Susceptibility of Native and Non-Native Common Reed to the Non-Native Mealy Plum Aphid (Homoptera: Aphididae) in North America

• Published in: Environmental entomology 2007-04, Vol.36 (2), p.451-457
• Main Authors: Lambert, Adam M, Casagrande, Richard A
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Aphids - growth & development; Autoecology; Biological and medical sciences; ecological invasion; Ecosystem; Female; Fundamental and applied biological sciences. Psychology; genetic resistance; Haplotypes; host plants; Hyalopterus pruni; indigenous species; indirect interactions; introduced plants; introduced species; invasive species; Male; North America; Pest Control, Biological - methods; pest resistance; Phragmites australis; plant competition; plant damage; plant-insect relations; Plants and fungi; PLANT–INSECT INTERACTIONS; Poaceae - genetics; Poaceae - parasitology; Population Density; Population Dynamics; Species Specificity
• ISSN: 0046-225X; 1938-2936
• DOI: 10.1603/0046-225X%282007%2936%5B451%3ASONANC%5D2.0.CO%3B2

An aggressive, non-native haplotype (distinct genetic lineage within a species) of Phragmites australis is invading brackish and freshwater systems in the eastern United States, potentially displacing native haplotypes. We studied the differential susceptibility of native and non-native populations collected from sites throughout North America to the non-native aphid, Hyalopterus pruni. In a greenhouse study, we found significantly higher aphid populations on native haplotypes than on the non-native haplotype 2 mo after infestation. Aphid feeding caused chlorosis and death of native stems, and in some cases, killed whole native genets. The non-native plants remained relatively undamaged. In a field study, non-native plants had significantly lower aphid densities than native plants or remained aphid free. There was an interactive effect in which aphid populations increased on the native plants over the 1-mo study period but remained low on non-native plants over the same period. The susceptibility of native North American populations of P. australis to non-native aphid infestation may indirectly affect the ability of these native plants to compete with non-native plant populations, ultimately contributing to the decline of native haplotypes.