Evarcha culicivora is a salticid with an unusual preferred diet (vertebrate blood obtained indirectly by preying on female mosquitoes that have themselves had recent blood meals) and an unusual affinity for particular plant species (Lantana camara and Ricinus communis). This thesis is a study of how individuals of this species interact with each other, with a general objective being to clarify the role of visual attention and crossmodality priming in the mate-choice behaviour of this species. E. culicivora’s courtship and display behaviour was shown to be especially complex and highly variable. Experiments on vision-based mate-choice showed that mutual mate-choice behaviour is pronounced in E. culicivora and that both sexes prefer large mates over small mates. Olfactometer experiments showed that E. culicivora is attracted to the odours of bloodfed female mosquitoes, Lantana camara and Ricinus communis and opposite-sex conspecifics. A prior diet of blood-fed female mosquitoes enhances attractiveness to the opposite sex. Opposite-sex conspecifics paired with the odour of blood-fed female mosquitoes are also more attractive. Cross-modality priming effects were investigated in other experiments that showed individuals of E. culicivora responded more to visual cues of opposite-sex conspecifics when in the presence of certain odours (of opposite-sex conspecifics, blood-fed female mosquitoes and L. camara).

Evarcha culicivora is a salticid with an unusual preferred diet (vertebrate blood obtained indirectly by preying on female mosquitoes that have themselves had recent blood meals) and an unusual affinity for particular plant species (Lantana camara and Ricinus communis). This thesis is a study of how individuals of this species interact with each other, with a general objective being to clarify the role of visual attention and crossmodality priming in the mate-choice behaviour of this species. E. culicivora’s courtship and display behaviour was shown to be especially complex and highly variable. Experiments on vision-based mate-choice showed that mutual mate-choice behaviour is pronounced in E. culicivora and that both sexes prefer large mates over small mates. Olfactometer experiments showed that E. culicivora is attracted to the odours of bloodfed female mosquitoes, Lantana camara and Ricinus communis and opposite-sex conspecifics. A prior diet of blood-fed female mosquitoes enhances attractiveness to the opposite sex. Opposite-sex conspecifics paired with the odour of blood-fed female mosquitoes are also more attractive. Cross-modality priming effects were investigated in other experiments that showed individuals of E. culicivora responded more to visual cues of opposite-sex conspecifics when in the presence of certain odours (of opposite-sex conspecifics, blood-fed female mosquitoes and L. camara).

Evarcha culicivora, a species of jumping spider (Araneae: Salticidae from the Lake Victoria region of East Africa, has unusual prey-choice behaviour. It preferred prey is blood-carrying mosquitoes. It also has unusually complex mate-choice behaviour, with mutual mate choice being pronounced. This thesis is a study of E. culicivora’s prey-choice behaviour and mate-choice behaviour, as well as a study of processes underlying selective attention in this unusual species. E. culicivora uses olfaction in unique and often surprising ways. This includes identifying potential mates by odour alone, as well as choosing the odour of potential mates that have recently fed on blood-carrying mosquitoes. The odour of potential mates also primes both sexes for escalating conflict with potential rivals, as well as priming selective attention to the masked odour of specifically potential mates. Besides all this, the odour of blood-carrying mosquitoes primes E. culicivora to selectively attend to the masked odour of specifically this prey. Moreover, the appearance of blood-carrying mosquitoes and of potential mates primes E. culicivora to selectively attend to specifically the appearance of cryptic blood-carrying mosquitoes and cryptic potential mates, respectively. Vision and olfaction can even work together, with olfactory and visual cues from blood-carrying mosquitoes priming E. culicivora to selectively attend to the appearance and odour, respectively, of blood-carrying mosquitoes. Furthermore, E. culicivora has a poorly-understood relationship with two plant species, Lantana camara and Ricinus communis, and E. culicivora can identify these two plant species by odour alone. These plants may be relevant to this salticid as a nectar source by which it supplements its insect diet, but these plants may also be as sites at which E. culicivora males and females find potential mates, with E. culicivora’s interactions on these plants being especially exaggerated and complex.