With a name like insidious flower bugs, I had to write about them.
These predatory insects are a type of minute pirate bug. They eat many small garden pests and their eggs. And they bite.
Insidious flower bug bites
Yes, insidious flower bugs (Orius insidiosus) bite. We don’t know why. And it hurts. A lot. Some people react to these bites with welts, swelling, or redness, while others have no reaction [other than the pain]. Since these insects are not quick to fly away after biting, you may get some satisfaction out of ending them, but that wouldn’t be in your garden’s best interest. And insidious flower bug bites cannot actually harm you. In fact, they are so tiny that robber flies eat them. [Thanks to Jim Elve for permission to use this amazing photograph!]
Despite their bite, insidious flower bugs really are beneficial. They feed heavily on thrips [their favorite food], corn earworm eggs, mites, spider mites, small caterpillars, bollworms, whiteflies, scale insects, European corn borers, armyworms, potato leafhoppers, and a slew of aphid varieties, including spotted tobacco aphids, corn leaf aphids, and potato aphids. Insidious flower bugs are so beneficial, that they are raised commercially as a biological control against thrips, European red mites, twospotted spider mites, and most aphid varieties in eggplant, strawberry, cucumber, and sweet peppers crops. Research conducted in Florida found that insidious flower bugs were more effective at controlling thrips on sweet peppers than insecticides. Other research has demonstrated similar results with twospotted spider mites on bean plants, and soybean aphids on soybeans.
Insidious flower bug description
These mixed blessings are small, only 1/5 of an inch long. They tend to be flattened, with an oval to triangular shape. They are black with white markings. Nymphs are yellowish-orange to brown, wingless, and teardrop shaped. If you look at an insidious flower bug under a microscope, you can see that they have piercing mouthparts, called beaks, which they use to repeatedly stab and suck the juices from their prey.
Orius insidiosus lifecycle
Insidious flower bugs seem to come out of the woodwork in late summer, though they have been around since they hatched, starting in spring. Eggs are laid in plant tissue, then hatch into nymphs, going through five instars before reaching adulthood. This takes approximately 20 days, and there can be several generations a year. Most of their diet consists of insects and insects eggs, but they occasionally eat plants and pollen when prey is scarce.
Attracting insidious flower bugs
Despite the bite potential, these predators are good to have around. You can attract them to your garden by growing alfalfa, buckwheat, soybeans, cotton, grapes, and most deciduous fruits.
You can reduce the chances of getting bit by wearing dark clothing on hot days in late summer. For the most part, insect repellants do not work against these garden visitors.
You can grow a surprising amount of food in your own yard. Ask me how!