sweat bees and fruit trees

Asked March 11, 2020, 12:25 PM EDT

For two years in succession, my white peach tree fruit has been devastated by sweat bees; not one harvestable peach left on the tree. I know it is not any kind of animal because the stone remains attached to the branch wrapped in the dehydrated skin of the peach. I have not been able to see these sweat bees at work, but a friend had the fruit of his fig tree similarly devastated two years in a row. He did see the sweat bees at work. Can the sweat bees be controlled? How? In advance, thank you for your advice,

Baltimore County Maryland

3 Responses

The main food of sweat bees is pollen and nectar:
https://nature.mdc.mo.gov/discover-nature/field-guide/sweat-bees

It's possible that they will visit fruit when the normal amount of plants with pollen or nectar is too low or missing. Which would suggest planting more pollen and nectar sources. These bees are important pollinators that your fruit trees need.

If you have not seen any sweat bees on the fruit, it doesn't seem likely that sweat bees are actually your peach problem, since it would require massive amounts of bees and many visits to shrink up a peach.

However, peaches are highly susceptible to a fungal disease called brown rot which shrinks up a peach into what is known as a "mummy." We wonder if this is what you are seeing. Here is a page about brown rot (and other diseases of stone fruit): https://extension.umd.edu/hgic/topics/diseases-stone-fruit

For better photos of peach "mummies", search online images. If this is what you are seeing, the above link provides help.
You are also invited to send us photos of the shrunken fruit attached to a reply.

Ellen

I will look at the link for pictures of “mummies“ that you gave me. Attached is the picture of the mummies on my peach tree.

Brown Rot of Peach is the disease most likely to blame for your peach issues. Page 92 of this document https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/456/456-018/ENTO-336.pdf gives information and fungicide information for Brown Rot. Spraying will need to be started almost immediately (but probably best after the upcoming rains), as the flowering stage indicates this is the time to start protective treatments. Follow the interval directions on whichever brand you choose, as different fungicides will have different spray regimens. Several applications will need to be made to provide control, and it would help to remove all fallen fruit debris from last year to minimize fungal spread.

Miri