Field assessment of female mating success based on the presence-absence of spermatophore: a case study with spruce budworm, Choristoneura ?umi?erana

摘要

The mating success of female sprace budwoims was evaluated using the presenceabsence of spermatophore in genitalia. Sampling was conducted in the 1970s in Atlantic Canada at 21 locations/years characterized by high budworm densities. More than 99.8% of in-flight females (captured at light or malaise traps) and migrant females (collected while ascending above tree canopies or in the airspace) were mated, which may reflect physiological constraints restricting flight in gravid females. About 85% of resident females (collected using sweep nets or by fogging trees with insecticide) were mated; mating success was low among young females collected early in the season and increased over time to reach a level similar (98%) to that of females that died from natural causes. These findings highlight the importance of unbiased estimates of mating success to evaluate the efficacy of mating disraption and the role of mate-encounter Allee effects on population dynamics.