U.S.-Japan Cooperative Science: Impact of Introduced Lady Beetles on Prey and Other Predators in Both the Old and New World

Utah State University, Logan UT

Investigators

Abstract

0089374 Evans This award supports a three-year collaborative research project between Professor Edward Evans of the Utah State University and Professor Hironori Yasuda of Yamagata University in Japan. The researchers will undertake a study of the impact of introduced lady beetles on prey and other predators in both the old and new world. Species invasions around the globe are accelerating, in part from purposeful introductions by humans as in the practice of biological control. Through effects on biodiversity of invaded communities species invasions may have fundamental consequences for ecosystem functioning. Diversity often provides an important stabilizing measure of species redundancy within ecosystems, wherein reduced activity by a single species is counterbalanced by compensatory responses by other species. Predators introduced to enhance biological control may compromise the capacity for species redundancy in prey suppression if pre-existing predators are driven to low numbers or extinction. The researchers will study two invasive lady beetles in particular (Coccinella septempunctata and Harmonia axyridis) both in their native Japan where they have coevolved with other predators attacking aphids, and in Utah, where they now interact with native North American lady beetles and other aphid predators. They will attempt to determine the degree to which assemblages of predators (either longstanding and coevolved, or newly created are characterized by species redundancy in their capacity to reduce prey. They will also assess the root causes and consequences in habitats such as alfalfa of declining diversity of native lady beetles in North American associated with the establishment of Old World lady beetles. The project brings together the efforts of two laboratories that have complementary expertise and research capabilities. Results of this research should enable the researchers to address whether and how invasive insect predators may alter basic predator-prey relationships in invaded communities. This research advances international human resources through the participation of graduate students. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. The researchers plan to publish results of their research in scientific journals and report on the findings at scientific meetings.