What are thrips?
Thrips are tiny winged insects that feed on plants by puncturing cells and sucking up the contents. There are over 6,000 species of thrips worldwide, with around 100 considered significant plant pests. Thrips are very small, usually measuring only 1-2 mm long, and are slender insects with fringed wings. They can be various colors like white, yellow, brown or black. Thrips have asymmetrical mouthparts adapted for piercing plant tissue and sucking up fluids. Their lifecycle includes egg, larval, pupal and adult stages. Thrips can reproduce rapidly, with some species producing multiple generations per year.
Do thrips infest houses?
Thrips are not considered household invaders and do not infest homes. However, they may occasionally be carried or fly into houses inadvertently. Thrips primarily live outdoors and infest plants, trees and crops. But if thrips get into your home, they do not pose any structural or health threats to residents.
Thrips found indoors are likely accidental invaders that flew or were carried in from outdoor populations. They cannot reproduce or establish infestations inside homes. Thrips lack nesting behaviors and do not damage household materials, furnishings or foods. Nor do they bite or sting humans or pets. The few thrips found inside are simply lost nuisances.
Common ways thrips enter homes
There are a few common ways thrips may find their way into a home:
- Riding on furniture, clothing, bags, boxes or other items moved from an infested area outside into the home
- Being carried indoors on potted plants, flowers or produce
- Flying through open windows, doors, vents or other access points from outdoor populations
- Hitchhiking indoors on pets’ fur
Thrips are most likely to inadvertently enter homes during times of peak activity outside, often in spring, summer or early fall. A few factors make accidental thrips entry more likely:
- Homes located near agricultural areas with large thrips populations
- Presence of heavily infested gardens, trees or landscaping close to the home
- Front, back or garage doors left open allowing thrips to fly inside
- Windows habitually left open without screens
- Air circulation systems or vents providing access from outdoors
So while thrips do not intentionally infest indoor areas, they can occasionally find their way inside homes through various means. But this does not result in reproducing populations.
Signs of thrips in a home
Thrips are small and cryptic insects, but there are a few signs that may indicate thrips presence in a home:
- Seeing adult thrips flying around or landed on windows, walls, furniture, etc. They appear as tiny slender winged insects.
- Noticing black specks (thrips feces) on windows or other surfaces. This is rare indoors though.
- Finding thrips larvae, pupae or dead adults in window sills, floor cracks, spider webs, light fixtures, etc.
- Indoor plants or produce showing signs of thrips damage like discolored spots, scarring, wilting, etc.
But again, seeing a few thrips inside does not mean there is an infestation or reproducing population in the home. Only 1-2 thrips flying around or spotted on occasion likely represent accidental invaders, not an indoor colony.
Do thrips bite humans?
Thrips do not bite, sting or transmit diseases to humans. They have mouthparts specially adapted for piercing and sucking fluids from plants – they cannot puncture human skin. While thrips can occasionally land on people if extremely abundant outdoors, they have no interest in feeding on humans or ability to bite. Thrips are considered completely harmless to people.
Some people wonder if thrips can bite at night while crawling on skin. However, thrips avoid light and are not attracted to humans. They only feed on plants, not blood. So thrips do not pose any biting risk to people sleeping.
Preventing thrips from entering
Though occasional thrips in a home are harmless, you can take some steps to avoid inadvertent entry:
- Keep doors, windows and vents closed or install tight insect screening
- Caulk, seal and weatherstrip possible entry points like cracks around doors and windows
- Inspect items like plants, flowers, vegetables, luggage and clothing for thrips before bringing indoors
- Remove heavy thrips infestations from trees, garden plants, etc. close to the home
- Use positive ventilation and keep air circulation systems closed during times of high outdoor thrips activity
This helps limit thrips access to the home so only rare stray individuals may enter accidentally. With diligence, indoor appearances can be minimized.
Getting rid of thrips
If a few thrips do end up inside, you can easily remove or kill them as follows:
- Manually swat, crush, trap or vacuum up any thrips you see flying or crawling
- Use a fly swatter or sticky trap to capture thrips on the wing
- Apply insecticide sprays to kill thrips landed on surfaces (use products labeled for flying insect or home invader control)
- Improve sealing and screening to prevent more outdoor thrips from entering
With small indoor populations, these direct control tactics can help eliminate stray thrips. For heavy infestations outdoors, more intensive management in gardens, trees and landscape plants may be needed.
Thrips management in gardens and landscapes
To reduce thrips populations outdoors and limit entry into the home, options include:
- Remove infested plant material and use preventive insecticides on new plants
- Apply insecticidal soaps, horticultural oils or neem oil to control larvae/adults
- Use beneficial predatory insects like minute pirate bugs, predatory mites and nematodes
- Apply appropriate foliar insecticides for thrips control on infested species
- Use reflective mulches to deter thrips from plants
- Remove flowers and buds which attract thrips
- Clean up debris, remove weeds and improve drainage to eliminate thrips habitat
Combining several tactics provides the best management of outdoor thrips populations. Consult your local garden center or extension office for products and strategies best suited to your landscape plants and location.
Professional thrips control
For severe residential thrips infestations outdoors, you may require professional pest control. Companies have access to specialized equipment, insecticides and application techniques for maximum thrips elimination. They can provide services like:
- Power spraying plant foliage with insecticidal soaps or oils
- Treating turf, ground cover, mulch and soil areas to destroy pupae and emerging adults
- Injecting systemic insecticides into trees for residual protection against thrips
- Applying targeted pesticides via airblast sprayers, foggers or soil drenches
- Conducting multiple coordinated applications to disrupt the thrips life cycle
Professionals also know the most vulnerable life stages to target and timing applications for optimal results. For the highest level of thrips control on residential properties severely infested, contacting a pest control company is recommended.
While thrips themselves do not invade or infest homes, they can occasionally gain accidental access from outdoor populations. Preventing entry involves exclusion, sanitation and landscape management techniques. Indoors, manually removing or killing the few thrips present is usually sufficient. Overall, thrips pose little threat to households other than sometimes becoming a nuisance. With proper preventive and direct control measures, indoor appearances can be minimized.