Control of Tadpole Shrimp-03



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Project Leader and Principal Investigators

Brian Tsukimura, Dept. of Biology, CSU Fresno


Scientists working on this project examined the efficacy of copper sulfate (bluestone) and an organic plant compound (methyl farnesoate liposomes) to control tadpole shrimp. This invertebrate pest is of concern because it uproots young rice plants and reduces yield.

In one set of experiments ground applications of bluestone in ring plots were very effective in eliminating tadpole shrimp from rice fields. The application level was equivalent to 15 pounds per acre. These studies were also conducted at relatively warm water temperatures. Future research will test the efficacy of copper sulfate at lower application levels and cooler water temperatures.

Bluestone applications typically occur after adult shrimp have already released hundreds of eggs. Scientists are examining methyl farnesoate (MF), an organic compound derived from both crustaceans and plants, as a possible tool for disrupting the shrimp's reproductive cycle. Protein pellets containing MF-laden liposomes that are attractive to the shrimp as a food source will be the method of application. Unfortunately, research with this compound experienced a setback in the delayed production of the pellets. Efforts continued in the off-season to improve development of the pellets.

Researchers are optimistic that the combination of copper sulfate with an MF-treatment will both reduce the number of tadpole shrimp damaging crops and the number of eggs affecting future plantings.

As farm equipment is the most likely way tadpole shrimp are spread, rinsing of equipment after use in an infected field is strongly recommended.


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