Plant Volatile Organic Compounds Attractive to Monolepta signata (Olivier)

Plant volatiles play a critical role in mediating insect host location behavior and offer eco-friendly alternatives for chemical control. Monolepta signata is a widespread phytophagous pest in East Asia that poses a significant threat to various crops. In this study, we evaluated the electrophysiological and behavioral responses of adult M. signata to 26 binary and ternary mixtures of 13 plant-derived volatile compounds extracted from cotton and corn leaves. Electroantennogram (EAG) recordings revealed that females exhibited the strongest responses to mixtures 20, 23, and 12, whereas males were the most responsive to mixtures 26, 19, and 4. Y-tube olfactometer assays showed significant behavioral attraction of females to mixtures 1, 20, 23, and 26, and males to mixtures 19, 22, and 23. Field trials demonstrated that mixtures 22, 23, and 26 attracted significantly more adults than the control, with mixture 23 (α-phellandrene + trans-2-hexen-1-ol + 1-heptene) achieving the highest trap capture. These findings highlight the potential of specific volatile blends, especially ternary mixtures, as effective attractants of M. signata, and support their application in environmentally sustainable pest monitoring and management strategies.