Describe the stages of development in cockroach.

1. The development in cockroach (Periplaneta americana) is paurametabolous as the development occurs through nymphal stage. Fertilized egg → Nymph → Adult 

2. The nymph looks like adult but it is smaller and sexually immature. 

3. After sufficient growth, nymph undergoes moulting and enters into a stage between two successive moults known as instar. 

4. Cockroaches may undergo moulting for around 13 times before reaching the adult stage.

5. The nymphal stages have wing pads but only adult cockroaches have wings. 

6. The embryonic period in cockroach varies as per temperature and humidity. At 24°C, the duration is about 58 days and at 30° C, the duration is about 32 days.