Maize yield and quality response to Lepidoptera pest control at different periods

Maize (Zea mays L.)is a majorcereal crop worldwide, and itsstable production is essential fornational and global food security. Pests are among the keyfactors affecting the yield and quality of maize. Therefore, it is crucial toevaluate the recovery of yield and quality losses when implementingtimely control measures against pests during different periods. In this study,we investigated the population dynamics of main pests for maizein south China, and assess the yield and quality of maize treated by effectivecontrol to main pests during different periods. Results showed that fall armyworm (FAW) Spodoptera frugiperda(Lepidoptera, Noctuidae) was the most severepest of autumn maize, and emamectin benzoate, chlorfenapyr, chlorantraniliprole were effective in controlling FAW.There was a10.02% loss of ear weight when no control measure was taken at the 4th-leaf stage (V4), and there were 80.45% and 76.09% decreasesof the damage index when no control measure was taken at tasseling stage (VT) and blister stage (R2), respectively. Additionally, the tannin content in maize kernels increasedby 26.28% when no pest control measure had been taken throughout the whole stage of maize. These findingsassisted farmers in increasing their knowledge regarding the detrimental effects caused by FAW and other Lepidoptera pests, and provided a theoretical basis for reasonable and timely control of maize pests and reducing the indiscriminate use of chemical pesticides.

玉米（Zea mays L.）是全球范围内的主要粮食作物，其稳定生产对国家及全球粮食安全至关重要。害虫是制约玉米产量与品质提升的关键因素之一，因此评估不同时期及时采取害虫防控措施后产量与品质损失的挽回效果，具有重要意义。本研究调查了华南地区玉米主要害虫的种群动态，并评估了不同时期针对主要害虫采取有效防控措施后的玉米产量与品质表现。结果显示，草地贪夜蛾（FAW，Spodoptera frugiperda，鳞翅目夜蛾科）是秋玉米的首要为害虫种，甲氨基阿维菌素苯甲酸盐、溴虫腈、氯虫苯甲酰胺对其防控效果显著。在四叶期（V4）未采取防控措施时，玉米穗重损失达10.02%；而在抽雄期（VT）与浆粒期（R2）未采取防控措施时，虫害指数分别下降80.45%和76.09%。此外，全生育期未实施害虫防控措施时，玉米籽粒单宁含量升高26.28%。本研究结果有助于提升农户对草地贪夜蛾及其他鳞翅目害虫为害效应的认知，并为合理及时开展玉米害虫防控、减少化学农药滥用提供理论依据。