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 in North America, 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.

Scientists have been working on ways to control the stink bug populations for years. However, a recent article indicates a solution could be the recent 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 of insects. 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 a pest 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 1.7 centimeters in length and 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 fed upon develops a brown, puckered area which makes the vegetable or fruit unsalable.

What are samurai wasps?

One of the brown marmorated stink bug’s natural enemies is the samurai wasp. What is the samurai wasp? The samurai wasp is a small parasitoid wasp of the family Platygastridae which is known to be a predator of the brown marmorated stink bug. In fact, they are a very specific flying insect which targets the stink bug for a very specific reason.

Samurai wasps may be small, but they prefer to use the BMS in order to lay their eggs. These wasps do this in a very sneaky way. They are so tiny they can lay their eggs inside the stink bug eggs. When the wasp larva hatch, they destroy the stink bug egg and feed off the larva inside. An adult wasp will emerge from each infected 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 antenna sticking out of their forehead and large segmented eyes.

Samurai wasps vs stink bugs

Scientists have been looking for a way to control the population of stink bugs since they first showed up in Pennsylvania in 1998. In fact, scientists looking for a natural solution to getting rid of stink bugs traveled back to their origin: Asia. Scientists looked for the barrel-shaped eggs which are the signature of the stink bug. Before long, they found the samurai wasp and imported this species of wasp to the U.S. for further study.

To the surprise of these scientists, as they were studying the samurai wasp, they got a call from fellow scientists in Maryland. It turned out, the samurai wasps had been transferred to the U.S. all on their own. These same scientists set about capturing these wasps and then corralling them to do controlled releases in areas where stink bugs were causing damage.

Although no one knows for sure if the samurai wasps will have the same result as they did in Asia where they parasitized up to 90% of the eggs of the brown marmorated stink bug, scientists are eager to find out. What the result of having samurai wasps in the environment is also a concern as no one knows what they might do in their different climate.

The cost of stink bugs

Although scientists are a bit worried about what another invasive species might do to the environment, they are certain that the brown marmorated stink bug is causing thousands and thousands of dollars worth of damage to crops and vegetation across the country. The cost of letting stink bugs continue unabated might be devastating to crops and agricultural businesses of all kinds.

So far, studies indicate that the samurai wasps may be an effective biocontrol agent. There is some indication samurai wasps have also laid eggs in native U.S. species, they seem to definitely prefer the brown marmorated stink bug eggs. It will take further study and serious monitoring to see if these wasps will get rid of the stink bug invasion, but also not cause any further problems all on their own.

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 a pest control professional. 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.

For further reading and resources

https://www.pestworld.org/pest-guide/occasional-invaders/stink-bugs/

https://www.sciencemag.org/news/2018/08/scientists-spent-years-plan-import-wasp-kill-stinkbugs-then-it-showed-its-own

https://entnemdept.ufl.edu/creatures/beneficial/wasps/Trissolcus_japonicus.htm