Integrated Pest Management
Thrip
Culinary Camp Week 8
Nicole Schmittou, Cynthia Murphy, Kathryn Furlow, Mary Mcbrearty, and Kirsten Thomas
Introduction
A thrip is defined as a minute black winged insect that sucks plant sap and can be a
serious pest of ornamental and food plants when present in large numbers. There
are many type of thrips, all given a common name based on their host plant. Each
type has a slightly different shape and color and will inflict different types of damage
to their host.
Common pest thrips include:
Common Name
Scientific Name
Host Plants
Damage to Host Plant
Bean Thrips
Caliothrips
Fasciatus
Beans and other
legumes
Brown, distorted leaves
Citrus Thrips
Scirtothrips citri
Citrus and
blueberries
Silvery scars on citrus
fruit; distorted leaves on
blueberries
Greenhouse Thrips
Heliothrips
haemorrhoidalis
Perennials with
thick, broad leaves
like azaleas, laurels,
and rhododendron
Bleached leaves with
black excrement on
underside
Onion Thrips
Thrips tabaci
Onions and garlic
Stippled and scared plant
parts
Western Flower
Thrips
Frankilniella
occidentalis
Peppers, grapes,
strawberries, and
some stone fruits
Stippled and scared petals,
distorted terminals
Thrips can damage their host plant through feeding and/or transmitting vector
viruses. This damage will impact the fruit, flower, leaves, and shoots of the host
plant, and is most detrimental to herbaceous ornamentals and vegetable crops.
Thrips can also injure humans, as they are known to bite and have potential for
causing respiratory and skin irritation.
Management Strategies
There are many predators of thrips that can be utilized to manage their population
and decrease their damage. Green lacewings, minute pirate bugs, mite, and parasitic
wasps are all natural predators. Releasing specific predators based on the specific
threatening species of thrip will be the most effective.
 Minute pirate bugs and green lacewing larvae are predators of citrus trhips
 Parasitic magaphragma mymaripenne wasps are predators of greenhouse
thrips
Some physical management techniques include:
 Use water to knock thrips off from underside of leaves
 Prune injured/infested plants
 Use of aluminum foil or reflective mulch as ground cover
 Remove weeds and grass from host plants to prevent alternate hosts
 Keep plants well irrigated
Organic topical products:
 Insecticidal soaps made from plant oils and animal plants (best used for
small infestations)
o Ex. Safer Soap. A quart of ready to use spray
treats 1,000 sq. ft. If using concentrate, mix
a pint with 6 gallon of water. Apply every 710 days, ideally in the morning and when
outside temperature is less than 90°F to
prevent wilting.

Spinosad, an organic compound occurring in
fermented soil that can be used as an insecticide.
o Ex. Monterey Garden Insect Spray. Combine 4
Tbsp. concentrate per gallon of water and
apply to upper and lower surfaces of foliage.
Sources:
http://www.oxforddictionaries.com/us/definition/american_english/thrips
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7429.html
http://www.planetnatural.com/pest-problem-solver/houseplant-pests/thripscontrol/
http://www.omri.org/home
http://www.biokids.umich.edu/critters/Thysanoptera/