Sterile Insect Release Facility1833 57th Street

Sarasota, Florida

Florida Department ofAgriculture

and Consumer Services

Approximately 100 million pupaeare imported each week for rearingand release into one of three high-risk Preventive Release Blocks:Tampa, Miami and Sarasota/Bradenton. Irradiated pupae are shipped fivedays a week from the USDARearing Facility in Guatemala.Flies are fed food and water usingan agar/sugar-based gelatin that isplaced on each tower tray. Eachtower holds about 1.67 millionpupae. The flies are held for 4-6days, which allows them to reachsexual maturity prior to release.

The Sarasota SIRF is the first SIToperation to make full use of thenew Eclosion Towers developed bythe Mexican Fruit Fly Facility andMethods Development in Mission,Texas. Each tower consists of 60-70 trays stacked vertically, witheach tray holding approximately25,000 flies. Nearly five towersare used per flight. That’s almost70 lbs. worth of flies, more than5.25 million dropped every flight.

Pupae Preparation and Eclosion

Loading and Feeding of Fly Pupae

New Eclosion Towers

Towers with mature flies (4-6days old) are moved into pre-chilled cold rooms and are heldat 38 degrees for 15-20 minutes.The cold renders the fliesimmobile for collection. Pupalcases and unemerged flies arevacuumed from every screenprior to fly collection.

Tower screens are dumped insideof hoppers to collect the flies intothe release box. Approximately70-80 lbs. of flies are collected foreach flight. Once full, the releasebox is weighed and then rushedto the aircraft for placement ontothe refrigerated release machine.Flights are set up to ensure that allflies are released within a four-hour period following the start ofchilling.

Fly Knockdown (Preparing for Flight)

Methods Development and Quality Control

Assessing the quality of the sterileflies is a critical component of asuccessful SIT program. QualityControl technicians check everyshipment using a variety ofinternationally accepted tests,and compare the results to datafrom the Moscamed RearingFac i l i ty in Guatemala, fromwhich the flies originate.

Three primary tests are used todetermine the quality of the flies:emergence, flight ability andsexing. Each lot of flies receivedis randomly sampled and tested.The flies used in Florida since 1998have been genetically engineered tofavor the production of onlymale flies (app. 99.8% male). Thesterilized male is the activeingredient in SIT, because theywill mate with the wild females,which will then produce no offspring.

Aerial Release Operations

The release planes used are twin-engine turbine class aircraft, witha two-person crew (pilot and flydisperser). Most of the flies arereleased at an altitude of 2000 feetabove the ground. In some caseswe modify our altitude as directedby Federal Air Traffic Controllersin release areas close to the majorairports in Tampa and Miami. Theaircraft fly an average of 10-12flights per week (35 hours/week).

The release box is mounted insidethe cargo area of the plane. Thereis an air conditioning compressormounted in front of the box tokeep the temperature around 38degrees Fahrenheit which keepsthe flies immobile during flightand release. Chilled flies are releasedthrough the bottom of the aircraftat a rate of at least 125,000 flies/sq. mile or PRP. (Release rate isincreased to 400,000 flies/sq. mileduring eradication programs.)

Aerial Mapping / GIS Data

All SIT aircraft use Global Information System/GIS-generated datato record a variety of information about each flight as it occurs. This datacan be reviewed and overlaid onto mapping software to chart exactlywhere the plane flew and details about the fly release.

This map shows the paths of two flights flown in one week over Miami-DadeCounty. A solid line indicates when the release machine is dropping flies,and the dotted lines indicate the flight path when the machine is off.

Pest Detection and Survey

State and federal trappers inspect more than56,000 fruit fly traps every year statewide. Thisis more than a threefold increase from trap levelsin 1997/1998, when Florida last eradicated theMedfly in programs which spanned nine countiesand cost roughly $32 million. Statewide, timelytrapping is the cornerstone of a program designedto keep out harmful pests before they everbecome established.

