Daily rhythmicity in the sexual behaviour of Monema flavescens (Lepidoptera: Limacodidae)
European Journal of Entomology
In this study, daily rhythmicity and the effects of age on both calling behaviour were investigated in M. fl avescens. These studies could be helpful in improving our understanding of chemical communication in the reproductive behaviour of Chinese populations of M. fl avescens and of how to use pheromones to detect, monitor and mass-capture this pest in the fi eld. MATERIALS AND METHODS Insects Cocoons were collected from pear and apple trees in Luanxian County, Hebei Province, in late April
... 4 and 2015. The cocoons were kept at 25 ± 2°C, 75 ± 5% relative humidity (RH) and under a natural photoperiod until adult emergence. The adults of M. fl avescens started to emerge at the end of May. After emergence, the male and female moths were immediately segregated into different cages (40 × 40 × 60 cm; 15 moths per cage) containing 10% (wt/vol) sugar solution in different rooms. One room was used for observing calling and copulation and the other for wind tunnel experiments under a 14L : 10D natural photoperiod Abstract. Daily rhythmicity in the sexual behaviour of Monema fl avescens Walker (Lepidoptera: Limacodidae) was studied under laboratory conditions. There was a distinct diel periodicity in female calling, male responsiveness and mating behaviour of M. fl avescens. As females aged there was an advance in the onset and more time spent calling. One day old females started calling 4 h after the onset of the scotophase, and 5 to 6 day old females called during the fi rst hour of the scotophase. About 34.5% of females called on the night they emerged (1 day old) and the peak in calling of 97.8% was recorded for 2 day old females, after which the incidence of calling decreased rapidly with advancing age. Wind tunnel and copulation tests showed that males were sexually mature on the third night and female moths on the second night. The highest value for the percentage mating was recorded for 3 day old virgin females 4 to 6 h after the onset of the scotophase. In fi eld tests, traps baited with 2 day and 3 day old virgin females captured more males than any other trap and most males were captured 4 to 6 h (1 to 2 day old), 3 to 5 h (3 to 4 day old) and 2 to 4 h (5 to 6 day old) after the onset of the scotophase. These results indicate that there is a daily rhythm in the reproductive behaviour of M. fl avescens and provides a better understanding of its sexual behaviour.