Class: Insects
Size: 1 to 3mm
Weight: Variable
Age: Unknown
Appearance: Yellow to black colouration, wings with fringed hairs
Food: Plants, fungi, mites, scale insects
Distribution: Worldwide, 5’500 species, of which approx. 400 in Europe
Original location: Unknown
Sleep-wake rhythm: Diurnal
Habitat: Open field, garden, vegetable plantations, houseplants
Natural enemies: Lacewings, predatory mites
Threatened with extinction: No

• Due to their low weight, fringe winged insects glide with the wind as “air plankton” for several hundred to a thousand kilometres and are therefore found everywhere in the world, except in the polar regions. Another factor is also the worldwide trade in plants, through which many species of fringe-winged thrips still spread widely today. However, the main focus of their distribution is still in the tropics, because many species are bound to specific host plants.
• Fritillary infestations show up in small black dung heaps and sucking spots with needle-like yellowish mottling which later turns silvery white due to oxidation. The elongated cream-coloured larvae or the adults on the plant are hardly visible to the naked eye.
• Some species feed only on the outer layers of the leaf, the so-called epidermis, and the underlying mesophyll. By piercing the individual cells, they can suck out the fluid. The affected cells then become shiny silvery and bright. The damage is thus similar to that of spider mites. Some species inject plant galls, inside which they then live and feed. Some species attack only specific plants, others a wide range of different host plants. Other species are flower visitors and therefore feed on pollen.
• Thrips cause visible damage to plants and fruits and are therefore classified as pests and controlled. Especially Scirtothrips dorsalis and Heliothrips haemorrhoidalis are among the most feared pests in subtropical and tropical countries. Especially the optical defects on fruits or leaves (of ornamental plants) can strongly reduce the commercial value.
• The name “fringe winged insects” comes from their long hair fringes on the edges of their wings. The name “bladder feet” comes from structures on the feet (called arolium), which are bulged out like balloons when pressure is increased, and are wetted with fluid by a gland. They serve to adhere to smooth surfaces.