Catching flies with Amanita muscaria: traditional recipes from Slovenia and their efficacy in the extraction of ibotenic acid

Fly control is necessary for maintaining good hygiene on farms. Because organic farmers are skeptical about chemical pesticides, alternative fly control remedies are being considered. Amanita muscaria is a widespread fungus that contains ibotenic acid and muscimol. This fungus has been used to catch flies for centuries, but traditional recipes are poorly described, documented and characterized.The aim of the present study was to collect the traditional methods for preparing A. muscaria for catching flies in Karst and Gorjanci and to investigate the influence of different traditional methods on the release of ibotenic acid and muscimol from the fungal material.The research was conducted in villages in Karst and in the foothills of Gorjanci, Slovenia. Data regarding the traditional recipes of A. muscaria for catching flies were collected through structured interviews with 31 people in Karst and 28 in Gorjanci. Eight preparations were prepared based on traditional methods, and the amount of ibotenic acid and muscimol released from the fungal material at five different time points (0.5, 1, 2, 3 and 24h) was determined by high-performance liquid chromatography (HPLC).Detailed descriptions of preparations used for catching flies were obtained from three informants in Karst, who were originally from other parts of Slovenia, and 13 informants in the foothills of Gorjanci. However, there were no reports regarding current usage. A total of 9 different methods were collected. Some methods were simple and included soaking in milk or water or dripping a little milk onto the mushroom. Others were more complex and included a combination of heat or mechanical processing and soaking in milk or water. For all preparations, the release of ibotenic acid was time-dependent, with the extracted amount increasing over time. Although milk was used more often than water in the traditional recipes, the release of both substances was not dependent on the solvent used. Fungal material that was exclusively soaked in water or milk released the smallest amount of ibotenic acid and muscimol at each time point. Additional heat and mechanical processing led to faster release of ibotenic acid and muscimol from the fungal material.The tradition of using A. muscaria for catching flies was present in Gorjanci but not in Karst. The methods used to prepare the fungal material vary, and these differences are reflected in the release profile of ibotenic acid.