Nuclear genetic diversity and structure of Anastrepha ludens wild populations evidenced by microsatellite markers

The Mexican fruit fly, Anastrepha ludens is an important pest that causes
widespread damage to a number of fruit crops in Mexico. The Sterile Insect
Technique (SIT) is commonly used for its control. However, the existence
of natural barriers can give rise to a population structure in neutral
loci and possibly behavioral or adaptive traits that interfere with SIT.
For this reason, it is important to understand the genetic diversity and
structure of A. ludens populations and to better understand the
evolutionary ecology and population processes in view of possible
expansions and possible host shifts due to climate change. We genotyped
nine nuclear DNA (nDNA) microsatellite loci among fruit fly populations
collected from five biogeographic areas within Mexico, Mexican Plateau,
the Northeastern Coastal Plain, the Pacific Coast, the Gulf Coast of
Mexico, the Soconusco and a laboratory strain. The nuclear genetic
diversity was moderate (from He = 0.34 to He = 0.39) within the wild
mexfly population. We found that populations were clustered in three
genetic groups (K=3). The diversity and genetic structure of A. ludens are
produced by environmental and geological conditions as well as local
conditions like anthropogenic perturbation which would produce population
expansion and the existence of possible predators that would affect the
population density. Gene flow showed recent migration among populations.
The laboratory strain showed less diversity than the wild samples. Large
values of current and ancestral population size suggest high resistance to
climatic changes, probably due to biological attributes, such as its
polyphagous, multivoltine and high dispersal characteristics. In
particular ecosystem fragmentation and perturbation as well as the
existence of new plant hosts all of which would probably increase the
abundance of flies.