Butterfly and Ants on Oak Gall
Location: Iowa, United States
April 21, 2012 4:53 pm
I thought you might like this interesting picture of a painted lady butterfly on an Oak gall along with many ants. Whenever an ant left, its abdomen was a lot bigger than when it got there! You can’t see in the first picture, but in the second one you can see how some of the ant’s abdomens are full of sap (the ant on the tree branch to the right of the gall).
Signature: Michelle Lynn
Your photo is quite fascinating, but a few corrections are in order. The butterfly is in the “Lady” genus Vanessa, however it is actually the Red Admiral, Vanessa atalanta. You can compare the under side of the wings to this photo from BugGuide. Many butterflies and indeed other insects are known to feed on oozing sap. We don’t believe this is the result of a gall. We don’t know what is causing the formation in the photo, but is doesn’t appear to be an insect gall to us.