Other improvements in our cooperativetrapping program include: better, more attractivefly baits; continuing, specialized training fort rappers ; and increased au tomat ion ofrecordkeeping using GIS software. Trappingp r o t o c o l s a n d p r o c e d u r e s a r e t h e s a m es t a t e w i d e , which lends credibility and ac-countability to the detection program.

Fruit Fly Identification Laboratory(FFIL) / Blacklight ID

The FFIL verifies sterility of allMedflies captured in some 56,000monitoring traps statewide. Aftersterile Medflies are released over aPRP area, many thousands wind upin detection traps each week. Annu-ally, between one and three millionf l ies are submit ted on 200,000-350,000 fruit fly traps to the FFIL.All mass-reared Medflies used inSIT are marked with a flourescentdye during irradiation, which makesthem easy to spot under blacklight.

Any f l i es found wi thoutflourescent markings are dissectedfor other evidence of sterility.

The FFIL also collects informationon sterile Medfly recaptures, allowingthe program to examine its aerialrelease and ground monitoring andadjust as necessary to ensure optimumsterile fly coverage in release areas.

History of the Sterile Insect Technique and MediterraneanFruit Fly Preventive Release Program in Florida

David DeanSupervisor, Fruit Fly Identification Laboratory, Palmetto

Florida has been much involved in the development and success of the Sterile Insect Technique(SIT) as conceived by E. F. Knipling in 1937 (USDA Bureau of Entomology) and further developedby E. F. Knipling and A. W. Lindquist. The earliest field performance tests of SIT were conductedagainst the primary screwworm fly, Cochliomyia hominivorax, on Sanibel Island, Florida in 1951-1953. Success of this test and a subsequent small-island test for the eradication of the screwworm inCuracao (170 square miles) ultimately led to the establishment of mass rearing facilities in the AvonPark - Sebring area of Florida in 1957. By 1959 the first area-wide eradication of an insect pest wascompleted with the elimination of the primary screwworm fly from Florida. The support of FloridaGovernor Collins and Florida livestock producers was critical to the success of the program. Sincethat historic event, SIT has been used successfully to eradicate the screwworm fly from the UnitedStates, Mexico and Central America to the isthmus of Panama and has proven to be a successfularea-wide method of control for many insect pests, including the tsetse fly, fruit flies and moths.

SIT is a biologically-based birth control method which has been called an autocidal pest controlprogram. It requires the ability to mass rear large quantities of the specific pest targeted foreradication and a sustained field release of sterile males in numbers great enough to outnumber thepotential for mating by wild males. Wild female insects mated with sterile males do not produceoffspring. Irradiation with a specific level of gamma radiation results in sterilization of every SITmale. This low level of irradiation causes dominant lethal mutation by altering the chromosomes inthe rapidly dividing reproductive cells in the ovaries and testes and has little or no effect on thenormal somatic cells found in the remaining body tissue. Thus, the term ‘sterile insect’ refers to onewhich has lost its reproductive capacity through irradiation without greatly altering its longevity andvigor.

The advantages of SIT over conventional insect control methods are major and numerous. First, itis safe for the public and has no adverse impact on the environment. Second, it is biologically basedand is specific only to the species targeted for control, unlike most non-selective chemicalapplications which cause broad indiscriminate mortality of many species of organisms. Third, itincreases in efficiency as the target population decreases in size, whereas chemical control decreasesin efficiency as the target population decreases; unlike chemicals, sterile males have the ability to seekout the remaining wild females over a wide area.

The application of SIT has proven to be a cost-effective solution to area-wide pest control,suppression and eradication. Another successful application strategy is prevention. In areas wherethere is a high risk of pest invasions that can threaten food security and supply or even public health,the avoidance of the establishment of pest species is critical. Since the last eradication ofMediterranean fruit flies (Medflies) in Florida, which was declared in October 1998, sterile Medflieshave been released on a preventive basis in areas historically shown to be at high risk for newintroductions. This Preventive Release Program (PRP) is a proactive approach to the heightenedthreat of new Medfly introductions due in part to increased international trade and travel and thecurrent high growth rate in urban areas of Florida.

