Orius insidiosus, also called the minute pirate bug, is an aggressive thrips predator – possibly the most effective. It attacks and kills all mobile stages of thrips, including adult thrips.
Orius is a true bug, which means it has a long rostrum (feeding tube). It uses its rostrum to pierce its prey, and drain the contents, killing the pest.
A ‘generalist’ predator, Orius feeds on many pest species, such as mites, aphids and moth eggs for food. It will control thrips, and helps in the control of the other pest species.
The adult female is 3mm long and lays (oviposits) two to three eggs per day in plant tissue. Eggs are tiny (0.4mm), and difficult to see. One nymph hatches per egg. Nymphs pass through five stages before maturing. Total development time (egg to adult) is about three weeks. Adults live approximately three to four weeks.
The first nymphs are colourless, and darken as they mature; going from yellow to brown. Fifth-stage nymphs have wing pads. All nymph stages have red eyes. Adults are black and have a characteristic white patch on its back.
Orius females may enter diapause when daylength is less than 12 hours. Releases of Orius are possible during this time, but one should not expect establishment.
Orius is aggressive – it consumes 12 thrips per day but kills many more (45) than it eats.
In addition to its predatory nature, Orius can feed on pollen if prey is scarce. Preventive applications are possible in pollen bearing crops (eg pepper).
Supplemental feeding of Ephestia eggs has been shown to enhance the ability of Orius to control thrips. Ephestia eggs are more nutritious for Orius than thrips. It aids Orius population growth because adult females fed Ephestia lay more eggs per day and live longer. The Orius population increases more and faster than if fed only thrips.