Progress 10/01/03 to 09/30/06
Outputs
Coqui frogs are a nuisance in Hawaii emitting loud shrieks keeping residents awake at night. They threaten the potted plant industry because they often hide away in plants and recipient importers threaten banning Hawaii plants. Coqui frogs appear to be depleting the ecosystem of insect prey and therefore could alter the ecology of Hawaii. Initial work was with caffeine and pyrethrin which were identified by others as potential pesticides. The toxicities of caffeine and pyrethrin were tested in the laboratory and in the field. Their effects were found to be additive and not synergistic. It was also observed that concentrated populations of coqui frogs in Hawaii that were reported in the gray literature could not be confirmed. Populations were relatively low. Effective concentrations of caffeine were at levels that would be toxic to mammals. For this reason it was concluded that caffeine and pyrethrin should not be pursued as remedies for the coqui frog. The project
moved forward to warm water disinfestation which will be reported under another number.
Impacts
Work on caffeine and pyrethrin was terminated. Work was begun on warm water disinfestations.
Publications
- No publications reported this period
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Progress 10/01/04 to 09/30/05
Outputs
Coqui frogs are a nuisance in Hawaii emitting loud shrieks keeping residents awake at night. Also, they threaten the potted plant industry because they often hide away in plants and recipient importers threaten banning Hawaii plants. Initial work was with caffeine and pyrethrin. This proved not to be a desirable treatment. Current work is with hot water disinfectation of potted plants going out for sale. With the help of Charles Nelson, hot water units were constructed. They all have propane burner heaters and are designed to re-use hot water. The prototype was sent to Hilo for trials by Arnold Hara. A large unit was built for a farm on Oahu. This unit will be used by all the farmers who care to use it. Plans were prepared for the State of Hawaii Department of Agriculture. They will build units for stakeholders around the state.
Impacts
Threats to ban import of Hawaii potted plants will disappear because plants will be hot water treated.
Publications
- No publications reported this period
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Progress 10/01/03 to 09/30/04
Outputs
Simulated field trials in the laboratory were conducted using a 1% caffeine/0.01% pyrethrin cocktail on coqui frog. When hidden in moss such as in the day, the pesticide was ineffective even though it was lethal when frogs were in bare aquaria devoid of cover. Field trials were initiated. They were conducted at night when frogs emerge from cover to feed and breed. Counting was explored and statistically reproducible values were obtained before and after spraying were counted as a grid. The counting was very labor intensive and relied on prior training of the counter. The counting may not be as accurate as toe clipping methods discovered in the literature after the current studies were started but would probably draw less attention than methods relying on cutting off frog toes without anesthetic. Other methods of validation were tried but preliminary data suggest that spraying must be done at night and that an 80% kill rate may be expected.
Impacts
More effective methods for determining pesticide efficacy have been developed. They require less time and manpower than existing methods.
Publications
- No publications reported this period
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