Effects of density experience on mate guarding behavior by adult male Kanzawa spider mites

In the Kanzawa spider mite, Tetranychus kanzawai (Acari: Tetranychidae), adult males guard pre-reproductive quiescent females. I experimentally examined the effects of density experience during development and/or after adult emergence on precopulatory mate guarding behavior by T. kanzawai males. Mate guarding behavior was modified by density experience after adult emergence. When males had previously experienced high density after adult emergence (n = 71), 73.2% of them engaged in precopulatory mate guarding. In contrast, when males had previously experienced low density after adult emergence (n = 82), 61.0% of them did not guard females. Mate guarding with physical contact occurred more frequently when males had previously experienced a high density of potential rivals than when they had not, but the difference in behavior between the two groups of males was marginally not significant. Nevertheless, these results suggest overall that T. kanzawai males change mate guarding behavior in response to previously experienced density.