Some bugs that are tiny and white include whiteflies, maggots and, if the term "bug" is used loosely, white mites. There are also many species of beetle that are small and white when immature, having larva similar to maggots.
Whiteflies are very small, triangular insects with pure white bodies at maturity. They infest plants and suck sap from them with their specialized mouthparts.
Maggots are young, worm-like flies. They are about the size of a grain of rice and can often be found on garbage, fruit or decaying meat.
White mites are actually not insects. They are more closely related to spiders than to flies and even spin webs. Like whiteflies, they feed on plants.
Many species of insect, especially beetles, have larval forms that are tiny and white. They can be found feeding on root stock in gardens. These small white grubs can be difficult to distinguish from one another until they reach maturity.