Fig. 6. In choice mating experiments, the females of Chorthippus albomarginatus and Ch. oschei mated rather assortatively with intact conspecific males, in 10-20 % of cases they mated with heterospecifics (a). When chemical component of the courtship was eliminated (the females antennae were cutted) (b), or visual component was eliminated (the males tibiae were cutted) (c), the females mated assortatively as well. After the elimination of acoustic component (males wings were cutted), the percentage of matings crucially decreased (d). The behavioural experiments were conducted during two weeks, 8 hours every day, an equal number of the females and males were placed in one cage during the experiment (number of individuals is shown on the left). Place and date of the collected material: Ch. albomarginatus - Germany, Bavaria, Erlangen, 5.07.2002, Ch. oschei - Hungary, prov. Bekes, Battonya, 16.07.2002.