I'm new to beekeeping. In April, I started 4 hives: 1 from local bees that were removed from a person's house, 1 from a swarm that came a few weeks later from that first hive, and 2 hives from purchased Saskatraz packaged bees. I see bees from time to time in front of the Saskatraz hives that have deformed wings. These wings don't look anything like the pictures on the web. Instead of looking malformed, the wings are perfectly symmetric but very short (maybe 1/2 of normal length).
I know that deformed wings are often caused by a virus carried by varroa mites. In theory, the mite load in my hives should be very low, since these are new hives and the mites haven't had much time to reproduce inside the hive. Also, I have trays containing vegetable oil under all my bottom screens. I saw dead hive beetles in those trays for a few weeks in July (the oil trays seemed to totally eliminate the beetles), but I have never seen a single varroa mite in the oil trays all year. That would see to say that I don't have many mites.
Any idea why I'm seeing short wings on some of the bees? I guess the packaged bees could have had the virus when I received them, but why would I see only short wings and not malformed wings?
Thanks,
Curt