What is an indication of a newly established cockroach infestation?

The indication of a newly established cockroach infestation can be identified by capturing various sizes of nymphs. When a cockroach population is newly established, it is common to find juvenile (nymph) cockroaches in addition to adults, as this suggests reproduction has already begun. The presence of nymphs indicates that there is an active breeding population, whereas finding only adults may suggest an older infestation that has progressed to the point of visible adults but may not show the early signs of new nymphs hatching.

In a freshly established infestation, you would typically see a mix of both nymphs and adults. The absence of nymphs would imply that the population is not reproducing or has not yet begun the cycle of reproduction, which is essential for establishing a new infestation. Therefore, capturing various sizes of nymphs is a strong indicator of a newly formed infestation, as it shows that the cockroaches are actively breeding and that their population is growing.