Native generalist natural enemies and an introduced specialist parasitoid together control an invasive forest insect.

Autor: Broadley HJ; Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, USA.; Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA., Boettner GH; Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA., Schneider B; Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, USA.; Biology Department, Merced College, Merced, California, USA., Elkinton JS; Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, USA.; Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA.
Jazyk: angličtina
Zdroj: Ecological applications : a publication of the Ecological Society of America [Ecol Appl] 2022 Dec; Vol. 32 (8), pp. e2697. Date of Electronic Publication: 2022 Aug 16.
DOI: 10.1002/eap.2697
Abstrakt: Specialized natural enemies have long been used to implement the biological control of invasive insects. Although research tracking populations following biological control introductions has traditionally focused on the impact of the introduced agent, recent studies and reviews have reflected an appreciation of the complex interactions of the introduced specialist agents with native generalist natural enemies. These interactions can be neutral, antagonistic, or complementary. Here we studied the invasive defoliator winter moth (Operophtera brumata) in the Northeast USA to investigate the role of native, generalist pupal predators along with the introduced, host-specific parasitoid Cyzenis albicans. Prior research in Canada has shown that predation of winter moth pupae from native generalists increased after C. albicans was established as a biological control agent. To explain this phenomenon, the following hypotheses were suggested: (H 1 ) parasitoids suppress the winter moth population to a density that can be maintained by generalist predators, (H 2 ) unparasitized pupae are preferred by predators and therefore experience higher mortality rates, or (H 3 ) C. albicans sustains higher predator populations throughout the year more effectively than winter moth alone. We tested these hypotheses by deploying winter moth pupae over 6 years spanning 2005 to 2017 and by modeling pupal predation rates as a function of winter moth density and C. albicans establishment. We also compared predation rates of unparasitized and parasitized pupae and considered additional mortality by a native pupal parasitoid. We found support for the first hypothesis; we detected both temporal and spatial density dependence, but only in the latter years of the study when winter moth densities were low. We found no evidence for the latter two hypotheses. Our findings suggest that pupal predators have a regulatory effect on winter moth populations only after populations have been reduced, presumably by the introduction of the host-specific parasitoid C. albicans.
(© 2022 The Ecological Society of America.)
Databáze: MEDLINE
Externí odkaz: