Performance of the newly invasive fall armyworm Spodoptera frugiperda on
different food plants
Abstract
The influence of four food plants (corn, peanut, soybean and sugarcane)
on life-history traits of the fall armyworm (FAW) Spodoptera frugiperda
was examined in the laboratory at 25±1 °C and a photoperiod of L:D 15:9
(15 h light:9 h dark). The leaf contents of the total flavonoids,
reducing sugars, sucrose and C/N ratio were also tested. 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. However, FAW
successfully completed its whole life cycle and exhibited higher
fecundity in peanut, soybean and sugarcane. The FAW showed a protogyny
phenomenon because the pupal development stage was significantly longer
in males than females. There was a positive relationship between pupal
weight and fecundity. However, the relationships between larval
development time and pupal weight and between fecundity and longevity
were different among different food plants. The leaf contents of the
total flavonoids, reducing sugars, and sucrose and the C/N ratio
differed significantly among the different food plants. We discuss the
influences of these leaf nutritional contents on larval development time
and pupal weight. These findings can help us to better understand the
variation in life-history traits of the FAW and may be critical for the
development of strategies to predict infestation levels.