Welcome to austinagrodolce … My family and I garden with more intention and enthusiasm than allocated budget or overall design plan. It shows. Wildlife populations don't seem to notice our lack of cohesive design, they just like the native plants here. It seems by growing local we've thrown out a welcome mat. Occasionally, we're surprised at who (and what) shows up.
Sunday, May 4, 2014
And not just one. After I saw the first one and moved closer to investigate, I discovered 6-8 mystery balls on a couple of volunteer red oaks out back. They weren't seed balls - oaks make acorns - they weren't fruit - I knew that much - but I had no idea what they were. A little time on the internet and the mystery was solved.
These are oak galls, a response of the leaves of the plant to the stimulation of a gall-provoking insect in the larval stage. Red oak galls are caused by the oak apple gall wasp (Amphibolips confluenta) so named because the largest round spongy balls look like lumpy apples on the tree. Ours are smaller - more golf ball sized.
Of course I broke one open - I "had to" for research purposes. The balls are filled with spongy fibers and actually crumble somewhat disconcertingly. There was "something" in the middle (apparently the larvae) and it looked like it moved. At that point I got the willies and unscientifically tossed my research subject aside.
Then I went inside and washed my hands. Twice.
According to the interweb, leaf galls won't kill a tree though in numbers they can cause early leaf drop. The wasps don't sting humans (an admirable quality) and the vacated galls (those not dropped abruptly to the ground) often host other beneficial insects.
PS: I visited my go-to site for all things buggy (BugGuide) and discovered my trusted experts did not have one single image available for the oak apple gall wasp. Gasp! Challenge, accepted...