| phylogenetic and molecular evidence for allochronic speciation in gall-forming aphids (pemphigus). | sympatric populations can diverge when variation in phenology or life cycle causes them to mate at distinctly different times. we report patterns consistent with this process (allochronic speciation) in north american gall-forming aphids, in the absence of a host or habitat shift. pemphigus populi-transversus riley and p. obesinymphae aoki form a monophyletic clade within the north american pemphigus group. they are sympatric on the eastern cottonwood, populus deltoides (salicaceae), but have di ... | 2004 | 15119438 |
| spatio-temporal patterns of mortality in pemphigus populicaulis and p. populitransversus on cottonwoods. | galls of the aphid species pemphigus populitransversus and p. populicaulis from a single cottonwood in clinton, new york were censused for mortality approximately every ten days during the summer of 1978. p. populitransversus had significantly higher survival than p. populicaulis. both species of aphid showed considerably elevated mortality later in the season. mortality was not spatially random, but neighboring galls had a tendency to die at close to the same time. this tendency to spatially au ... | 1985 | 28311563 |
| extraction from soil of apterous pemphigus populitransversus (hemiptera: pemphigidae) feeding on cruciferous vegetable roots. | the poplar petiolegall aphid, pemphigus populitransversus riley (hemiptera: pemphigidae), is a gall-forming aphid attacking leaf petioles of populus spp., its primary hosts. its secondary hosts are the roots of cruciferous (brassicaceae) plants, where it is also commonly known as the "cabbage root aphid." the apterous forms are destructive pests of cruciferous vegetables in many parts of the world. in our experiments, the root-feeding apterous forms were extracted from the soil using a berlese f ... | 2011 | 21735937 |
| changes in microgeographic variation patterns of pemphigus populitransversus over a six-year span. | | 1971 | 28565028 |