Country: United States

Title: Q-Biotype of the whitefly, Bemisia tabaci

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Plant Protection and Quarantine (PPQ) is applying the current policy for the B-Biotype of the whitefly, Bemisia tabaci (“non-reportable/non-actionable”), to the recently detected Q-Biotype.  PPQ will facilitate the work of the ad hoc Q-Biotype Whitefly Taskforce, with the purpose of identifying the tools and principles necessary to minimize the impact of this high-consequence plant pest on affected industries.

 

The Q-Biotype is now the most prevalent type of whitefly in the Mediterranean basin.  It is resistant to many of the insecticides that are effective against the previously dominant B-Biotype.  The Q-Biotype has greatly complicated insect management in the Mediterranean basin and has been associated with significant increases in insecticide use.

 

In December 2004, specimens of the Q-Biotype whitefly were identified from a retail market in Tucson, Arizona.  This resulted in PPQ convening a New Pest Advisory Group (NPAG) for information gathering and recommendations.  The NPAG has recommended that PPQ apply its current “non-reportable/non-actionable” policy of the B-Biotype of the whitefly, Bemisia tabaci, to the Q-Biotype.  The NPAG’s recommendations were based on the following findings:

 

The B- and Q-Biotypes can not be distinguished morphologically.  The two biotypes can be distinguished using biochemical and/or molecular diagnostic tests but these require extended periods of time, expertise, and specialized facilities.  This in combination with the wide host range renders detection at ports impractical. 

 

Experience with B-Biotype has shown that this species of whitefly is difficult, if not impossible, to either contain or eradicate.  The Q-biotype has enhanced ability to resist the effect of insecticides and thus poses challenges beyond the B-biotype.

 

Therefore, there is low probability that regulatory action against this pest would be effective.

 

Subsequent to the recent discovery of Q-Biotype, industry leaders met with members of the scientific community and Federal and state regulatory officials in April 2005 in Phoenix, Arizona, to explore options for dealing with the Q-Biotype whitefly.  As a result, industry leaders have requested that APHIS-PPQ coordinate the formation of an ad hoc taskforce to address relevant issues pertaining to this pest.

 

The ad hoc Whitefly Taskforce is now being formed under PPQ leadership to facilitate communication and cooperation among relevant representatives from industries (production and protection), the research community, and Federal and state regulatory agencies.  It will provide a flexible framework within which these groups can cooperate in responding to this pest.  Members of the taskforce will work together to effectively address and avoid the potential problems posed by Q-Biotype whitefly; in particular, the economic damage that could potentially affect all industries if this pest were to become established and develop additional resistance to insecticides.

 

Posted Date: June 1, 2005, 9 a.m.