But this strategy is so successful that massive human attempts to eradicate these blood-sucking flies have failed. Some females retain their developing eggs inside their body and their young emerge alive to further improve the survival chances for their young. All scorpions do this, and some beetles, cockroaches. Many aphids and the tsetse fly does this. Oviparity is just plain laying eggs like most arthropods do.
Eggs have yolk and they develop outside the parent.
Many arthropods exhibit parental care to ensure their young survives. Parental care is taken to extremes in social insects where the young cannot survive without the care of insects from the previous generation.