PARENT SESSION
Poster Session 34: Herbivory
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Reproduction success of Hyalopterus pruni Geoffr. on native and introduced genotypes of the invasive plant Phragmites australis in NA.
Eichiner, Florian,
ABSTRACT- P. australis and the newly described subspecies P. australis americanus occur as introduced and native reed species in NA. We used different genotypes of native and introduced P. australis to look at the reproduction rate of the mealy plum aphid Hyalopterus pruni. The holocyclic aphid uses P. australis as the secondary host amongst other grass species. We used potted plants grown for over one year in the common garden at the Resource and Ecology Management Laboratory (REM) at Cornell University. When aphids were found to migrate from a nearby orchard to our common garden we collected apterous adults for mass rearing. We kept them on leaves of separate P. australis plants in attached leightweighted cages for protection against predators and parasitoids. As soon as enough apterous adults were reared we transferred adults on the experimental plants. These plants were kept randomly assigned in a 4 m by 4 m watered pond to ensure constant water supply. We used seven native and five introduced populations from NA with 2-5 replicates depending on available plant material making a total of 54 potted plants. One adult per plant was transferred on a caged leave using a paint-brush and left for 7 days. Then leaves together with cages were cut of the plant and frozen to allow better counting of the aphids. The mean reproduction rate of aphids was 20.2 individuals for all native and 21.8 for all introduced genotypes. But the mean in between the individual genotypes for native and introduced P. australis varied from 15.4 to 35.5 for native genotypes and from 9.0 to 29.6 for introduced genotypes. That indicates that there is a selection for genotypes by the mealy plum aphid.
Key words: Phragmites australis, Hyalopterus pruni, Reproduction, Genotypes