Western flower thrips

Frankliniella occidentalis

The adult thrips are approximately 1.3-1.4 mm in size, light yellow to dark brown in color with 2 long wings lengthwise over the total body. The species closely resembles Thrips tabaci, but is usually a little lighter. The larvae are slightly more yellow or orange in color than the adults and wingless. Eggs are kidney-shaped, white and 0.2 mm. They are placed in plant tissue and are therefore difficult to see. Occasionally places where eggs are laid can be recognized due to some deformation at those spots on the outside of the leaves.

Damage of western flower thrips:

Adult thrips are found mainly in the upper part of the plant. If there are flower buds present, the thrips are attrackted towards them because of the pollen. They suck from petals and cause irregular spots on the flowers. Most damage is done by the nymphs of the western flower thrips. Nymphs as well as adults suck from leaves, growth buds and young flower buds. On leaves, thrips feeding causes silver-gray spots with dark dots, the excrements of the thrips. In buds puncturing of plant tissue causes damage such as distorted growth of young buds and sometimes even growth stops and buds wither and fall off.

Western flower thrips is known to be a virus transmitting species. esp. tomato spotted wilt virus.

life cylce western flower thrips:

  • highly dependent on temperature
  • female lays 50-100 eggs
  • development time: 7-20 days
  • pupation in the soil
  • adult lifetime one to several weeks

host plants western flower thrips:

  • very polyphagous
  • serious damage in many vegetable and horticultural greenhouse crops

Products against western flower thrips:

Amblyseius swirskii:


Orius laevigatus:


Neoseiulus cucumeris:


Amblydromalus limonicus:


Franklinothrips vespiformis:


Stratiolaelaps scimitus:


Macrocheles robustulus: