Twospotted spidermite

Tetranychus urticae
Appearance:

the color of the mite depends on the host plant, ranging from orange, light yellow, or light green to red, brown or nearly black. When many spider mites are present, there is often quite some webbing on leaves but mainly around plant tips. Female dpider mites lay their eggs in this webbing to protect them for drying out and for being eaten by predators. Adult mites have two dark spots on their flanks. Females enter diapause in adverse conditions (short day, low temperatures and less food). Spider mites that are in diapause, are red in color.

Distribution within the crop::

usually on the underside of the leaves and in the growing tips of the plant.

Damage:

Twospotted spider mites suck from the plantleaves. They puncture individual plant cells that will dry out and shrink because of this feeding by the spider mites. This suction damage inhibits the plant growth and cuases a reduced yield. At a large infestation plants will die completely. Feeding damage as well as the presence of webbing worries ornamental growers also because of the cosmetic damage.

lifecycle twospotted spidermite:

  • female lays about 80 eggs
  • 6 to 8 generations per season
  • development time at 20 °C about 17 days
  • development time at 30 °C about 7 days
  • minimum temperature around 10 °C

host plants two spotted spidermites:

  • very polyphagous
  • bean plants
  • potted plants
  • roses
  • tomatoes
  • egg plant
  • sweet pepper

Products against two spotted spider mite:

Phytoseiulus persimilis:

SPIDEX

Phytoseiulus persimilis low RH:

Phytoseiulus low RH

Neoseiulus californicus:

SPICAL