Overwintering fertilized adults and bias sex ratios: New aspects of the life history of Megacopta cribraria (Hemiptera: Plataspidae)

Overwintering male and female Megacopta cribraria were dissected throughout their quiescence to determine the status of their reproductive organs. Results from an overwintering population of females (n=46) collected in March 2013 showed about 48% were storing sperm in their spermatheca. A follow up study was conducted from later September 2013 to March 2014. Groups of approximately 40 overwintering adult males and females were dissected weekly. Results indicated that 14% of females (n=555) were storing sperm, a proportion lower than that observed in spring of 2013. Furthermore all the males (n=486) were found to be storing sperm. This study indicates that both males and females are capable of reproductive quiescence. Additionally the overwintering generation had a male-to-female ratio of 1: 1.84. The biological importance of this reproductive strategy is discussed.