title: Thrips / Morphology
caption_attribution_description: Thrips schottii Heeger
context_page_description: Thrips are minute, slender insects with fringed wings and unique asymmetrical mouthparts. Different thrips species feed mostly on plants by puncturing and sucking up the contents, although a few are predators. Entomologists have described approximately 6,000 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, clap and fling, to create lift using an unsteady circulation pattern with transient vortices near the wings.
  Many thrips species are pests of commercially important crops. A few species serve as vectors for over 20 viruses that cause plant disease, especially the Tospoviruses. Some species of thrips are beneficial as pollinators or as predators of other insects or mites. In the right conditions, such as in greenhouses, many species can exponentially increase in population size and form large swarms because of a lack of natural predators coupled with their ability to reproduce asexually, making them an irritation to humans.
context_section_description: Thrips are small hemimetabolic insects with a distinctive cigar-shaped body plan. They are elongated with transversely constricted bodies. They range in size from 0.5 to 14 mm (0.02 to 0.55 in) in length for the larger predatory thrips, but most thrips are about 1 mm in length. Flight-capable thrips have two similar, strap-like pairs of wings with a fringe of bristles. The wings are folded back over the body at rest. Their legs usually end in two tarsal segments with a bladder-like structure known as an "arolium" at the pretarsus. This structure can be everted by means of hemolymph pressure, enabling the insect to walk on vertical surfaces. They have compound eyes consisting of a small number of ommatidia and three ocelli or simple eyes on the head.
  Thrips have asymmetrical mouthparts unique to the group. Unlike the Hemiptera (true bugs), the right mandible of thrips is reduced and vestigial – and in some species completely absent.
  The left mandible is used briefly to cut into the food plant; saliva is injected and the maxillary stylets, which form a tube, are then inserted and the semi-digested food pumped from ruptured cells. This process leaves cells destroyed or collapsed, and a distinctive silvery or bronze scarring on the surfaces of the stems or leaves where the thrips have fed.
  Thysanoptera is divided into two suborders, Terebrantia and Tubulifera; these can be distinguished by morphological, behavioral, and developmental characteristics. Tubulifera consists of a single family, Phlaeothripidae; members can be identified by their characteristic tube-shaped apical abdominal segment, egg-laying atop the surface of leaves, and three "pupal" stages. In the Phlaeothripidae, the males are often larger than females and a range of sizes may be found within a population. The largest recorded phlaeothripid species is about 14mm long. Females of the eight families of the Terebrantia all possess the eponymous saw-like (see terebra) ovipositor on the anteapical abdominal segment, lay eggs singly within plant tissue, and have two "pupal" stages. In most Terebrantia, the males are smaller than females. The family Uzelothripidae has a single species and it is unique in having a whip-like terminal antennal segment.
caption: Typical Tubulifera thrips: the feathery wings are unsuitable for the leading edge vortex flight of most other insects, but support clap and fling flight.
exif: {}