It is called "lumsek" in the Cordilleras. In the science world, it has been identified as a species of the genus Hygrophorus.
This local mushroom grows in cold areas covered with pine trees, it was found in a study titled "Survey, Characterization, and Evaluation of ‘Lumsek’ Mushroom’s Effect on Housefly."
In fact, reported researcher Shelly Abag of the Benguet State University (BSU) in the Benguet capital town of La Trinidad, "lumsek" has also been found to have a mycorrhizal relationship with pine tree seedlings. (Mycorrhiza is the symbiotic association of the mycelium or mass of interwoven filamentous hyphae or threads of a fungus with the roots of a seed plant.)
Abag observed that the cap of a "lumsek", which grows from four to 15 centimeters, is white when young and entirely grey-black when dried.
"It has a pleasant smell when newly harvested and slimy when damp," said Abag as reported by Annie Ruth Valiang of the Mountain Collegian, the official student publication of BSU. Currently headed by Dr. Rogelio Colting, BSU is the regional university in the Cordillera.
Abag noted that 10 grams of fresh "lumsek" mushroom was significantly better in killing flies than the fly bait and fly paper of a multinational chemical company.
"It effectively killed 97 percent of flies relative to the fly paper," she said.
Other countries like the United States and Canada also have a mushroom scientifically named Amanita muscaria similar to "lumsek", Abag reported. It is possible that the insecticidal compound found in Amanita may be similar to the compound found in "lumsek".
The researcher concluded: "Whatever may be responsible for this property of this fungus there is nothing to worry about. Basing from experience, this mushroom is not poisonous." – Rudy A. Fernandez