For 10 weeks starting in July, they gathered data from fruit fly traps in Yakama Reservation and Gifford Pinchot National Forest berry fields. But they also found six of them on the reservation, in an area closed to non-tribal members — the first official documentation of the fruit fly on Yakama Nation lands. A fruit fly trap set by the students on the Yakama Nation Reservation. The wasps lay their eggs inside fruit fly larvae, where they grow until they eventually overtake the fly’s immune system. Their work could also influence the national forest’s management of the fruit fly problem.