Drosophila suzukii is an economically important pest of fruit in America and Europe as well as in Asia. Sparassol (1) and methyl orsellinate (2) are produced by Sparassis cripta and S. latifolia during culture. Fumigant and contact toxicities of synthetic sparassol (1) methyl orsellinate (2) and methyl 2,4-dimethoxy-6-methylbenzoate (DMB; 3) were investigated. The possible mode of action of the compounds was pursued by assessing their inhibition activities against acetylcholinesterase (AChE) and glutathione S-transferase (GST). Little or no fumigant activity was observed from tested compounds. In contact toxicity activity, LD50 (μg/fly) values are 5.29, 1.18, 0.02 for male, and 11.14, 2.27, 0.05 for female, respectively. In enzyme inhibition assay, DMB (3) which easily synthesized from sparassol could be an alternative agent for controlling insect pest. In addition, Sparassis species could be an industrial resource of sparassol.