This berry plant has a lot of gall

Thimbleberries are good to eat

Almost every plant has a gall on its stem

Inside the galls are the larvae of a parasitic wasp

One of the most numerous and conspicuous plants in the bush around here is the Thimbleberry or Rubus parviflorus. It produces enormous maple-shaped leaves, pretty white flowers in the spring and now, in late-summer, tasty red berries.
There are only a few of the raspberry-sized berries on each plant but they are extremely easy to pick since they are two-to-three feet off the ground.
Just as noticeable as the thimbleberries, however, are the abnormal growths on the plant stems. These bulbous galls often resemble a fruit themselves but in fact they are the result of parasitic wasps.
Diastrophus kincaidii wasps lay their eggs in the stems and when the larvae hatch they feed on the starchy tissue. The plant reacts by building the stem around the grubs thus forming the gall.
Just about every thimbleberry plant here in Nolalu has at least one gall and some have several.
I haven't seen it but there is yet another parasitic wasp that lays its eggs inside the larvae of the first wasp. The wonders of the bug world!
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