Effects of Priming Rice Seeds with Decoyinine on Fitness Traits and Virus Transmission Ability of the Small Brown Planthopper, <i>Laodelphax striatellus</i>

Abstract

Laodelphax striatellus is a notorious sap-feeding insect that also serves as a vector of rice stripe virus (RSV) and is responsible for a significant decline in rice yield. Pesticide application remains a crucial strategy for controlling insect pests. In recent years, the utilization of biopesticides has gained attention due to their eco-friendliness and suitability for controlling insect pests and pathogens in agriculture. The present study aimed Figureto evaluate the potential efficacy of a microbial pesticide, decoyinine (DCY), as a seed priming agent in rice against SBPH’s biology, feeding behavior, and RSV transmission ability in the laboratory. Here, we revealed that the body weight of females and males and honeydew extraction of RSV-virulent SBPH were (22.50%, 25.0%, and 23.25%, respectively) significantly lower than non-virulent SBPH. Meanwhile, the fecundity of RSV-virulent SBPH females was significantly higher (8.24%) than non-virulent SBPH. However, nymphal survival and RSV transmission (horizontal and vertical) were found to be non-significantly affected by DCY application. Furthermore, DCY-primed rice seedlings significantly prolonged the time period and frequency of the electrical penetration graph (EPG) feeding waveforms (np, N2, and N3), and also reduced the time period of the waveform (N4-b) for both RSV-virulent and non-virulent SBPH strains with reduced RSV inoculation. The recent study provides new insights for DCY application in rice against SBPH by reducing fecundity, body weight, and honeydew contents, which might contribute to modern integrated pest management.

Keywords

• small brown planthopper (SBPH)
• decoyinine (DCY)
• electrical penetration graph (EPG)
• fecundity
• RSV transmission