The cockroach that requires the most effort to control is the:

The German cockroach is widely recognized as the species that poses the greatest challenge for pest control. This is largely due to its biology and behavior. German cockroaches reproduce quickly and can produce multiple generations in a short time frame. A single female can produce up to 400 offspring in her lifetime, which means that an infestation can escalate rapidly if not addressed promptly.

Moreover, German cockroaches tend to prefer living indoors, often in close proximity to human food and shelter. They are adept at hiding in small cracks and crevices, making them difficult to locate and exterminate. Their resilience to many common pesticides can further complicate control efforts, often requiring a combination of strategies like sanitation, exclusion, and targeted treatments.

In contrast, the other cockroach species listed may not reach the same population size in a household or are typically found in less invasive environments. Addressing a German cockroach infestation often requires thorough monitoring, education on hygiene, and sometimes the intervention of pest management professionals to effectively eradicate the problem.