CONSPECIFIC INTERACTIONS IN THE LYCOSID-SPIDER RABIDOSA-RABIDA - THE ROLES OF DIFFERENT SENSES

The behavior of sighted and of blind male and female Rabidosa rabida p aired in various combinations was Videotaped and analyzed. When walkin g, neither sighted nor blind spiders could detect motionless conspecif ics prior to contact. When motionless, blind males detected moving fem ales at greater distances than they detected moving males. However, ne ither sighted nor blind motionless males detected very slowly moving f emales at any distance. These data suggested for R. rabida: (1) the ef fectiveness of visually and vibrationally cryptic locomotion, (2) a la ck of form vision, and (3) absence of a close-range, air-borne pheromo ne. In both sexes, visual detection of moving conspecifics by motionle ss spiders provided for accurate orientation responses at greater dist ances than did mechanoreception. Nonetheless, blind females could orie nt accurately toward courting males at close range based on vibrations . Blind males showed courtship display when briefly contacted by anoth er male, suggesting an inadequate chemically based sex-recognition mec hanism. Sighted males showed courtship display after visually detectin g a walking male, but did not do so in response to a courting male, i. e., mutual courtship did not occur. Blind males sometimes did perform mutual courtship, suggesting an inadequate vibratory recognition mecha nism. Unlike salticids, these lycosids did not require vision to initi ate either agonistic display or ritualized fighting.