Provided by Dr. Marion Fuller
Florida Department of Agriculture and Consumer Services (FDACS)
Report Dated 05/20/98
The Medfly Science Advisory Panel is a six member group of Mediterranean fruit fly experts from Hawaii, Texas, California, and Florida who are considered among the most knowledgeable individuals concerning Medfly biology, trapping, treatment modalities etc. They were originally called together to address the Umatilla infestation, but also took on the Bradenton situation while they were here as a group. The purpose of the meeting was to provide recommendations to the Florida Department of Agriculture and Consumer Services (FLDACS) and USDA concerning the ongoing detection and eradication programs.
USDA and FDACS/Division of Plant Industry briefed the Panel Monday. This included how many flies have detected, trapping procedures (location, density, trap types, etc), fly find locations, larvae find locations, pre-detection trapping procedures, eradication efforts underway, etc.
On the second day the Panel met by themselves to discuss the situation and hash out recommendations.
The following recommendations have been offered to the Department. The Panel is aware of the cost implications associated with their recommendations, but felt their recommendations should be based on best science. Therefore, they did not consider economic factors into the recommendations.
1. The first recommendation (and presented as the most important) deals with changes in detection trapping. It was felt that in light of the Umatilla infestation, that "high risk" areas for Florida should be redefined. The Panel supported the historical view of urban areas around international ports, as appropriate up until this point. Now however, they recommend that along with these (trapping protocols should not decrease in those areas), additional criteria for "high risk" should be considered for areas that have traditionally been considered lower risk.
These criteria might include host availability, human population densities, history of outbreaks, etc. Statewide trapping should be beefed up accordingly, and they recommend:
2. For Umatilla, the Panel recommends continued aerial treatments for another life cycle (for a total of at least eight applications), followed by a life cycle of trapping, then release of sterile flies for three life cycles. Fly density is recommended at 500,000 per square mile.
[The thought process here is based on the need for adequate population suppression - the infestation, though relatively small in area, had a very significant fly density. The panel does not believe that in an infestation of this nature, sterile Medflies will be able to effect eradication without continued chemical treatment over a second generation. They pointed out that sterile Medflies aren't as popular with the wild females as are the wild males - and it is critical to ensure that newly emerging flies are killed before they have an opportunity to breed. Apparently the first thing a newly emerging fly seeks is food, hence the recommendation for the additional treatments. Sterile Medfly release is recommended after the chemical treatment because treatment in buffered areas and other sensitive sites is less effective (incomplete coverage) than aerial application.]
NOTE: The release of sterile Medflies after the eight treatments would not impact the timing for the lifting of the quarantine. That would only be affected (potentially - there are few hard and fast rules!) if additional flies are trapped during or after the latter part of the chemical treatment.
3. For Bradenton the Panel recommends a treatment/trapping program to establish objective evaluation of the ground bait treatments, followed by sterile fly release if the traps indicate a declining adult population. They recommend that the program place 100 yellow panel traps/ square mile to better gauge Medfly density and determine efficacy of treatment.
These are recommendations only - and both FDACS/USDA will consider them very carefully, looking at what can be implemented, and seek clarification on any details that come up as they attempt to move forward. The first recommendation has extreme logistical and cost considerations. (California's annual trapping cost is nearly $8 million, and covers only 1200 square miles.) The Panel acknowledged the very significant differences between the two states, and the difficulty facing Florida regarding all aspects of the program - exclusion, detection trapping, number and location of international ports, etc. but stressed the need at this time to get the resources necessary to trap as recommended. They stressed that Florida must be able to detect emerging populations quickly, prevent their dissemination, and that this can be done most effectively and efficiently through a stronger detection trapping program.
Lastly, the Panel was approached with a proposal for a wide area sterile Medfly release project in the corridor west of I-75 in Hillsborough, Manatee and Sarasota counties. (As previously reported, there have been several calls for such a program following the detections in Bradenton). They recognize the desirability of such, but felt that anything that relates directly to eradication or implementation of an enhanced detection trapping program should be given higher priority.
FDACS - Division of Plant Industy:
Mediterranean fruit fly information
USDA APHIS: Mediterranean fruit fly information
UF/IFAS Fact Sheet ENY-809:
The Mediterranean Fruit Fly
UF/IFAS Fact Sheet ENY-626:
Mediterranean Fruit Fly: What Floridians Need To Know