Adult thrips have thin, elongated bodies, feather-like wings and small, dark eyes (Figure 1). Thrips range in color from brown to yellow to cream, depending on the species, sex and life stage. Immature thrips (larvae) are also elongated, and mostly resemble adults though smaller and often more translucent (Figure 2).
They often fly (albeit terribly) under the radar, almost invisible to the naked eye– here's how to spot signs of thrips, treat them, and beat them! Thrips are tiny, elongated, winged insects that are usually pale, brown or black in color and move quickly.
Thrips usually feed on the juices of vegetables but if they reach human skin they can suck the epidermal lymph after biting. The cutaneous lesions formed are small pink and itchy papules localized mainly on the trunk and the arms.
Observing the flight of thrips can also help identify an infestation. Thrips have a distinctive, erratic flight pattern due to their small size and fringed wings. They are usually more active in warm and sunny conditions, which can lead to increased visibility and detection.
These pests sometimes bite humans in search of moisture on the skin and will also cause slight irritation to the toes and feet should one walk through grass barefoot. Thrip bites only cause minor irritation and do not usually have long-term effects.
Spider mites, the tiny (1/32-inch long) eight-legged relatives of insects, produce damage similar to that of thrips. However, they use their mouthparts to first pierce plant cells and then to suck out the contents.
Most adult thrips are elongate, slender, minute (less than 1/20 inch long), and have long fringes on the margins of both pairs of their long, narrow wings. Immatures (called larvae or nymphs) are oblong or slender and elongate and lack wings.
Thrips feed on plant sap and on hot and humid days they congregate on window sills in large numbers. With climatic changes, these insects become more of a problem and can get into clothing and hair.
Spread of tospoviruses
All tospoviruses are transmitted by thrips and cannot be spread by other sap-sucking insects (e.g. aphids, leafhoppers) or chewing insects (e.g. beetles). The transmission process is a complex biological system.
They occasionally or seasonally invade homes and can enter via the gaps in the flywire screens. They are attracted to white objects. Cloth nappies (the old days!) on the clothes line or white sheets, jumpers or shirts get covered with thrips.
Thrips are small, winged insects with rasping-sucking mouthparts. They are generally less than 1/8th of an inch long. Their bodies are elongated, more like a grain of rice than the rounded shape of aphids and mites.
Chiggers are tiny orange, yellow or red parasitic larvae of certain types of mites. They can attach to people and cause intense itching and small, reddish welts on the skin. Chiggers are attracted to areas of the body where clothing fits tightly over the skin or where the skin is delicate.
Diurnal flight activity patterns of the adult thrips peak between 8:00 a.m. to 10:00 a.m. and again between 2:00 p.m. to 4:00 p.m. in greenhouses, so avoid spraying during these periods when the thrips adults can easily fly away.
Thrips won't disappear quickly, but they will eventually. As a preventative, keep your plants clean and observe them closely for signs of damage or jumping dust flecks. If you do encounter thrips, don't be too discouraged. You are not alone.
Thrips have six life stages: egg, first instar and second instar (called nymphs or larvae), third instar (prepupa, or propupa), fourth instar (pupa), and adult. They have multiple generations per year.
This is a tactile hallucination known as formication. People with this condition are convinced the bugs are real, even with reassurance from others they are a hallucination. This makes formication difficult to treat for the person and their medical provider.
Snow fleas just another name for springtails, which are not fleas at all. One of the ways that you can occasionally see springtails is while you're shoveling snow. They live in leaf litter and soil underneath the snow and look like dirt of black flecks against the white snow when they're uncovered.
Signs or Damage of Thrips
Plants become stunted. Leaves crinkle and drop. Fruit becomes deformed, scarred or scabby.
Use a pyrethrin spray or another type of oil-based spray for the best results. This spray combines insecticide with fatty oils to smother and poison thrips. Introduce predators: Insects like minute pirate bugs, ladybugs, Trichogramma wasps and lacewings love to munch on thrips.
Thrips are attracted to the colors yellow and blue, so yellow and blue sticky cards are an effective way to monitor populations (Figure 11). The cards should be placed among plants just above the canopy level so that the insects are caught during flight. Blue or white water pan traps can also be used for monitoring.
Thrips develop through two quiescent, non-feeding pupal stages in the soil, plant litter or in a protected area on the plant. Adults emerge and resume feeding on flowers, buds, and terminal foliage. The entire life cycle from oviposition to adult emergence can take 12 days in hot weather to 44 days in cool weather.
Thrips eat away at the leaf surface, leaving silvery scratch marks – if you see this kind of leaf damage, check both sides of the leaf – look for the light yellow larvae and/or the thin black adult thrips.
The wings are usually fairly simple and straplike. At rest they are laid over the abdomen but never folded. Typically the wings have long posterior hairlike fringes with shorter fringes occurring on the leading edge. The abdomen is elongated and generally flattened dorso-ventrally, especially in the Tubulifera.
Often, damage first appears as a stippling of light dots on the leaves; sometimes leaves turn a bronze color. Heavily infested leaves can turn yellow and drop off. Damage is usually most severe in hot, dusty conditions and on water-stressed plants.