How can you identify German cockroaches visually?

German cockroaches are characterized by specific physical features that help in their identification. One of the most distinct features is the presence of two parallel stripes on their thorax, which are typically a lighter color than the rest of their body. These stripes run lengthwise down the back of the insect, making them easily recognizable.

The other characteristics mentioned in the choices do not apply to German cockroaches. They are not large; in fact, they are relatively small compared to other cockroach species. Their coloration is more of a brown to tan rather than bright red, which further distinguishes them from other types of cockroaches. Additionally, some cockroaches may lack stripes entirely, but that would not be true for German cockroaches specifically, as the stripes are a defining feature. Thus, identifying the two stripes on the thorax is key in correctly recognizing German cockroaches.