Can samurai wasps control stink bugs?

Stink bugs have become one of the most prolific and fast-breeding pests in North America. They are an invasive species and were likely brought to America via shipping containers. Since stink bugs are a hardy species, very capable flyers, and adaptable to a wide variety of environments, they have thrived here. Since there have been no natural predators for the brown marmorated stink bug in the U.S., the pests have continued to multiply and become a bigger and bigger threat to agriculture.

However, scientists believe a solution may have presented itself with the arrival of a known predator of stink bugs: the samurai wasp.

If you think you have an infestation of stink bugs around your home or property, contact your local Western Exterminator office today and discuss how we can help.

What are stink bugs?

The brown marmorated stink bug is an insect in the Pentatomidae family. These insects are native to Asia and specific countries like China, Korea, and Japan. They were accidentally introduced to the United States, it is believed, sometime around 1998. The first specimen was found in Pennsylvania in that year, and since then, they have adapted and reproduced to become pests in nearly all states.

The stink bug is a small insect that is shield-shaped and the brown marmorated stink bug has a brownish color with white markings along the edge of their backs. They have two long antennae on their heads. These insects are usually, just over half an inch in length, and are almost as wide as they are long.

Brown marmorated stink bugs feed on fruits and vegetables. These insects have mouthparts which pierce the skin, and they suck out the juices. When they leave, the area they feed upon develops a brown, puckered area, which makes the vegetable or fruit unsalable.

Why are stink bugs considered pests?

Brown marmorated stink bugs are considered pests due to the significant damage they can cause to crops and vegetation. Few natural predators exist in North America, allowing stink bug populations to grow unchecked. They feed on fruits and vegetables, rendering the produce unsellable. Their presence in homes is also a nuisance, as they emit a foul odor when disturbed.

Sealing entry points, vacuuming indoor populations, and using insecticides can help control populations. However, this can only offer some temporary relief. Now, scientists are exploring biological control options. But what eats stink bugs? Research has led to the discovery of the natural enemy of stink bugs: samurai wasps.

What are samurai wasps?

The samurai wasp is a small parasitoid wasp of the family Scelionidae, which is known to be a predator of the brown marmorated stink bug. In fact, it is a very specific flying insect that targets the stink bug for a very specific reason.

Samurai wasps prefer to use the brown marmorated stink bug in order to lay their eggs. These wasps do this in a very sneaky way. They are so tiny that they can lay their eggs inside the stink bug eggs. When the wasp larvae hatch, they destroy the stink bug egg and feed off the larva inside. An adult wasp will emerge from each affected stink bug egg.

The wasps are very small and pose no stinging risk to humans since they do not have stingers. Their bodies are black in color with small white bristles on their back, and they have brown or orange-colored legs. Samurai wasps also have bent antennae sticking out of their forehead and large segmented eyes.

Samurai wasps vs stink bugs

Scientists have been searching for a way to control stink bug populations since they first appeared in Pennsylvania in 1998. In an effort to find a natural solution, researchers traveled back to their place of origin in Asia. There, they discovered the samurai wasps, a parasitoid species of wasp known for attacking brown marmorated stink bug eggs. Recognizing their potential, scientists imported the wasps to the U.S. for further study.

Interestingly, before any official releases, the samurai wasps were detected in Maryland. They had likely arrived through the same means as stink bugs—via shipping containers. Scientists quickly captured and studied them, eventually organizing controlled releases.

Research shows that in their native habitat, samurai wasps can parasitize 80% to 100% of brown marmorated stink bug eggs. This makes them a promising biocontrol agent. By increasing the population of samurai wasps through monitored releases, scientists hope to establish a long-term, sustainable solution for managing brown marmorated stink bugs.

Why are samurai wasps considered the natural enemy of stink bugs?

Samurai wasps have evolved to specifically target brown marmorated stink bugs, making them an effective biocontrol agent. Unlike other parasitoid wasps, they exhibit a strong preference for stink bug eggs due to the chemical cues these pests emit. These cues, along with the plants that stink bugs feed on, guide the wasps directly to their host.

Laboratory studies have shown that samurai wasps can parasitize native stink bug species when no other options are available. However, field studies indicate they overwhelmingly choose brown marmorated stink bug eggs. This suggests that in natural conditions, they should target this invasive pest rather than native species.

Call Western Exterminator for stink bugs

Although the use of samurai wasps has moved across the country and is now being considered in the Western U.S., the most effective way to get rid of stink bugs is to contact professionals like Western Exterminator. Stink bugs can get between the walls of a house and then reproduce quickly, infesting a home and coming out into interior spaces throughout the year. If you think your home has a problem with brown marmorated stink bugs, contact your local Western Exterminator office today.

Check out our guide to find out more about wasps and what different species are capable of.

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