Grade 8 Science : Life Cycles of Living Organisms - Part 5

The life cycle of a cockroach consists of three major stages namely, the egg, nymph and adult stage. The eggs are typically found in a sac that is attached to the adult female cockroach from the outside and it is said that there are approximately five to fifty eggs in a sack. However, in the case of some cockroaches, eggs could be found in a sac that is located inside the adult’s body. These eggs are usually laid in warm, safe places and they look similar to tiny capsules. These eggs take around two months to hatch and it should also be noted that high temperature is a driving force for their development.

 

The nymphs come out from the cage once the eggs are hatched and they are initially white in color. When they grow, the body color will gradually take a brown or a grey hue. The nymphal stage is a period in which they undergo a series of molts and as they shed their skin, their growth takes place. The molts, which are also known as instars, take place when the nymphs grow bigger while they shed their exoskeletons/skin.  The softness inculcated in their bodies gradually reduces with time at this stage. Their size and color changes drastically as they undergo and finish the last molt. Upon the completion of the last molt they become adults and it will take around a year for them to enter this stage.

 

 

The life span of adult cockroaches is roughly two years. However, it should be noted that their life span heavily depends on the temperature, species and moisture. Eventually, the life cycle continues as they begin to reproduce as they are sexually active at the adult stage. The life cycle of cockroaches reflects incomplete metamorphosis as the nymphs showcase a majority of morphological features that appear similar to those of the adult cockroaches. 

 

 

 

 

 

 

 

 

By Mekhala Egodawele

Photo source : Internet