Indiana Department of Natural Resources sent this bulletin at 05/12/2021 07:55 AM EDT
Weekly Review for May 12, 2021
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.
This cooler weather will slow down swarming. Once we get back in the 70’s more swarms are likely. We are getting more requests from beekeepers to be added to the DNR swarm list.
A bothersome trend I have seen this spring is beekeepers without enough honey supers ready. For every hive that makes it through the winter, you should have 2 or 3 honey supers ready to put on this spring. These should have been prepared this winter. At least one honey super should be on the hive right now. A strong hive could have 2 honey supers on now and be ready for the 3rd super.
If you split your strong hive now, it needs to be a strong split with lots of bees that can cluster around the brood. They will need to cluster on these cold nights. You need to track the nighttime temperatures, not the daytime temperatures. As nighttime temperatures get steady in the 50’s and up, you can do more with the hives and worry less about chilling brood.
I had a beekeeper wanting to put a new frame of foundation right in the middle of brood frames. This is done to give the queen room to lay also get the foundation drawn out. Once the bees draw it out the queen should jump on that new comb and start laying eggs. We can do this when the nighttime temperatures are in the 50’s. Have patience and wait until June to do this.
The nucs I looked at last week were ready for beekeepers to pick up. The nuc producer started these from frames from hives that went to California for almond pollination. The queens were grafted in April by putting the caped queen cells into nucs with some frames of brood and bees from the California hives. They just had to wait for the queens to hatch and start laying a good pattern. Now they have to get them out to beekeepers before the nucs get too crowded.
Autumn Olive is blooming now. This is an invasive bush, but it is great nectar source for bees.
Ken Cote (Nursery Inspector & Compliance Officer) - KCote@dnr.IN.gov
The pest season continues to be delayed and off to a slow start. However, I finally found a few aphids species this week. I found very early stages of woolly birch aphid on river birch. Look for bumpy leaves and woolly masses on the undersides of leaves. I also found Balsam twig aphid on Alberta spruce. This is a minor pest that usually infested new growth and causes needle twisting. I frequently encounter this pest in garden centers early in the season, but damage is rarely serious. Look for white aphids feeding on terminal and new growth. Two spotted spider mites were found on butterfly bush that had been grown in a greenhouse and moved outside.
Look for fine stippling and leaf yellowing. Large population levels can cause webbing and leaf browning. These mites occur on the undersides of leaves which can make them difficult to treat. They are a warm season mite with a wide host range and can have multiple generations per year. If you have this mite on your plants in spring, I recommend treating them early on because the problem will only get worse later in the growing season. During an inspection I found pine bark adelgid on eastern white pine. This pest appears as white cotton material that exist primarily on the bark of branches and trunks of white pine. It typically infests older trees and usually does not cause serious problems at low population levels, however it can look unsightly to customers. This pest should not be confused with the hemlock woolly adelgid which feeds at the base of hemlock needles and cause plant death. That is a pest we are trying to keep out of Indiana.
I am not seeing many disease problems at this time. Some leaf spot diseases are just starting to become an issue on certain hosts. I have not yet seen cedar apple rust or fire blight symptoms on apple trees. Many garden centers are busy right now and I have encountered locations that are not properly untying plants or leaving them on shipping boxes too long. This is resulting in new growth that is yellowed in appearance. Remember to separate plants to give them good light and air circulation. This will prevent physiological and disease issues associated with overcrowding plants.
I did some dealer inspections in Allen and Dekalb Counties this past week. I saw some frost injury on sensitive plants, but most of the material coming in appears to be fairly free of insect and disease problems so far. I did find some two-spotted spider mite damage on butterfly bush and a few aphids feeding on the buds of ‘Double Knockout’ rose.
