The two pieces of evidence from the text that best support the inference that honeybees—not bumblebees—are responsible for infecting the studied flowers are:
- All the infected flowers researchers picked and tested were close to apiaries.
- All of the bumblebees infected with deformed wing virus were close to apiaries.
These points suggest a correlation between the presence of honeybee apiaries and the infections found in both bumblebees and flowers, indicating that honeybees may be the source of the viruses.