Minute Pirate Bug and Insidious Flower Bug

How to Use Minute Pirate Bug and Insidious Flower Bug for Biocontrol

Biocontrol category:

• Augmentative—must be released/applied repeatedly

• Conservation—attract and protect from the surrounding environment

When to use: When O. insidiosus is shipped in the adult stage, timing of applications should synchronize with peak pest emergence.

Inside or outside

Orius is commonly found searching for prey on many agricultural crops including cotton, peanuts, alfalfa, corn, pea, other vegetables, and strawberry, on pasture land, and in orchards. Adults are often found in corn silks and are most common near spring and summer flowering shrubs and weeds since they feed on pollen and plant juices when prey is not available. Oruis is also successfully released as a generalist predator for pests in greenhouses, especially on cucumber, eggplant, strawberries and bell pepper crops.

Rate: Release rates typically vary by commodity, level of infestation, and location. However, in horticultural crops a release rate of two predators per square meter is typically advised. Specifically in thrips, Funderburk et al. (2009) reported that thrips populations were controlled below economic thresholds when ratios of 1 predator to 40 thrips were implemented.

Pest stage: eggs and immature stages of some insects, as well as the adult stage of other species

Mode of action: Predators in both the larval and adult stages

Conservation: Plantings of spring and summer flowering plants will help Orius survive periods of scarce prey. In addition, because Orius species subsist on a diet of nectar and pollen when prey is scarce, maintaining floral resources may help support local Orius populations. 

Compatibility: Diversified cropping systems, use of microbial insecticides, e.g., products containing Bacillus thuringiensis, and use of economic thresholds to minimize conventional chemical insecticide applications, are all practical recommendations to maximize the natural biological control from Orius. Applications of neonicotinoid, organophosphate, and pyrethroid insecticides can greatly reduce Orius populations. Even soil-applied systemic insecticides may reduce their numbers because they feed on plant juices.

Any time you use a pesticide, you must read and follow the label directions and comply with all applicable laws and regulations related to pesticide use. Also be sure that any pesticide used is approved for use in your country and state/province.

Risk: Orius spp. are capable of biting humans, however it is a rare occurrence and the bite is only mildly and temporarily irritating.

Commercially available: Yes

Learn more about Orius spp.

Orius spp.
(Hemiptera: Anthocoridae)

The minute pirate bug, Orius tristicolor, and the insidious flower bug, Orius insidiosus, are true bugs in the family Anthocoridae. Both species are common predators of a wide variety of small, economically important, soft-bodied arthropods (Funderburk et al. 2000). Both species are commonly found in the United States with O. insidiosus being most common in the Midwest and east, and O. tristicolor more common in the western United States (Herring 1966). There are over eight species found in the United States. 

Oruis adults are very small, ~3 mm in length, oval-shaped, and black with white wing patches and wings that extend beyond the tip of their body. Nymphs are small, wingless and yellowish-orange to brown in color, teardrop-shaped and fast moving. Unlike adults, nymphs are less than 3 mm in length, and wingless, however they share the characteristic teardrop shape with adults. Nymphal instars often range in color from yellow to brown. Both adults and nymphs are highly mobile and feed by sucking juices from their prey through a sharp, needle-like beak (the rostrum) used to consume the insides of prey. 

2-3 days after mating, female Orius lay cream colored eggs ~0.4mm in length discretely within plant tissues where they can develop without interference from other predators. Once hatched into nymphs, Orius offspring develop through five nymphal stages. The development from egg to adult takes a minimum of 20 days under optimal conditions and females can lay an average of 129 eggs during their lifespan. Because adults live about 35 days, several Orius generations may occur during the growing season, however when day length is less than 14 hours, adults will enter a quiescent resting state (Ruberson et al. 2000). 

Orius species in Agriculture

Orius species can be found on many agricultural crops including cotton, peanuts, alfalfa, corn, pea, and strawberry, on pasture land, in orchards, and is successfully used as a biological control agent for thrips and mite infestations especially on cucumber, eggplant, strawberries and bell pepper in greenhouses with both nymphs and adults consuming more than 30 spider mites per day (Frescata and Mexia 1996, Funderburk 2009). Both nymphs and adults feed on a variety of small prey including thrips, spider mites, insect eggs, aphids, and small caterpillars. Orius hold their prey with their front legs and insert their beak into the host’s body, generally several times, until the soft body is empty and only the exoskeleton remains. It has been reported to be an important predator of the eggs and new larvae of the bollworm and of spotted tobacco aphid, but it is believed that thrips and mites are the more basic part of the Orius diet (Baez et al. 2004). Other reported prey include eggs and small European corn borers, corn leaf aphids, potato aphids, and potato leafhopper nymphs. Orius species can also be found in corn silks in the spring and summer, as well as flowering shrubs and weeds since they feed on pollen and nectar when prey populations are low. 

Plantings of spring and summer flowering plants will help Orius species survive periods of scarce prey. In addition, because Orius species subsist on a diet of nectar and pollen when prey is scarce, maintaining floral resources may help support local populations. 

Diversified cropping systems, the use of microbial insecticides, and the use of economic thresholds to minimize conventional insecticide applications are all practical recommendations to maximize the natural biological control of Orius species, because applications of neonicotinoid, organophosphate, and pyrethroid insecticides can greatly reduce Orius populations (Funderburk et al. 2000). Even soil-applied systemic insecticides may reduce their numbers because they feed on plant juices. 

Commercial Availablity of Orius insidiosus

Orius insidiosus is currently commercially available for mass release through multiple US and European vendors. Augmentative biocontrol release rates typically vary by commodity, level of infestation, and location. However, in horticultural crops a release rate of two predators per square meter is typically advised. Specifically in thrips, Funderburk et al. (2009) reported that thrips populations were controlled below economic thresholds when ratios of 1 predator to 40 thrips were implemented. Orius insidiosus is shipped in the adult stage. Commercial producers of Orius insidiosus recommend its use in greenhouses, fields, interiorscapes, orchards and gardens.