Horn flies, which infest the backs of cattle, are among the most widespread and expensive external parasites affecting cattle in North America. These pests alone cost cattle producers in the region over $2.3 billion annually, with significant financial losses starting when fly populations surpass the economic threshold of just 200 flies per animal.
To effectively manage horn flies, it's crucial to understand their life cycle. Here's an overview of the horn fly life cycle and how Altosid® IGR plays a key role in disrupting it:
Day Zero: Egg Laying
Female adult horn flies leave the backs of cattle to briefly deposit their eggs in fresh manure. This is where the next generation begins its development. Manure is a vital part of the horn fly life cycle, serving as the breeding ground for larvae.
Day 1-2: Larvae Hatch
The eggs laid by the female flies hatch into horn fly larvae within 1 to 2 days. The larvae thrive in the manure, where they begin to feed and grow.
Day 3-8: Larvae Molt into Pupae
Over the next several days, the larvae undergo molting and transform into pupae.
Day 9-17: Pupae Molt into Adults
During this phase, the pupae molt and mature into adult flies. The pupal stage lasts from 9 to 17 days before the horn fly emerges as a small, black insect.
Day 18-40: Adult Horn Fly Emergence
After completing the pupal stage, the adult horn fly emerges. These adults are about 4 millimeters in length and can live anywhere from 2 to 4 weeks. The female adult then starts the cycle over again by laying eggs in fresh manure, and the process repeats itself.
The Problem of Infestations
Despite their relatively short life cycle, horn flies reproduce rapidly. In untreated herds, the population of horn flies can increase quickly, reaching infestations of up to 4,000 flies per animal. This level of infestation is not only uncomfortable for the cattle but can also lead to significant financial losses due to decreased weight gain and reduced overall herd health.
How Altosid® IGR Helps Control Horn Fly Populations
Altosid® IGR is an insect growth regulator (IGR) that passes through the animal and into the manure, where horn flies lay their eggs. It breaks the horn fly life cycle, preventing pupae from developing into biting adult flies. And unlike ear tags and sprays, there’s no need to round up or handle cattle because the animals spread the active ingredient as they graze. Altosid® IGR can also be fed to beef and dairy cows with no withdrawal times required before culling or milking, unlike some traditional horn fly control products.
While it is impossible to completely eliminate all flies from cattle, maintaining a fly control program with Altosid® IGR can help limit fly populations to under the economic threshold. With Altosid® IGR, producers can keep fly populations under control and reduce the stress and productivity losses associated with heavy fly infestations.
