flavones in corn silks & resistance to insect attacks

Flavone contents differed in silks of three maize lines with different resistance to larvae of fall amyworm (FAW), Spodoptera frugiperda Smith, and Southwestern corn borer (SWCB), Diatraea grandiosella Dyar. The main compound in the resistant (CML 67) and in the intermediate (CML 135) lines was apimaysin. In the susceptible line (CML 131) the main compound was 3-methoxymaysin, which was absent from the other two lines. The same distribution pattern was found in the infested plants. The variation in flavone concentration among the 3 lines and among plants infested with Spodoptera frugiperda and Diatraea grandiosella, suggests a different defense mechanism of the plant against each of the two insects.