Effects of food plants on life-history traits of the newly invasive fall
armyworm Spodoptera frugiperda in Southeast China
Abstract
The fall armyworm (FAW) Spodoptera frugiperda has invaded Jiangxi
Province, Southeast China for the past three years. Although the FAW
displays a very wide host range, one of its main host plants in Jiangxi
Province is still field corn. This study systematically investigated the
effects of food plants (corn, peanut, soybean and sugarcane) on
life-history traits of FAW and tested the leaf contents of the total
flavonoids, reducing sugars, sucrose and C/N ratio. We found that the
FAW fed on corn leaves showed significantly shorter larval and pupal
development times, larger body weight, higher growth rate, lower weight
loss, smaller SSD, shorter preoviposition period and higher fecundity
than those fed on peanut, soybean and sugarcane leaves. The pupal
development stage was significantly longer in males than females,
showing a protogyny phenomenon. Food plants changed the relationships
between larval development time and pupal weight and between fecundity
and longevity. The corn leaves showed significantly higher contents of
reducing sugars and sucrose, lower content of the total flavonoids, and
a moderate C/N ratio, suggesting that the corn leaf tissues are more
nutritive. These findings may help us to understand why the FAW mainly
infests corn plants and may be critical for the development of
strategies to predict infestation levels.