As the temperatures rise, the brown marmorated stink bugs, which have been sheltered in homes since winter, are beginning to emerge.

The bugs are not native to the U.S. They were accidentally introduced into eastern Pa., according to Steve Jacobs. Jacobs is a Sr. Extension Associate at the Penn State Department of Entomology. The brown marmorated stink bugs are native to China, Japan, Korea and Taiwan.

While initially collected in Allentown, Pa., the stink bugs have been observed in the state of Calif. and many other states in between. Jacobs stated the stink bugs could be traveling on people's cars as they go from state to state.

The stink bug name refers to the odor the bug produce when they are threatened or squashed. The odor comes from scent glands located on the abdomen and thorax of the insect.

The stink bugs are a nuisance to farms as they feed on apples, peaches, blackberries, sweet and field corn, soybeans, tomatoes, lima beans and green peppers. They damaged many Pa. crops last year.

Jacobs said, while it is hard to predict how many stink bugs there will be this summer, "already we have had a spring that is not as warm as last year." A warm spring and summer increases the number of days the insects can reproduce. There were less days this spring that are ideal for the stink bug reproduction.

The stink bugs mate and lay eggs on the underside of leaves from May through August. The bugs will begin looking for shelter from the winter in September and through the first half of October.

Jacobs said, "Each year we see that they have increased their range and the places where they have been seen have had an increase in number."