Key factors involved in reduction of damage to sunflower by the European sunflower moth in China through late planting

Authors: CHENG, YUNXIA - Chinese Academy Of Agricultural Sciences; Sappington, Thomas; LUO, LIZHI - Chinese Academy Of Agricultural Sciences; LIU, CHENGUANG - Bayannur Station Of Plant Protection And Quarantine; WANG, YONGJUN - Bayannur Station Of Plant Protection And Quarantine; LIU, SHUANGPING - Bayannur Station Of Plant Protection And Quarantine; ZHANG, ZONGZE - Fuzhou Customs District Pr China; WANG, LIJUN - Bayannur Station Of Plant Protection And Quarantine; JIANG, XINGFU - Chinese Academy Of Agricultural Sciences

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2021
Publication Date: 4/22/2021
Citation: Cheng, Y., Sappington, T.W., Luo, L., Liu, C., Wang, Y., Liu, S., Zhang, Z., Wang, L., Jiang, X. 2021. Key factors involved in reduction of damage to sunflower by the European sunflower moth in China through late planting. PLoS ONE. 16(4). Article e0250209. https://doi.org/10.1371/journal.pone.0250209.
DOI: https://doi.org/10.1371/journal.pone.0250209

Interpretive Summary: The European sunflower moth, Homoesoma nebulellum, has created an important biological crisis by attacking sunflower in Bayannur of Inner Mongolia, an important area for cultivated sunflower in China. In 2005, 21% (233,000 ha) of the total cropping area in Bayannur was planted to sunflower, representing 30% of gross agricultural output and 28% of total production of this crop in China. In this study, we focus on three aspects related to a new and highly successful strategy for managing H. nebulellum. Firstly, in experimental small plot trials, we found planting sunflower from 25 May to 5 June significantly suppressed damage by H. nebulellum compared to earlier traditional planting dates. Based on this finding, these delayed planting dates were quickly implemented on an area-wide scale by farmers in Bayannur beginning in 2007. Astonishing and dramatic regional decreases in infestation and production losses were realized within 2 years, and have been maintained since 2009. Secondly, experiments showed that the key factor influencing level of damage by this moth is temporal overlap between the first two days of the female's 10-day egg-laying period and the beginning of flowering within the sunflower seed head. This information will be used by university and government scientists interested in close relatives of this pest, or in development of other pest management tactics consistent with environmental and ecological protection in agro-ecosystems.

Technical Abstract: Beginning in 2005, the European sunflower moth, Homoesoma nebulellum, represented an important biological crisis by attacking sunflower in Bayannur, an important area for cultivated sunflower in northern China. Delaying planting until 25 May to 5 June dramatically suppressed H. nebulellum infestations area-wide. Within two years of implementing delayed planting, regional infestation area decreased from 72% to 1.5%, and production losses from 7000 to 51 tons. Temporal overlap between oviposition period and beginning of flowering was the key factor influencing level of damage. Rate of sunflower seed infestation was significantly correlated with number of trapped adults weighted by proportion of daily oviposition during the first two days of oviposition. Desynchronization of the first two days of blooming and peak adult presence underlies effectiveness of delayed planting.