Which insect buzzes like a bumblebee and can emit a pungent odor when handled?

The Western conifer seed bug is known for its distinctive buzzing sound that resembles that of a bumblebee, which can occur when it is disturbed or threatened. This buzzing is produced by the insect's wings and is often a surprising characteristic of this pest, as it can lead people to mistakenly identify it as a more benign creature.

Additionally, when handled or threatened, the Western conifer seed bug can release a pungent odor as a defense mechanism. This odor is a way for the insect to deter predators, making it an interesting example of chemical defense behavior in insects.

In contrast, the other options do not have these characteristics. Millipedes, while sometimes producing chemical defenses, do not emit a buzzing sound. Centipedes are predatory but are also not known for buzzing. German cockroaches might emit an odor, particularly in large numbers, but they do not buzz and their odor isn't specifically pungent like that of the seed bug. Thus, the Western conifer seed bug is correctly identified for its unique sounds and defensive odor.