Blueberry stem gall wasp
Blueberry stem gall wasp (Hemadas nubilipennis) cause swellings (galls) on canes at egg deposition.
Swellings first appear greenish to red in color. Older galls appear gray and corky and often have exit holes.
![Blueberry stem with three lumpy, egg-shaped galls. Two galls are bright red and shiny. One gall is lumpy, dull gray, and has multiple pin-sized holes.](https://blogs.cornell.edu/berrytool/files/2016/12/bb105-stem-gall-opt-140ptel.jpg)
Larvae overwinter in galls then emerge as adults in spring.
![Cross-section of corky gall showing multiple internal chambers. One chamber has a cream-colored sphere inside of it.](https://blogs.cornell.edu/berrytool/files/2016/12/bb106-stem-gall-opt-1trqhu5.jpg)
![Close-up of a curled, translucent larva inside of a frass-lined tunnel. Larva has no discernible limbs or features.](https://blogs.cornell.edu/berrytool/files/2020/09/cynipic-gall-wasp-larvae-closeup_MConcklin-300x225.jpg)
![Blueberry branch with cluster of blossoms, leaves, and large dark corky mass situated above blossom cluster. A black wasp the size of a pinhead is perched atop the black gall.](https://blogs.cornell.edu/berrytool/files/2020/09/stemgall2-e1601391427959-300x227.jpg)
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