A Preliminary Evaluation of Panicum sarmentosum, A Local Grass Species Potentially Used as a Trap Crop for Controlling Fall Armyworm

Abstract Currently, the invasive pest Spodoptera frugiperda poses a significant risk to maize crops, as it has the potential to lead to complete yield loss if not properly controlled. This study aimed to explore the potency of Panicum sarmentosum, a local grass in Central Sulawesi, Indonesia, as a trap crop to combat this voracious pest. The feeding preference test (two-choice and no-choice test) was conducted in a Completely Randomized Design (CRD) consisting of five forage grasses, i.e. P. sarmentosum, Brachiaria mulato, Pakchong, Pennisetum purpureum, and Zea mays as a control for comparison of their potential as trap crops. The leaf area consumed by S. frugiperda and the growth of S.frugiperda fed on grass leaves were measured to evaluate their suitability as the host plants. The results revealed that although maize leave was the most preferred by FAW larvae to consume, the sarmentose panicum leaves were also chosen by this pest. P. sarmentosum leaf, was the third-ranked choice after maize and Pakchong leaves in the two-choice tests, while in the no-choice test, it was the second preference. The FAW larvae feeding on P. sarmentosum grow and develop surpass than those on mulato grass, supporting that this local grass is suitable as feed and supports the growth of FAW. These results indicated that P. sarmentosum might be used as a trap crop against FAW as one sustainable control method for this maize pest, although further tests are still needed. Keywords: Fall armyworm, feeding preferences, trap crops, local grass, P. sarmentosum