What does capturing adult cockroaches and various sized nymphs in a sticky trap usually indicate?

Capturing adult cockroaches and various sized nymphs in a sticky trap typically indicates a large, longstanding population. This is because finding a mix of life stages—both adults and nymphs—suggests that there is an established breeding population thriving in the area. The presence of nymphs indicates that successful reproduction is taking place, which is characteristic of an ongoing and significant infestation rather than a new or solitary one.

In contrast, a new invasion from outside would likely show primarily adults or only a few nymphs at first, since immature stages tend to take time to develop from eggs. A single recent infestation might not reveal both adults and nymphs in significant numbers within traps. Lastly, capturing these stages does not typically suggest the end of an infestation cycle, as the continuous presence of both life stages points towards a robust population still actively thriving in that environment. Thus, the ongoing capture of multiple life stages confirms the existence of a large, longstanding population of cockroaches.