Thrips (order Thysanoptera)

InsectTinyPlant-feeder

Overview

Thrips (order Thysanoptera) are minuscule, slender insects — most less than a couple of millimetres long — that are easy to miss yet enormously numerous, often found tucked inside flowers, on leaves, and among buds. Despite their tiny size, they have a remarkable signature feature: their wings (when present) are narrow straps fringed with long hairs, like tiny feathers, which is what the order's name (Thysanoptera, “fringe-wing”) refers to. A quirk of the word: “thrips” is both singular and plural — one is a thrips, many are thrips (never a “thrip”).

Thrips have unusual, asymmetrical mouthparts that they use to puncture and rasp plant (or fungal) cells and suck out the contents, and they include both significant crop pests and useful pollinators.

Note: “thrips” covers a large order; details here describe the group broadly. Treat general statements as approximate and verify against authoritative sources.

Habitat & Range

Thrips are found worldwide wherever plants grow — in flowers, on leaves and buds, in leaf litter, on fungi, and in grasslands, forests, farmland, gardens, and greenhouses. Many shelter in tight spaces such as the insides of flowers and leaf folds, and different species specialise on different plants or feed on fungal spores and other small organisms.

Diet

Most thrips feed on plants, using their single functional stylet and rasping mouthparts to pierce individual cells of leaves, flowers, and developing fruit and suck out the contents, which can scar and distort the plant. Others feed on fungal spores or pollen, and a number of thrips are predators that hunt mites and other tiny thrips. By moving among flowers and carrying pollen, some thrips also act as pollinators of certain plants.

Behavior

Thrips are weak fliers, but their fringed wings let them stay airborne in air currents, and huge numbers can be carried on the wind (they sometimes appear as the tiny “thunderbugs” or “thunderflies” noticed on warm, still days). They have an unusual life cycle that is neither fully gradual nor a true complete metamorphosis: after feeding nymph stages, they pass through quiescent “pupa-like” stages before becoming winged adults. Many reproduce rapidly, and some can reproduce without mating, so populations build quickly. A number of thrips transmit plant viruses as they feed, which can make them serious agricultural pests beyond the direct feeding damage; a few species, however, are reared as beneficial predators or valued for pollination.

Human Interaction & Conservation

Thrips matter to people mainly through agriculture and gardening: several species are major pests of crops, flowers, and greenhouse plants, both by feeding and by spreading plant viruses, and they are a frequent focus of pest management. Yet thrips are also part of healthy ecosystems — pollinating some plants, recycling fungal and plant material, and serving as food for other small creatures — and predatory thrips help control mites and other pests. They are harmless to people (though large swarms can be a minor nuisance). Consult authoritative sources for details on specific species.

More photos of the thrips