Disappearing Act
UCSB biologists document the secondary extinction of a disease-carrying mosquito following rat eradication on Palmyra Atoll.
The Asian tiger mosquito — carrier of such diseases as dengue, yellow fever, Rift Valley fever, Chikungunya and Zika — appears to have vanished from Palmyra.
Not native to the small atoll 1,000 miles south of Hawaii, Aedes albopict likely came to Palmyra during World War II, when the United States took it over as a base of operations. The military imported many other species as well, including the common black rat, Rattus rattus, a large tree-dwelling rodent whose blood fed many of the mosquitoes. The rats also ate juvenile coconuts, leaving the shells as potential habitat for mosquito larvae.
In 2011, to help Palmyra recover from the ecological damage wreaked by the non-native rats, land managers implemented an aerial drop of rodenticide that quickly eradicated them. Without rats to feed on, the mosquitoes were left with only humans to bite. But rather than being bitten more, people eventually were not bitten at all. Researchers began to wonder if the Asian tiger mosquito had disappeared along with the rats. Now, in the journal Biology Letters, a team of UC Santa Barbara scientists and colleagues at the United States Geological Survey (USGS) chronicles this unique example of co-extinction.
