Masking of the American Cockroach Sex Attractant1

Abstract
Crude extracts prepared from sexually mature virgin female American cockroaches Periplaneta americana (L.), with 5 organic solvents failed to evoke a sexual response in males. Silicic acid chromatography of the inactive acetone extract gave 4 elution fractions, one of which was highly attractive to males; corresponding fractionation of the other extracts did not yield active material. Separate admixture of the active, fraction with proportionate amounts of each of the 3 or of any 2 inactive fractions failed to show a masking effect, but the activity was masked completely by admixture with the combined inactive fractions.