EcoLaVerna Integral Restoration Ecology, Bridestown, Kildinan, Co. Cork, Ireland.
Universidad Católica del Maule, Facultad de Ciencias Agrarias y Forestales, Escuela de Agronomía, Casilla 7-D, Curicó, Chile.
Environ Entomol. 2021 Aug 12;50(4):929-939. doi: 10.1093/ee/nvab034.
Two stem-boring moths, the yellow stemborer (YSB) Scirpophaga incertulas (Walker), and the striped stemborer (SSB), Chilo suppressalis (Walker), damage rice in Asia. YSB is the dominant species in much of tropical Asia. Both species are oligophagous on domesticated and wild rice. We investigated the roles of host plant preferences and larval performance in determining the larval densities of both species in rice plots. In screenhouse experiments, YSB showed significant preference-performance coupling. Adults preferred high-tillering rice varieties during early vegetative growth. In contrast, SSB did not demonstrate oviposition preferences under the same screenhouse conditions, but did oviposit less on the wild rice Oryza rufipogon Griff. than on domesticated rice varieties during a choice experiment. Despite differences in preference-performance coupling, larval survival and biomass across 10 varieties were correlated between the two species. YSB and SSB larvae occurred in relatively high numbers on rice varieties with large tillers (IR70, IR68, and T16) in wet and dry season field experiments. However, whereas YSB was the dominant species on IR68 and IR70, it was relatively less abundant on T16, where SSB dominated. Results suggest that YSB preferentially attacked fast-growing rice varieties with high tiller numbers early in the crop cycle. Meanwhile SSB, which has weak preference-performance coupling, occurred in rice plants with large tillers that were relatively free of YSB later in the crop cycle. These factors may allow the species to coexist. We discuss the implications of proximate and ultimate factors influencing stemborer co-occurrence for the sustainable production of rice in tropical Asia.
两种蛀茎蛾，黄螟（YSB）Scirpophaga incertulas（Walker）和条螟（SSB），Chilo suppressalis（Walker），在亚洲损害水稻。YSB 是热带亚洲大部分地区的优势物种。两种物种都对驯化和野生稻有寡食性。我们调查了寄主植物偏好和幼虫表现在确定两种物种在稻田幼虫密度中的作用。在温室实验中，YSB 表现出显著的偏好-表现耦合。成虫在早期营养生长期间对分蘖高的水稻品种有明显的偏好。相比之下，在相同的温室条件下，SSB 没有表现出产卵偏好，但在选择实验中，它在野生稻 Oryza rufipogon Griff.上的产卵量比在驯化品种上的产卵量少。尽管偏好-表现耦合存在差异，但在 10 个品种中，两种物种的幼虫存活率和生物量都存在相关性。在干湿季节田间试验中，YSB 和 SSB 幼虫在分蘖较多的水稻品种（IR70、IR68 和 T16）上数量相对较多。然而，在 IR68 和 IR70 上，YSB 是优势种，而在 T16 上，SSB 则相对较少，这表明 YSB 优先攻击在作物周期早期分蘖数较高、生长迅速的水稻品种。同时，SSB 具有较弱的偏好-表现耦合，在作物周期后期，大量分蘖、相对较少 YSB 的水稻植株中出现。这些因素可能允许这两个物种共存。我们讨论了影响蛀茎蛾共存的近因和远因，这些因素对热带亚洲水稻的可持续生产具有重要意义。
