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

• Main Authors: Broadley, Hannah, Boettner, George, Schneider, Brenda, Elkinton, Joseph
• Format: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: Cyzenis albicans; Operophtera brumata; parasitoid; winter moth; FOS Biological sciences; Arctic; Fennoscandia
• Online Access: https://dx.doi.org/10.5061/dryad.1g1jwstrt; https://datadryad.org/stash/dataset/doi:10.5061/dryad.1g1jwstrt

Specialized natural enemies have long been considered a major force driving the population dynamics of outbreaking forest insects. While research has traditionally focused on the role of specialist parasitoids, recent studies and reviews reflect an appreciation of complex interactions among many regulatory factors. The sources suggest that specialist parasitoids and generalist predators can each inflict strong top‐down effects and that specialists and generalists can interact to regulate insect herbivore populations. Here we use the model study organism winter moth (Operophtera brumata) in its invasive range in the northeast United States to investigate interactions between the introduced, host-specific tachinid parasitoid Cyzenis albicans and native, generalist pupal predators. Prior research in Canada showed that predation of winter moth pupae increased after C. albicans establishment. To explain this phenomenon, the following hypotheses have been suggested: (1) parasitoids suppress the winter moth ... : Study organisms Winter moth, Operophtera brumata L., is a geometrid moth native to Europe and northern Asia and can be an important defoliator, particularly in its invasive ranges in coastal North America (Nova Scotia, British Columbia, and New England) (Roland and Embree 1995, Elkinton et al. 2015) and in sub‐arctic birch forest in northern Fennoscandia (Jepsen et al. 2008). Winter moth caterpillars hatch in synchrony with bud-break of their host plants, a broad range of deciduous trees, particularly oak and maple. The caterpillars feed on the foliage in early spring before dropping to the soil in mid-late May to pupate. Winter moth has a long pupal period (6–7 months during the summer, representing most of its life) and it pupates in the top layer of soil or leaf litter. They emerge as adults in early winter, from early November through early January at which point they mate and lay their eggs in bark cervices. These eggs overwinter and the cycle repeats with one generation per year. Cyzenis is a tachinid ...