If you would like to reduce the harmful effect of caterpillars in the early spring, munching away on the newly-appearing blossoms and young fruitlets, without applying chemicals and insecticides, then grease bands are an old-fashioned but highly effective method.
Grease bands are based on the principle that the females of various insect species are wingless and begin to crawl their way up the tree, via the trunk or low-hanging branches that brush the ground. The stake next to the tree may be used as a route to climb into the tree.
The pests I am referring to are the larvae of the Winter Moth, the Mottled Umber Moth and the Vapourer Moth. These larvae, once they have arrived at their destination, will begin to deposit their eggs around the fruit buds and in the crevices of the bark all over the tree. No damage occurs this time of the year.
When the winter has passed and the temperatures begin to increase, then the eggs of the larvae will produce lots and lots of little caterpillars. These will begin their munching feast on all that freshly-appearing green foliage. Then, worse still, once blossom time is over, they will then start chomping away at the young fruitlets just as they are appearing.
It is in early-mid October that the larvae of those insects begin their journey from the soil into the trees. If applied correctly, the grease bands will trap them. Follow the instructions on the packet. Any good garden centre stocks them at that time of the year. Keep your grease bands in place through to the end of April as in the spring other insects will also try to climb into the tree for the same purpose. Grease bands are therefore very valuable not only at this time of the year but also during warm days in the winter and the spring, repelling all sorts of creepy crawlers. Remember to attach them to the stake as well.
To tell the truth, I have only ever used grease bands of the type in which the sticky stuff is on sheets of plastic, so that the grease itself is not in contact with the trunk. There are types of grease sold in tubs that can be applied direct to the trunk of your fruit trees, as shown in the photo. Perhaps someone could tell me about their experience on this. In any case, another thing that should be done at this time for the same reason is to cut the low ground-touching branches back to at least 18 inches above soil level.