Visual Stimuli Eliciting Mate Refusal Posture in the Mated Female of the Cabbage White Butterfly, Pieris rapae crucivora (Lepidoptera: Pieridae)

Abstract

Visual key stimuli eliciting mate refusal posture (MRP) in the mated female of the cabbage white butterfly, Pieris rapae crucivora, were experimentally analysed. Whiteness or luminosity is an essential feature of the visual stimuli and the critical luminosity at which 50% of the experimental females respond falls between N7 and N10 in terms of the Munsell Number. Females responded almost equally (75%) to the models of different sizes ranging from half to quadruple of the normal size and much less (50%) to the models of one fourth. Females responded almost equally to the differently shaped models including butterfly wing shape, rectangle, square, triangle and disk. Movements, or increase and decrease of the stimulative area was found to be another essential feature. The highest percentage of the response was obtained when the models were presented at the revolution rate of 6/s, which is nearly equal to the wing beat frequency of this male butterfly. Low and high critical revolution rates at which 50% of the experimental females responded are ca. 4 and 20-25 per s, respectively. MRP and its key stimuli were discussed in terms of behavioral ecology. © 1994, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.