Indiana Department of Natural Resources sent this bulletin at 06/01/2023 07:25 AM EDT
Weekly Review for June 1, 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.
I finally went to investigate how bad the winter injury was on my button bushes and found a little surprise: fruit lecanium scale. The infestation is still relatively small and I was able to remove most of it by pruning, but I will add the button bushes to my list when I do my dormant oil spray on my fruit trees. Button bush is relatively large and is usually found in wet areas along streams and water bodies. It produces both pollen and a decent amount of nectar. It blooms in late June and early July and my bees go nuts for it. Button bush does fairly well in somewhat dry conditions, but as a wetland species, it thrives in moist sites.
Aphids have really taken off in the last couple of weeks. The columbine flowers in my yard are covered while a different species has found my spirea. Speaking of columbine, I noticed a touch of columbine leaf miner as well. Fortunately, columbine are tough as nails and about every plant I have is a volunteer!
On an inspection, I ran across false oleander scale on ‘Bracken’s Brown Beauty’ magnolia. It probably came from the grower with this problem, highlighting once again the importance of inspecting plant material when it is delivered. I have not run across this particular host/pest combination before, but Angela mentioned she sees it about every year farther south.
Finally, I visited a spongy moth site in Elkhart last week. It was interesting to watch the caterpillars fall out of the tree canopy on a strand of silk and get blown back to the tree trunk so they could hide in the crevices of the bark during the day. The caterpillars are between third and fifth instars. The variation in size was perpetuated by the lack of heat units in March causing egg hatch to be strung out over a week or so.
Regardless, warm conditions this week will accelerate feeding and the lack of moisture will add to tree stress. If you have spongy moth populations, time is running out to make effective treatments against this pest. Watch trees for signs of defoliation, be prepared to irrigate stressed trees if the dry spell persists into the fall, and prepare to take action next year.
