08/13/98 - Sebring Mediterranean Fruit Fly Update - DACS

Provided by Dr. Marion Fuller
Florida Department of Agriculture and Consumer Services (FDACS)

Report Dated 08/13/98

Sebring

Fly count: Another fly was detected Monday, August 10th, bringing the total to 134 flies since the original find on July 9. This fly was picked up in the northern block, in the grove site of the original infestation. The regulated area is unchanged, and currently encompasses 144 square miles. No flies were detected on the yesterday or the day before.

Trapping: As of August 11, there were 4441 traps deployed in a 207 square mile survey area: 3462 Jackson, 265 McPhail, and 714 yellow panel traps.

Treatment:Ground crews continue to treat areas in the buffered areas around sensitive sites. The next aerial bait treatment is scheduled for this Saturday, August 15, weather permitting, and pending EPA approval.

Environmental Monitoring: The following results for malathion in water samples collected August 9 (pre) and August 10th (post) representing the fourth treatment of the northern block and third treatment of the southern block.
Pretreatment Post treatment
Lake Sebring BDL 0.1 - 0.3 ppb (between the MDL and PQL)
Dinner Lake 0.5 ppb 12 ppb
Little Red Water BDL 0.1 - 0.3 ppb (between the MDL and PQL)
Denton BDL 0.65 ppb
Little Bonnet BDL 0.1 - 0.3 ppb (between the MDL and PQL)
Jackson Canal BDL 0.1 - 0.3 ppb (between the MDL and PQL)
Red Beach BDL 0.60 ppb

Malaoxon was not detected in any of the samples.

The method detection limit (MDL) and practical quanitation limit (PQL)for both malathion and malaoxon is unchanged at 0.1 ppb and 0.3 ppb, respectively.

The following results are from drift card samples collected during the same treatment event:

  • Dinner Lake: positive at water's edge (trace); positive at 50 m, 100 m, and 150 meters from water's edge.
  • Red Beach Lake: Positive at waters edge (trace); 50 meters; 100 meters (trace); and 150 meters from waters edge.
  • Little Red Water: All samples positive (trace) at waters edge, 50 m, 100 m, and 150 meters from waters edge.

    The results of samples collect from the product formulation and bait mixture associated with the same treatment event:

    malathion malaoxon isomalathion
    Product formulation 95.2 % BDL 0.17%
    Bait mixture 19.4 %

    These results are consistent with the registered product specifications.

    Health Monitoring: DOH (Department of Health) has received a total of 9 health related calls since the program began. Of these, 1 has been classified as "not a case", 4 have been classified as "unlikely" cases, 3 have been classified as "possible" cases, and the last call is still in follow up. Case classifications are tentative, and can change, when/if additional information is gathered.

    By way of explanation, when a call concerning possible health effects is received by DOH a determination must be made as to nature of the relationship between the reported symptoms and the given pesticide exposure (in this situation, to the malathion bait mixture). To do this, DOH obtains information from the caller at the time information is received, then subsequently, additional information is gathered from the caller (if necessary), their physician (if seen), and FDACS (if certain information is needed to assist in documenting exposure.) Based on all of this (reported symptoms and exposure potential), cases are classified into one of seven categories. The system is designed to include cases of systemic toxicosis (poisonings), local adverse effects (e.g. dermal irritation), as well as responses to odors and exacerbation of pre-existing conditions (e.g. reactive airway responses). Therefore, the surveillance system is designed to include cases of pesticide-related illnesses, or pesticide related responses - not just cases of pesticide "poisonings". In this way, DOH can be sure to capture patterns of responses that have not been documented in the literature, and which may not be previously recognized as an adverse effect associated with a given pesticide exposure. The system is not designed to determine if the reported symptom is due to the active ingredient, a co-product, or a carrier (although, under certain circumstances that may be suggested by the data).

    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

    The UF/IFAS Pest Alert WWW site is at: http://pestalert.ifas.ufl.edu/