Fruit flies take over California

Despite officials’ best efforts to rid California of invasive fruit flies, the pests are here to stay. That’s the conclusion of a new report in Proceedings of the Royal Society B, which says five to nine species are now established in the state.

Tropical fruit flies “are recognized by entomologists as among the most destructive agricultural insect pests in the world,” the authors write. Government agencies have pulled out all the stops to quash the California invasions, trying everything from early-detection programs to limitations on imports from infested areas.

But fruit flies have managed to evade these measures. The researchers gathered detection reports from government agencies and other data sources from 1950 to 2012, then mapped the sightings. Two fruit fly species appeared in the 1950s; by the 1980s, that number had grown to 13. And the number of cities known to harbor the bugs skyrocketed from two to more than 300 in 50 years.

One consolation is that the local fruit fly populations are “extremely small,” the team writes. But for now, eradication remains out of reach. Roberta Kwok | 6 August 2013

Source: Papadopoulos, N.T. R.E. Plant, and J.R. Carey. 2013. From trickle to flood: the large-scale, cryptic invasion of California by tropical fruit flies. Proceedings of the Royal Society B doi: 10.1098/rspb.2013.1466.

Image © Scott Bauer, U.S. Department of Agriculture | Wikimedia Commons