Can Sweet Maize Act as a Trap Crop for Fall Armyworm?

Area of Science:

• Entomology
• Plant-Insect Interactions
• Chronobiology

Background:

• Spodoptera frugiperda (fall armyworm) is a major pest of corn.
• Larvae feed on various corn types, including sweet and fresh varieties.
• The impact of host plant variety on insect rhythms is not well understood.

Purpose of the Study:

• To investigate how long-term feeding on different corn varieties affects the behavioral rhythms of Spodoptera frugiperda.
• To determine the influence of host plant on circadian clock gene expression in fall armyworms.
• To inform pest control strategies in corn-growing regions.

Main Methods:

• Established Spodoptera frugiperda strains by feeding larvae on Zhengdan 958 (normal corn), Zhenghuangnuo (sweet waxy corn), or an artificial diet for nine generations.
• Compared adult behaviors including emergence, movement, foraging, dormancy, mating, and oviposition.
• Analyzed circadian clock gene expression using RT-qPCR.

Main Results:

• Significant differences in six behavioral peak times were observed among the strains.
• Circadian clock gene expression varied significantly across populations and tissues.
• Sweet corn (Zhenghuangnuo) was more favorable for pupation, mating, and oviposition.

Conclusions:

• Host plant variety influences Spodoptera frugiperda circadian rhythms and behaviors.
• Differences in adult insect rhythms due to sweet corn consumption may affect fall armyworm reproduction in key agricultural regions.
• Findings provide insights for developing targeted pest management tactics.