Vet Patricia van Veen from Zoetis said warm and wet weather provides optimum conditions for the overwintering of flies and the acceleration of maggot development. Ms van Veen suggests the most effective control method is a two-step approach, using spot-on products or long-acting fly control ear tags, alongside environmental management to control fly breeding sites. Spot-on products like Fly & Lice Spot On® and DYSECT® and long acting fly control ear tags such as the Flectron® tag will help safeguard stock. So, keeping stock away from fly breeding sites like wet and muddy areas can help reduce the risk," she said. FLECTRON FLY EAR TAGS FOR CATTLE 935 MG contains cypermethrin.