Egg laying can be reduced by placing a sticky grease band or barrier glue around the trunk and tree stake in October to intercept the females. This needs to be kept sticky and free of detritus until mid-April. Many birds, especially tits, feed their chicks with large numbers of winter moth caterpillars during the spring.
Shortly after bud burst - but not during flowering due to the danger to pollinators - apples, pears and small ornamental trees can be sprayed with deltamethrin (e.g. Bayer Sprayday Greenfly Killer) or lambda cyhalothrin (e.g. Westland Resolva Bug Killer), provided the label instructions relating to the food plant are followed.
An organic alternative is pyrethrum (e.g. Py Spray Garden Insect Killer, Bug Clear Gun for Fruit & Veg) to control the young caterpillars. Caterpillar damage on tall trees has to be tolerated.
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)