Sure, blackberries are delicious, and for a brief period in the late summer, everyone has a free snack on their trails, but surely, there must be some negative consequence of the blackberry invasion. One of the primary concerns when it comes to blackberry recruitment is the competitive exclusion of native flora. The Himalayan blackberry is a voracious competitor for water, nitrogen, and sunlight. According to the scientific literature, it is particularly good at colonizing disturbed habitats, particularly human-mediated disturbances. In addition, it escaped disease associated with the Eurasian fungal rust (Phragmidium violaceum), which it left behind in its native region. Prevalence in disturbed habitats and escape from native enemies are not uncommon attributes of highly invasive taxa. It has also been suggested that some biological invasions can facilitate the establishment of future invaders…
Enter: the spotted wing Drosophila
If rampant blackberry cane growth weren’t enough of a problem, meet Rubus armeniacus’ partner in crime: Drosophila suzukii, otherwise known as the spotted wing Drosophila. Also invasive in North America, the spotted wing Drosophila originated in east Asia where it largely infests stone fruits along with other fleshy fruits. So when this fruit fly made it across the Pacific and had to lay its hungry little offspring into an energy source, in addition to the bountiful crops of the Pacific Northwest it had all the invasive blackberries. An article in the Oregonian featured the spotted wing Drosophila and indicated its use of Himalayan blackberries as a “super highway” up and down the Pacific Northwest. In spite of efforts in the agricultural community to eradicate the fruit fly, it can utilize the unsprayed Himalayan blackberries as a host and is thus potentially here to stay.
Still hungry for more?
Check out this New York Times article written by a fellow blogger about Himalayan blackberries.