Oriental Cockroach Nymphs
Oriental cockroach egg cases, or oothecae, are dark and reddish-brown in color. Measuring approximately 8 to 10 mm in length, they appear to be slightly inflated. Each female is capable of producing between one and 15 oothecae, which contain approximately 16 eggs each. Females deposit the oothecae in sheltered, protected locations near food and water supplies. Oriental cockroach nymphs appear extremely similar to adults of their species. Female nymphs are broader and heavier than male nymphs. The nymphal stage spans approximately one year, during which time Oriental cockroaches molt several times.
Nymphs also exhibit habits similar to those of adults. Whether inside or outside, they are found near decaying organic matter. In yards, they hide well beneath leaves and the mulch of flowerbeds. They can also thrive in high-moisture areas such as sewers, drains and basements. Both nymphs and adults of this species are sluggish and tend to prefer below-ground-level indoors.
Oriental cockroaches observe a seasonal developmental cycle. They seem to develop more quickly during the rainy part of the year. The peak of adult population is in late spring or early summer and slows considerably by late summer and into early fall. If nymphs have not yet reached maturity by the fall, they will usually not become adults until spring.