I am pretty sure we have a problem with this pest on our very old (and half rotten) Cherry tree. I posted about 1 month ago and this was suggested, I have since found pictures of the worm and am convinced this is what we have as I have seen the worm and the adult around the property. I am hoping to get some advise on what to apply and how to apply it. This tree is very tall..
BtK is normally prescribed. wait till you see the start of damage then apply to as much as possible of the tree, wait a week and check for new damage or live beasts, if present, apply again.
If your tree is very large.... You may have a hard time spraying it. In late summer there is also another option for Span Worm control by banding the tree with a product called Tanglefoot. Won't help you this year though. Please note that if your Cherry tree had holes in the leaves all summer long, you may have bigger problems then a few span worms. Span worms are gone in June, while your tree produces many more leaves long after they're gone, covering up the leaves with holes. What I am getting at is if Span Worms are the tree's only concern, then by mid July all should start to look somewhat fine again. Does it? Jim.
Thanks Jimmyq, I will look into the solution you recomended. Much appreciated. Jim weed, last year the tree looked horrible. I remember the early summer well but I suppose I could have selective memory and am assuming it lasted through to fall... What I do remember is the skelton look of the leaves last year, all of them it seemed.. this was all in the spring or early summer shortly after they developed. The tree has / had a lot of rot as well, I believe it has lived a long life. My Neighbour remembers when our home was built in 1955 and states the tree was here then and believes it is part of an ariginal orchard. It is possible it is on its last legs. I cut much of the dead and rotten branches off a year + ago. There are still a couple larger sections that I should remove but have not done so. I would like very much to save the tree as it adds much character to our back yard.
Scottq, BTK as Jimmyq mentioned is a biological insecticide. It comes as a powder and needs to be added to water. For optimum control you need to be able to cover all the leaves with this product. As the Span Worms eat the leaves they must ingest the BTK in order to kill them, it takes only about 24hrs for death to start to occur. Mind you though heavy over night dew or rain will wash the product off the leaves, then it must be re-applied if control is not achieved. It is sometimes easier to apply the banding in the late summer to the trunk where you can reach. The female moth from the Spanworm is wingless, and must climb the tree in order to lay her eggs in the fall. It is suggested in almost all literature to apply the banding in Oct, not true! It is important to get the banding on in late Aug! If it is going to be done at all. Kind of sounds to me that your tree has more serious health issues then Spanworm problems, although they may be present during the spring, it's not that common they do too much serious damage. Are the branches long and spindly with the majority of the growth on the tips, and the leaves are skeletonized looking with mostly the veins holding them together, any brown dead clumps of leaves hanging on all summer? I am sorry I could go on all day with Cherry tree problems around here. Other things to google, could be: brown rot, shothole, bacterial blight. Unfortunately the biggest and newest problem doesn't seem to be getting much attention yet, summer drought stress, and from my experience is now the largest cause of holes in foliage! Best of luck with your tree,, Jim.
