These bugs are native to China, Japan, Korea, and Taiwan. They were accidentally introduced into the United States — probably as stowaways in packing crates — sometime in the mid- to late-1990s. Today, stink bugs are considered to be agricultural pests.
So what's so stinky about stink bugs? As it turns out, they have stink glands on the underside of their bodies, between their first and second pair of legs. These glands will release an odor as a defense mechanism when the stink bug feels threatened, is injured, or is handled or moved – similar to how the skunk defends itself.
The odor comes from a chemical released by the stink glands. Scientists have identified the odor as coming from trans-2-decenal and trans-2-Octenal. Many people believe the smell is like a very strong version of cilantro, which is a plant often used in Italian cuisine.
Besides stinking, stink bugs also pose big problems for farmers. While some insects – such as bees and the praying mantis – are helpful to farmers, stink bugs regularly cause great damage to fruit and vegetable crops. For example, brown marmorated stink bugs feed on a wide variety of fruits and vegetable crops, including apples, cherries, peaches, raspberries, pears, green beans, and soybeans.
When growing season is over, stink bugs often invade nearby homes. As the fall nights turn cool, stink bugs look for shelter in warm areas. When they get inside a house, they will usually hibernate to survive the winter.