Trade-offs between flight and fecundity in the soybean aphid (Hemiptera: Aphididae).

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is native to eastern Asia and was accidentally introduced into North America in 2000. Within a few years, it was found throughout the U.S. and Canadian soybean-growing regions. The spread of A. glycines in North America is partly ascribed to its great flight capacity. We conducted direct measurements of flight performance of winged A. glycines adults and correlated this to their subsequent longevity and fecundity to determine whether there are trade-offs between flight and fecundity. We also estimated fecundity and development time of the offspring of females that had flown varying distances to examine potential maternal effects linked to flight. The experiment was conducted using a specifically designed aphid flight mill system in which winged aphids were tethered by their abdomens and flight duration, distance and speed were quantified. Fecundity, longevity and reproductive periods of 12-h-old A. glycines alates that had engaged in > 0.5 km long flights were significantly lower than those of < 0.5-km individuals. The offspring of alates with flight experiences of > 1.5 km also had lower fecundity than those produced by individuals that had engaged in flights < 1.5 km. Our results are therefore consistent both with direct trade-offs between flight and fecundity and a trade-off between flight and fecundity via maternal effects.