Just like that, we’re in March and the fly season is ahead of us yet again. In certain areas last autumn the flies were out in force and at that point, they’d had all season to build up their population numbers. Now is the time to get ahead to prevent that happening this year if we’re going to have a similar summer, weather-wise.
The main types of flies in UK herds are the stable, horn, house, face, and head flies, all carrying a different threat, however, control methods remain the same.
Diseases, such as New Forest disease (infectious bovine keratoconjunctivitis) and summer mastitis can be transmitted via flies. New forest disease for instance, is an eye infection caused by Moxarella bovis, transmitted by face flies. This causes extreme pain to the eye and increases the need for antibiotic use. The cost of a case of summer mastitis is estimated to be at £250-300 per case (AHDB), but true costs can vary. A maiden heifer with an undiagnosed case of summer mastitis
may lose a quarter, reducing her overall productivity potential and immediately decreases any resale potential if you were to sell her as a milking heifer.
Then we must also consider the costs of constant irritation leading to a reduced feed inefficiency and weight loss or reduced milk yields.
Our clover friendly flies are becoming increasingly popular and are a useful addition to your fly control programme, so what are they and why should you be using them?
Traditional fly control has involved pour-ons (Deltamethrin products, such as Swish or Spot on) and Permethrins (fly sprays), along with fly traps, strings and our Sheila boards (Sheila pheromone that attracts adult flies). Whilst this reactive approach to fly control is still a useful tool, and should be used in a combined approach to fly control, we are seeing an increased resistance to deltamethrin and permethrin products.
Our clover friendly flies are a proactive approach to fly control. These are parasitic wasps which parasitise fly larvae. They are UK native species, grown in insectaries. These tiny nonnuisance parasitic wasps are a method of biological fly control, they are environmentally friendly, sustainable and importantly have no resistance. This being said, because both the fly population and the parasitic wasp population reproduce so quickly, there should never be any resistance.
The benefits of friendly flies are huge because target the fly larvae.
Adult flies are only the tip of the iceberg and only 15% of the problem, the problem that we target with our reactive fly control approaches. With
this approach, we leave 85% of the problem untouched, able to hatch out, and cause a nuisance as adult flies. Our friendly flies are able to target the 85% of the problem we don’t see and think about, and therefore should reduce the overall fly population, particularly if used as a combined approach in the early years.
The friendly flies with parasitise around 90% of the larvae available to them. They don’t completely eradicate the population as they need flies and the fly lifecycle to be able to replicate themselves.
Our VetTechs are able to spread the clover friendly flies for you in your problem areas, all included in the price. Distribution takes place fortnightly between March
to November. Topping up the population, so the flies don’t get ahead of the parasitic wasps due to the shorter lifecycle of the flies. We estimate that our bags will do around 50 head, although this varies between farms and is dependent on farm size, cleanliness and the severity of the fly problem.
We’re holding an online meeting on Thursday 17th March to discuss 2022 fly control. Please get in touch if you would like some further information or a visit.