Why do these two creatures hang out with each other; GREEN JUNE BEETLES AND EMPEROR BUTTERFLY ?
August 23, 2009
I have seen in the past several weeks of August both the green june beetle and the emporer (hackberry Monarch) Butterfly hanging out with other in groups on several of our trees. Why are these two insects drawn to each other? What are they doing?
Also there is a third beetle that I have never seen before either. What is it? It is large and scary looking but seems to not be welcomed by the green junebug and butterlflies but still tries to hang out in the area that they are. I saw only the one new beetle at 6:30 in the evening.
These insects are all feeding on sap that is oozing from the tree. Perhaps the tree was injured or perhaps there are boring insects that are causing sap to ooze. Emperor Butterflies in the genus Asterocampa as well as many other butterflies do not strictly take nectar from flowers. According to BugGuide, the Hackberry Emperor, Asterocampa celtis: “Adults take sap, fluids from dung, carrion, etc. Like the Tawny Emperor, very fond of taking sweat from humans.“ Regarding the Green June Beetle, Cotinis nitida, BugGuide indicates adults eat: “Pollen; ripening fruits, especially peaches; and the fruit and leaves of many shrubs.” Your unidentified beetle is an Eyed Elater, Alaus oculatus, and BugGuide indicates: “Adults may take some nectar and plant juices.” Your photos document an interesting gathering of insects at a shared food source and it is wonderful since sap is not indicated as a food for either the June Beetle or the Eyed Elater.