Impact of Abrostola asclepiadis combined with other stressors on invasive swallow-worts (Vincetoxicum species)

Publication date: Available online 16 November 2018Source: Biological ControlAuthor(s): Lindsey R. Milbrath, Jeromy Biazzo, Antonio DiTommaso, Scott H. MorrisAbstractThe moth Abrostola asclepiadis (Lepidoptera: Noctuidae) is being investigated for the biological control of pale and black swallow-wort (Vincetoxicum rossicum and V. nigrum, respectively; Apocynaceae), European vines introduced into North America. Limited information existed on its potential impact on swallow-worts, and the combination of defoliation damage by A. asclepiadis and other stresses to the plants had not been studied. We conducted greenhouse studies of the impact of different frequencies (once or twice) and degrees of defoliation (50 or 100%-seedlings; one or two larvae per stem-mature plants) by larvae on seedlings and mature (flowering) plants of black and pale swallow-wort. Defoliation was combined with varying light levels (shaded or not) or competition with quackgrass (Elymus repens). Significant reductions in aboveground dry mass and seeds generally only occurred when plants were completely defoliated twice. Grass competition and, to a greater extent, shading reduced growth and reproduction of swallow-wort plants. However, no interactions between defoliation and the other stressors occurred, suggesting they would have an additive effect. Because A. asclepiadis will likely be univoltine if it were to be released in North America, its impact appears to be limited even if severe defoliation could be...
Source: Biological Control - Category: Biology Source Type: research