06/11/2026
New World Screw Worm Fly update.
As producers, pet owners, wildlife managers and enthusiasts face this situation, its necessary to recognize how these insects "work".
A female fly (understand it will seldom be just one) finds an animal with some type of scratch or wound. It may also be the naval area/umbilucus of a new born.
They land at the wound and begin laying eggs at the edge. The female fly can lay 100 to 400 eggs at a time.
In 12-24 hours, the larvae hatch and begin feeding on the flesh.
They will feed on the animal for ~5-7 days. After this period, if they haven't killed the animal already, they will fall off to the ground where they will pupate and develop into flies which will start the process all over again.
As noted, a heavy infestation and kill the animal. In a young calf this process van take only a few days.
So the entire process may only take 8-10 days.
So given how this work it is important:
1) to be vigilant and check animals regularly.
2) put an aggressive fly control/deterence program into place.
3) potentially use approved products that can prevent an infestation.
This is in addition to alerting your vet and collecting samples.
Please reach out if you have any questions or if there is anything we can help with.