The current preventive sterile Medfly release program (PRP) in Florida accomplishes the following:

PRP establishes a preemptive presence of sterile Medflies in high-risk areas so that they can functionwith maximum efficiency, while the initial introduced pest population remains small before it canbuild in numbers.

PRP maintains an operational SIT infrastructure in place to combat any new Medfly introductionsthroughout the state by immediately redirecting the existing sterile fly releases to new target areas.

PRP helps assure environmental and public safety during eradication efforts, since all potentiallyhigh-risk Medfly introduction areas in Florida are located in densely populated urban areas.

PRP is cost-effective, since it is ultimately less expensive to take preventive measures through earlydetection and eradication of new introductions while they remain in small isolated areas than toconduct large eradication and control measures over extended areas and for longer duration.

Fruit Fly Identification Laboratory, Palmetto FL

A major role of the Fruit Fly Identification Laboratory (FFIL) is to verify sterility of allMediterranean fruit flies captured in fruit fly monitoring traps within the state. Annually, betweenone and three million sterile Medflies are submitted on 200,000 to 350,000 fruit fly traps to the FFILin Palmetto. All mass-reared Medflies used in sterile release programs are marked with a fluorescentdye at the time of irradiation, to facilitate rapid recognition of sterile release flies and wild flies.

A complicating factor for any Preventive Release Program (PRP) is that sterile Medflies areequally attracted to fruit fly detection traps, which are used to detect or monitor the presence of wildMedflies. Therefore, it is necessary to verify that all Medflies captured in detection traps are indeedsterile. Any Medflies which are found without adequate fluorescent marking are dissected forevidence of irradiation damage to verify their sterility. If a suspect fly is diagnosed as a wild Medfly,maturity and evidence of mating can also be determined by dissection and microscopy. In addition,DNA from a fly specimen is often used to help establish information as to the geographic origin of anintroduced wild Medfly.

The FFIL also collects information on sterile Medfly recaptures within preventive release areas.This recapture data is used to monitor the performance of the Preventive Release Program. Thedensity and distribution of sterile Medflies within preventive release areas are routinely mapped andanalyzed using Geographic Information Systems (GIS) analysis, as a part of the quality assurance andmanagement of the program. Aerial release and ground monitoring can be examined and adjusted toensure optimum sterile fly coverage in release areas or the desired ratio of sterile flies to wild flies, inthe event of an emergency eradication program.

Sterile Insect Technique (SIT) Staff(1) Federal Project Leader (Statewide SIT Director) - Proposed Vacancy(1) Supervisory PPQ Officer(2) PPQ Officers(1) Admin Support Assistant(1) Senior Biological Science Technician (Methods Development)(2) Biological Science Technicians (Quality Control and MD)(1) Maintenance Worker(16) Insect Production Workers

Citrus Canker Staff - Sentinel Survey(1) Supervisory PPQ Officer(1) PPQ Officer(1) Data Entry Clerk/Secretary(6) PPQ Domestic Technicians

Exotic Pest Survey Staff - New Domestic Survey Initiative(1) Supervisory PPQ Officer(1) PPQ Officer

SARASOTA STERILE INSECT RELEASE FACILITY

Staffing and Operations

MAJOR SIT EXPENSES

Overall Federal Allocation for FY 2002 - $2.4 million (supports eightmonths of operations)

Required Federal Allocation - $3.4 million for full year of operations

Staffing - 24 staff years - approximately $900,000

Services - Aerial Release Contract - $465 per flight hour - 35 hours/week = $846,000

Supplies - Sterile Pupae - $275/million pupae @ 100 million pupae/week = $1,430,000

Rent/Utilities - Rent @ $174,000 per year; Utilities @ $3,000/month= $210,0000

SARASOTA STERILE INSECT RELEASE FACILITY

Budget and Expenses