Indiana Department of Natural Resources sent this bulletin at 05/24/2023 07:20 AM EDT
Weekly Review for May 24, 2023
This informal report by the Division of Entomology & Plant Pathology is a commentary on insects, diseases, and curiosities division staff encounter on a week-to-week basis. Comments and questions about this report are welcome and can be sent to your respective Inspector.
Spotted lanternfly began hatching in Huntington on Thursday, May 18. They will likely be emerging over the next several weeks depending on if the egg mass was laid in a cooler environment, such as the shady side of a tree, or a warmer spot like the south side of a building.
This past week I was called by a beekeeper who had lost a hive over the winter and was worried that they had a disease issue. Looking at the dead hive I found some wax moth damage, but no signs of any disease issue. I started to inquire about their mite treatment protocol and found that they were using oxalic acid vapor in September. I recently attended a bee meeting where late season mite treatments were discussed quite a bit. I encourage beekeepers to start thinking about varroa treatments after you harvest your honey. Mites cannot keep up with the queen during the population increase phase, but once the flow slows down and the colony cuts back on rearing brood, that’s the point when the mite population continues to climb. If you are waiting until the fall to treat for mites, your winter bees are already going to be damaged from varroa. Treating at that point is too late.
Photo 4- Varroa population model produced by Randy Oliver – Scientificbeekeeping.com (used by permission)
Also, this past week I noticed the first tulip poplar in bloom on May 18, which was right around 515 growing degree days (GDDs). Black locust, which started blooming on May 10, gets the majority of the attention in my area, but tulip poplar is also quite attractive to honeybees and shouldn’t be overlooked. It also happens to be the state tree of Indiana!
I’ve been trying to get to dealers over the last week or so. Frequent finds include spider mites on tropical plants from Florida, aphids on hibiscus, and occasionally black spot or viruses on roses. The take-home message is to inspect plant material as it comes off the truck or at least set it aside until you can look it over.
These wooly beech aphids on Dawyck Purple beech are just such an example. These trees were pulled off the truck and put directly into the nursery. Fortunately, wooly beech aphids feed only on beech, so they are not a major pest, but the new trees were placed among beech already at the nursery. So now, due to the chance of spread, all the beech in that section needed to be treated rather than just the handful of trees just delivered.
