Hi friend, I may not be to the point on your question but here are some interesting facts and details about cockroach that may try and answer your questions regarding cockroaches....
males thoraxes are narrower and are longer in length than the females
Yes! but once impregnated the female is fertilized rest of her life. This basically means that cockroaches do not need to keep mating to get pregnant.
Males have narrower thoraxes, and are somewhat longer.
Male cockroaches are smaller in size than female&male cockroaches have anal styles from 9th segment of their body while female don't.