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谷类作物，其稳产对于国家及全球粮食安全至关重要。害虫是影响玉米产量与品质的关键因素之一，因此在不同生育阶段针对害虫实施及时防控措施后，评估其挽回的产量与品质损失具有重要意义。本研究针对我国南方地区玉米主要害虫的种群动态展开调查，并评估了不同生育阶段对主要害虫实施有效防控后玉米的产量与品质表现。结果显示：秋玉米发生最为严重的害虫为草地贪夜蛾（fall armyworm, FAW，学名Spodoptera frugiperda，隶属鳞翅目（Lepidoptera）夜蛾科（Noctuidae））；甲氨基阿维菌素苯甲酸盐（emamectin benzoate）、溴虫腈（chlorfenapyr）、氯虫苯甲酰胺（chlorantraniliprole）对草地贪夜蛾均具有良好防控效果。若在玉米4叶期（V4）未实施任何防控措施，则果穗重量损失达10.02%；若分别在抽雄期（VT）与疱粒期（R2）未实施防控措施，危害指数分别下降80.45%和76.09%。此外，若在玉米全生育期均未实施害虫防控措施，则玉米籽粒中的单宁含量将升高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危害效应的认知，并为科学及时防控玉米害虫、减少化学农药的不合理施用提供了理论依据。