Region: South America > Ecuador
Categorized: Biology, monitoring, surveillance and scouting
Tagged:
The genetic characterization of fall armyworm populations in Ecuador and its implications to migration and pest management in the northern regions of South America
The fall armyworm (Spodoptera frugiperda) is a moth pest native to the Western Hemisphere
that has recently become a global problem, invading Africa, Asia, and Australia. The
species has a broad host range, long-distance migration capability, and a propensity for the
generation of pesticide resistance traits that make it a formidable invasive threat and a difficult
pest to control. While fall armyworm migration has been extensively studied in North
America, where annual migrations of thousands of kilometers are the norm, migration patterns
in South America are less understood. As a first step to address this issue we have
been genetically characterizing fall armyworm populations in Ecuador, a country in the
northern portion of South America that has not been extensively surveyed for this pest.
These studies confirm and extend past findings indicating similarities in the fall armyworm
populations from Ecuador, Trinidad-Tobago, Peru, and Bolivia that suggest substantial
migratory interactions. Specifically, we found that populations throughout Ecuador are
genetically homogeneous, indicating that the Andes mountain range is not a long-term barrier
to fall armyworm migration. Quantification of genetic variation in an intron sequence
describe patterns of similarity between fall armyworm from different locations in South
America with implications for how migration might be occurring. In addition, we unexpectedly
found these observations only apply to one subset of fall armyworm (the C-strain), as
the other group (R-strain) was not present in Ecuador. The results suggest differences in
migration behavior between fall armyworm groups in South America that appear to be
related to differences in host plant preferences.
