Life cycle: http://www.vtaide.com/png/cockroach.htm PS It depends on roach species, environmen and temperature how long it takes to maturity.The nymph stage of the cockroach lifecycle can take anywhere from a month and a half (German cockroach) to several years (giant roaches).http://www.planetcockroach.com/cockroach... The site above shows average values and in these values normally lowest and highest are not be taken into account.ife cycle: http://www.vtaide.com/png/cockroach.htm PS It depends on roach species, environmen and temperature how long it takes to maturity.