Adult flies emerge, mate, and oviposit when blueberry plants are producing fruit.
After about two weeks, an adult fly emerges from the pupa.
This stage lasts for about 9 days before the fly finally emerges as an adult.
When spring begins and the flies emerge, they appear shrunken because their fat was used up during the winter.
It spends its larval stage in the weedbeds of slow flowing rivers and when the fly emerges, the female seeks a blood meal before mating.
Pupation lasts six weeks, after which the adult fly emerges.
The adult flies emerge during the morning low tide.
Black flies invariably attack in swarms as the larvae emerge from the same cold mountain streams where the trout dwell.
When new adult flies emerge they instinctively fly towards light.
The adult fly emerges in two to four weeks and repeats the cycle, creating several generations each year.