Asian Mountain Hornets
Hello! I'm wondering if you have any ideas on how to prevent these big guys from taking over our peach, pear, and apple trees. I'm quite sure that's what they are, although I don't have a picture from our yard. Last year they decimated our fruit trees! Online sources said to destroy their nests, but I haven't been able to find any. Also, our peaches get "mummified" and it's not clear how to prevent that. First they are hard, the next day bruised-looking, and then they mummify. Any suggestions on either of these issues would be most helpful. Thank you!
Asian Mountain Hornets are not found here.
We assume you are talking about European Hornets? Take a look:
The bark stripping they do is usually minor and does no real harm to a shrub or tree. As you've noticed, it's not usually possible to know where their nests are. Additionally, they are considered beneficial because they eat pest insects.
In actuality, there are other insect pests and diseases that are regularly more of a problem for fruit growers here. In fact, it is difficult to grow what most consider 'good' tree fruit here without a careful management plan that includes precisely timed and repeated chemical applications of insecticides and fungicides.
Here is our tree fruit page that will get you started. http://extension.umd.edu/hgic/plants/tree-fruits Tree fruits are basically divided into is so-called stone fruits (those which have pits, like peaches and plums) and pomme fruits, like apples and pears.
The peach mummies you mention are a common major disease of stone fruits.
See here: http://extension.umd.edu/hgic/diseases-stone-fruit
Be very careful whenever you use chemicals to read and follow the directions to protect yourself, and the environment (especially don't spray when bees are active).