Two Spotted Mite

Tetranychus urticae

Family: Tetranychidae

Order: Acarina

Class: - Arachnida (Spiders)

Description:

Adult

Colour - Variable, Winter - bright orange; Summer - greenish with large dark spot on each side of body.

Size - Adult Female .85 mm long. Female > Male

Legs - 8.

Biology:

Life Cycle:

Winter - Male die and female become bright red and migrate down host to soil or protected location to hibernate until spring.

Spring - Female change red to green, migrate to young leaves, lay eggs (spherical and pale, clear on leaves) hatch in 7 days as 6 legged nymphs. Develop to adult (8 legs) in 5 to 14 days depending on conditions. Under optimal conditions (warm/dry) can be 9 generations/season.

Habitats:

Origin and History:

Distribution:

Significance:

A destructive pest on a wide range of glasshouse garden ornamentals, vegetables, fruit trees, nursery, crop plants and fruit trees during summer. Adult mites are usually found on the underside of leaves. Damage results when the mites insert their fine, needle like mouthparts into the leaf tissue to extract the cell contents which includes chlorophyll. The first signs of damage is a while speckling of leaves. If feeding continues unchecked leaves become mottled and yellow or bronzed with an unhealthy appearance. In severe cases the leaves turn brown and fall off prematurely thus reducing vigour or yield.

Management and Control:

Culturally - They prefer dry, warm conditions, so, in glass house situations overhead watering can keep population low.

Hygiene - keep alternate hosts i.e. grasses out.

Biological - predatory mite - Typhlodromus occidentalis and lady birds.

Chemical - Ekatin and Metasystox.

Related Species:

Similar Species:

References:

WADA Farmnote "Two Spotted Mite".

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.