Two of the more devastating silverleaf whitefly biotypes are the B and Q biotypes. The B type has been in the United States since its discovery in 1985, and the Q type is still a grower concern in 25 states.
Both types of whiteflies can reduce the yield of a broad range of agricultural, fiber, vegetable and ornamental crops. The aggressive B biotype arrived in the U.S. from its native Middle East and Asia Minor range, and it threatened agricultural production throughout the southern United States until new integrated pest management strategies brought it into check.
The Q type brings new challenges. The biotype was first detected in the U.S. in December 2004 on poinsettias from an Arizona retail outlet. Compared to the B biotype, Q is less susceptible to many pesticide types, which means there are fewer chemical options for its control.
There is also concern that resistance to insecticidal controls may occur more rapidly in the Q biotype. So, a Q biotype task force was set up to develop new control recommendations.
Some of the recommendations developed are helping to slow or prevent the movement of the Q biotype into commercial vegetable fields. For now, rapid implementation of the new control strategies has greatly reduced control problems.
For more information about the task force and its findings, click here.