Hosts or Prey
Mostly plant-feeding spider mites (family Tetranychidae) and their eggs
Identification
Adults and last instars are about 1/8 inch (3 mm) long and pale yellow to whitish. Adults have long, hairlike fringes on the margins of their wings. At rest three dark spots are apparent on each whitish forewing; these six dark wing spots on a pale yellow to whitish thrips generally distinguishes this species from other thrips common in California.
The sixspotted thrips larva is translucent white to yellowish. In comparison with similar-looking pest thrips, this predator is common only where mites are abundant and can often be seen feeding on the mites.
The prepupa is recognized by the presence of wing buds and antennae that are straight and forward projecting. The pupa also has wing buds, but the antennae are folded back over the head.
Life Cycle
Thrips hatch from an egg and develop through two larval instars, prepupa, pupa, and adult. Eggs are laid in plant tissue and hatch almost immediately.
Egg to adult development time during the growing season is about 10 days. Sixspotted thrips has many generations per year where temperatures are warm and mites are abundant.
Habitat
Sixspotted thrips can be found on most any plant infested with spider mites. It also feeds on exposed species of mites that produce little or no webbing, but webspinning mites are preferred prey.
Sixspotted thrips feeds on all stages of spider mites, but prefers the immatures. It consumes large numbers of prey, has a high searching capacity, requires relatively few prey to survive, and is an effective searcher at low prey densities.
Females produce a relatively high number of eggs for each prey they consume. Sixspotted thrips larvae consume about 10 mite eggs, larvae, or nymphs per day. Adults can consume about 60 mites per day.
Species
At least three Scolothrips species occur in California. These are Scolothrips longicornis, and S. sexmaculatus and S. pallidus, which closely resemble each other and only an expert examination of minute characters can reliably distinguish the species.
More Information
- The Bionomics of Scolothrips sexmaculatus (Pergande) (Thysanoptera: Thripidae), an Insect Predator of Spider Mites, UC Riverside, Hilgardia
- Natural Enemies Handbook, UC Integrated Pest Management Program
- Protecting Natural Enemies and Pollinators, UC Integrated Pest Management Program
- Six-Spotted Thrips: A Gift from Nature that Controls Spider Mites, In Thrips Biology and Management
Scientific classification:
- Phylum: Arthropoda
- Class: Insecta
- Order: Thysanoptera
- Family: Thripidae
