Some call them ladybirds, lady beetles or ladybird beetles. We’ll stick with ladybugs, although the ladybug is not really a bug, but a beetle .
Most species of ladybugs are considered useful insects since they eat aphids and scale insects. In other words, they provide organic pest control. ‘A single lady beetle may eat as many as 5,000 aphids in its lifetime.’ .
There are four phases to the ladybug’s life cycle: eggs, larvae, pupa and adult. It will take several weeks to go through the entire cycle. Some species will have several generations each year while others have only one.
One ladybug can lay anywhere from 2 to 350 eggs . This clutch has 28 eggs.
In the larval stage they look like little alligators and are voracious aphid eaters. Once hatched, the larvae eat about 350 to 400 aphids in the 2 weeks it takes them to become fully grown  . They go through 3 or 4 cycles of shedding their skin before entering the pupa stage. Each iteration is called an instar .
The larva will attach itself to a leaf or twig and transition to the pupa stage. It will remain in pupa form for 2 to 3 days before emerging as fully formed ladybug.
The newly hatched ladybug will have no spots for the first few hours and will will open and close their wings to dry them. Slowly the spots will appear.
The short movie below shows the full cycle.