VISUAL CUES IN MATE RECOGNITION IN THE DAMSELFLY ISCHNURA ELEGANS VANDER LINDEN (ZYGOPTERA: COENAGRIONIDAE)

Abstract

This paper is dedicated to Philip S. Corbet on the occasion of his 70th birthday.

Abstract

Of the three recognised female morphs of I. elegans, only two occurred in Jagotin, Kiev Province, Ukraine. Andromorphs and infuscans together constituted 99.8% of females in the population, and only 0.2 % were infuscans-obsoleta. The present paper is an experimental study testing male responses to female and male models. Three questions were asked: (1) Is the colour of the model an important cue in mate recognition by males? (2) What is the area of male field of view, responsible for mate recognition? (3) Which is the preferred direction, from which each model elicits the maximal rate of copulatory responses? All colour forms of females regularly occurred in copula with males throughout the day. The violacea and andromorph female models were preferred by males. However, the manner of model presentation strongly influenced male response: copulatory responses were rare when models were presented above the male. Copulatory behaviour with a male model resulted in nearly 70% of cases when the approach was from behind, which was significantly more frequent than with female models. Among female models, the andromorph and grey-green females of the form infuscans were recognised as a female more frequently from behind than the violacea and brown females of infuscans. The role of different visual cues in mate recognition is discussed.

Key words:

• Female colour forms
• Odonata
• Ischnura elegans
• visual cues
• sex recognition