Male mating behaviour is shaped by previous experience of both conspecific and heterospecific females in the seed bug Lygaeus simulans

Mating decisions are often context-dependent. For example, choosy individuals may benefit from relaxing mate preferences if conspecific mates are scarce. However, prior experience of heterospecifics can also alter mating decisions, and this can influence the strength of species discrimination and/or sexual selection. Here, we investigate the effect of previous mating opportunities on the subsequent mating decisions of male Lygaeus simulans seed bugs, a species known both to experience reproductive interference (reproductive interactions with heterospecifics that are costly) and also male mate choice for larger females. We used a nested, hierarchical design whereby focal males were: (1) paired with a conspecific female or remained unpaired on day 1; (2) paired with a conspecific female, a heterospecific female, or were unpaired on day 6; (3) paired with a conspecific female or a heterospecific female on day 8. The sister species L. equestris provided the heterospecific partners. We found that males were less likely to mate with heterospecific L. equestris females if they had previously encountered a heterospecific, but only if copulation had not occurred during that encounter. Additionally, the willingness of males to copulate with conspecifics increased when males had prior conspecific experience, and decreased with prior heterospecific experience, suggesting that male pre-copulatory mating decisions are plastic and can be influenced by experience of both con- and heterospecifics.