The eggs of the mealworm beetle (Tenebrio monitor) are only visible under the microscope, thus extremely tedious to observe. So are the early stages of the larvae. This may explains the variations in the lengths of each stage of its early life cycle provided by different authors. It is reported that the female lays about 500 eggs. And after four to 19 days the egg hatches LINK. The larva feeds on vegetation and dead insects. In culture oat flakes are commonly used. Slices of potato, carrot or apple are added to provide a source of moisture.

The larva is elongated and segmented with three pairs of legs behind the head and a support leg on the last segment of the body (below).

It passes through nine to 20 instars before turning into a pupa (below).

A newly hatched larva is around 3 mm long LINK. It moults 10 to 20 times before reaching about 30 mm long when it changes into a pupa. A newly moulted larva is soft and white, hardening and turning brown with time.
The video below shows the young larvae recorded on 6th September 2016.
…below shows larvae on 13th September 2016.
…and below on 11th October 2016…
Mealworms are cultured mainly for pet food – for fish, reptiles and birds.

They are edible, available as a healthy snack after frying or baking (above) and as a garnish for fried vegetables (below).

Mealworms have the potential of degrading plastics, as reported HERE.
YC Wee
Singapore
15th December 2016