Friday, July 07, 2006

of all the gall

do two partial posts add up to one complete post? not really. so this is maybe 75 80% (see oops below) of a post.


wednesday we found thimbleberries (rubus parviflorus) with galls. hey. wayne at niches had a post about galls a bit ago, explaining that various insects lay eggs in various plants, and somehow cause the plant to form an enlarged, kinda cancerous looking bulge that houses, protects, and feeds the larva which hatch inside the gall. i grew up around white oaks and played with oak galls, or oak balls, as we kids called them, sometimes when throwing them at each other. they are very light. kinda like organic nerf balls. i had not, however, actually seen a larva in a gall. so i clipped off a thimbleberry vine with some galls and brought it in for inspection. a quick google informed me that the Diastrophus kincaidii wasp is the only insect to use thimbleberries thusly and it uses only the thimbleberry.

from the website of the salal chapter of the washington native plant society, in a piece titled "overwintering in the thimbleberries," by jay scott (scroll down a bit) he says, in reference to thimbleberry galls:

Dissecting the gall revealed the larvae and tunnels they had made through the plant tissue. Researchers have found this plant tissue rich in extra starch, glycogen, and protein. Outer layers of the gall contain tannin and phenolic compounds. The inside of a gall is therefore food for the herbivorous larvae. The outside is foul tasting armor against predators.

i sharpened a knife and sliced into the gall, expecting to find a pupa or larva. nada. just green stuff. oh well. i got another and sliced off thin slices, thinking i must have missed the critter in the first gall. still no indication of even an egg. this isn't very satisfying. not much of a post without a bug inside the gall.


galls on thimbleberry vines.

inside the gall.

oops! closer inspection of the photo above reveals this little guy, who moves when gently prodded. yikes. maybe all of the little cell-like things are nascent wasps.
science on-the-fly: abandoning early conjectures when presented with new observational information.
or,
lazy editing.
either way, there's the bug.

thursday wayne posted a piece on rust . the plant parasite, not iron oxide. i knew of rust as a plant disease, but thought it was a simple fungus. i learned that rust is a complex fungus that uses two hosts, alternating in a growth cycle between them. wayne, of course, provided a complete and fascinating description of two rusts, their life cycles and hosts, with pictures. when i went out to weed today i found a rust on a dandelion. shazam, i said to myself, here's a post. i took pictures. i'll just go google "dandelion rust" and have this wrapped up. well. not so fast. i found no references for dandelion rust. another partial post.


rust on a dandelion (hope i got that right)


dandelion flowers on another part of the rusty plant in the photo above.

a larger view of the flower.


enjoy the weekend. we'll be back monday. unless something amazing requires our commentary before then.

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