Tip Top Bio-Control Technical Bulletin

Orius insidiosus
Minute Predatory Insect

Target Pest:
Frankliniella occidentallis (Western flower thrips), Thrips tabaci (onion thrips). Used to control thrips on greenhouse grown cucumbers, peppers as well as other crops and landscape situations.

Description:
Orius is a predatory bug that feeds on many species of small, soft-bodied insects. Orius pierces its prey with its mouthparts and sucks out the body fluids of its prey. If prey is abundant, Orius kills more thrips than it needs to survive. The presence of pollen favors development of Orius, as it is an alternate food source. Orius can consume 5-20 thrips per day.

Adults are black and white and are about 2-2.5 mm (1/10 inch) long. The nymphs are first colorless, then later become yellow to brown. All stages have red eyes. The eggs are embedded in soft plant tissue and are not very visible. The fresh growing tips and side shoots are choice spots and the release of Orius should be done after side shoot trimming is done if applicable. All stages of Orius move quickly. Adults are great flyers and move efficiently to locate prey. The adults are attracted to flowers. Under ideal conditions each female adult could lay up to 45 eggs over a 2-week period.

Product information:
Orius is a general predator and feeds on thrips, spider mites, moth eggs, whiteflies and aphids. The young nymphs feed mainly on the larval stages of thrips. The older nymphs and adults feed on the 2 larval stages and adult stages of thrips. Orius is delivered in bottles of 500 adults and nymphs usually mixed with buckwheat hulls and or vermiculite. Orius is somewhat cannibalistic and the medium serves as hiding places for the adults.

Release Rates:
Introduce the beneficial as soon as possible after receipt. If storage is necessary, keep them at 10°-15°C (50°-59° F). Preventative introductions are only done in crops that produce pollen. To release, simply sprinkle onto leaves or disperse into Universal release pouch.

General release:
5000-10,000 Orius per hectare (2,000-4,000 per acre).

Specific crop:
Greenhouse cucumbers - .5 Orius per plant or Sq. ft. for 2 weeks
1-4 Orius per plant in hot spots, when thrips populations are established.

Sweet peppers - 2,000-3,000 Orius/1000 sq. yard/ hot spots. Two releases spaced two weeks apart will usually establish Orius.

Lifespan:
A complete life cycle takes approximately 3 weeks. Sex ratio is usually 1:1. Females lay 2 eggs per day, and average about 130 eggs in their lifetime. Egg to adult usually takes 2-3 weeks. Cooler temperatures and lack of prey will slow development. Orius nymphs grow through 5 instars over 2-3 weeks, until they molt to the adult stage. Adults live for 3-4 weeks. Orius will diapause in the fall, when day lengths are less than 12 hours.

Strategic Considerations:
Orius works perfectly together with other thrips predators such as Amblyseius cucumeris and Amblyseius degenerans. Avoid the use of systemic insecticides or pesticides with long residual action.