Japanese beetles and gypsy moths were accidentally introduced into North America. The most probable reasons these insects have become serious pests in North America is that they
a
became extinct in the late 1980s.
b
have few natural enemies and can outcompete native species.
c
were created in labs by scientists and are resistant to pesticides.
d
are protected by Federal laws.
correct answer: b
have few natural enemies and can outcompete native species.