Pemphigus betae

Pemphigus betae

As with most host-alternating aphid species, the sugarbeet root aphid is restricted in its primary host range, but the secondary host range is more diverse. Pemphigus spp. prefer poplars in the genus Populus (Fig. 2) as their primary hosts (Blackman and Eastop 2006). Over the years, P. betae primary hosts have been identified as species within the Populus section Tacamahaca, including narrowleaf cottonwood (P. angustifolia James), balsam poplar (P. basamifera L.), and black cottonwood (P. trichocarpa Torr. & A. Gray) in North America (Parker 1915, Harper 1963, Whitham 1978, Floate et al. 1997, Dewar and Cooke 2006, Hein et al. 2009). Although there is some overlap in their geographical distribution, these primary hosts occupy relatively distinct regions in North America. For example, narrowleaf cottonwood is found primarily in the central and southern Rocky Mountain regions, the balsam poplar is found in the northern Rockies into Canada and extending east to the Great Lakes region, and the black cottonwood has a range stretching from Alaska, through western Canada, and primarily into the northwestern United States, but also sporadically down as far south as Baja, CA (U.S. Department of Agriculture [USDA] 2014). Additional ecological complexity of these aphid–primary host relationships was demonstrated by Floate et al. (1997) who found a dramatic increase in P. betae host acceptability for hybrids between the aphid’s primary hosts and other Populus spp.

Ecology and management of Pemphigus betae (Hemiptera: Aphididae) in sugar beet