Abstract: The invention relates to the use of triazolopyrimidines of the formula I In which: R1, R2 are hydrogen, alkyl, haloalkyl, cycloalkyl, halocycloalkyl, alkenyl, alkadienyl, haloalkenyl, cycloalkenyl, halocycloalkenyl, alkynyl, haloalkynyl, C3-C6-cycloalkynyl, phenyl, naphthyl, or a five- to ten-membered saturated, partially unsaturated or aromatic heterocycle which contains one, two, three or four heteroatoms from the group consisting of O, N and S, where R1, R2 may be substituted as defined in the description or R1 and R2 together with the nitrogen atom to which they are attached may form five- to eight-membered heterocyclyl or heteroaryl which is attached via nitrogen and may contain one, two or three further heteroatoms from the group consisting of O, N and S as ring members and/or may be substituted as defined in the description; L independently of one another are halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, alkenyloxy, cyano, C(?O)A1, S(?O)mA2, NRcRd or NRc—(C?O)—Rd, where A1, A2, Rc, Rd and m ar