Changes in Male Perseverance in Courtship and Female Readiness To Mate in a Strain of the Parasitic Wasp Nasonia Vitripennis Over a Period of 20+ Years

Abstract

In 1971, a laboratory culture of the parasitic wasp Nasonia vitripennis (later known as Strain Leiden LabII) was initiated for a study of the organisation of insect reproductive behaviour. Reliable, quantified data are available for a period of 20+ years (ca 500 generations). Data on behavioural changes in laboratory cultures seem to be lacking entirely, although the issues at stake may be important. Therefore, we compare data sets from different periods in a search for effects of selection exerted by the culture situation. Shifts in female reactivity to male courtship stimuli (decrease), in processes underlying female sexual receptivity (increase), and in processes underlying male perseverance once engaged in courtship (decrease), are revealed. Results are related to side effects of the key courtship-stimulus (the male's volatile mandibular pheromone) and compared to long-time cultures of Melittobia species. In Melittobia, differential side effects of pheromone release are absent; such changes as revealed in Nasonia could not be found.