Reay-Jones F P F, Wilson L T, Showler A T, Reagan T E, Way M O
Department of Entomology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
Environ Entomol. 2007 Aug;36(4):938-51. doi: 10.1603/0046-225x(2007)36[938:roopia]2.0.co;2.
Oviposition preference studies of the Mexican rice borer, Eoreuma loftini (Dyar), on sugarcane, Saccharum spp., and rice, Oryza sativa L., showed that drought stressed sugarcane was 1.8-fold more attractive based on egg masses/plant than well watered sugarcane. The E. loftini susceptible sugarcane cultivar LCP 85-384 was 1.6-fold more attractive than HoCP 85-845 based on numbers of eggs per egg mass. Egg masses were 9.2-fold more abundant and 2.3-fold larger on sugarcane than on rice. Rice, however, was preferred to sugarcane on a plant biomass basis. Oviposition on sugarcane occurred exclusively on dry leaf material, which increased under drought stress. Egg masses per plant increased on drought stressed sugarcane and were correlated with several foliar free amino acids essential for insect growth and development. The more resistant (based on injury) but more attractive (based on oviposition) rice cultivar XL8 had higher levels of several free amino acids than the susceptible cultivar Cocodrie. The association of host plant characteristics to oviposition preference is discussed. Projected oviposition patterns relative to sugarcane and rice production areas were estimated for Texas and Louisiana based on the availability of each host in different regions of each state. These results suggest that, where sugarcane and rice co-occur, the majority of eggs would be found on sugarcane early in the season, because of this crop's substantially greater biomass compared with rice. Abundance later in the season would also favor sugarcane; however, the abundance on rice would be greater than expected solely based on host availability, largely because of the greater preference per gram of rice plant dry weight.
对墨西哥稻螟（Eoreuma loftini (Dyar)）在甘蔗（Saccharum spp.）和水稻（Oryza sativa L.）上的产卵偏好研究表明，基于每株卵块数量，干旱胁迫下的甘蔗比水分充足的甘蔗吸引力高1.8倍。基于每个卵块的卵数，对墨西哥稻螟敏感的甘蔗品种LCP 85 - 384比HoCP 85 - 845的吸引力高1.6倍。甘蔗上的卵块数量比水稻上多9.2倍，且卵块大小是水稻上的2.3倍。然而，以植物生物量为基础，水稻比甘蔗更受青睐。甘蔗上的产卵仅发生在干燥的叶片材料上，干旱胁迫下这种情况会增加。干旱胁迫下的甘蔗上每株卵块数量增加，且与昆虫生长发育所必需的几种叶片游离氨基酸相关。抗性更强（基于伤害）但更具吸引力（基于产卵）的水稻品种XL8比易感品种Cocodrie含有更高水平的几种游离氨基酸。讨论了寄主植物特征与产卵偏好的关联。根据德克萨斯州和路易斯安那州每个州不同地区每种寄主的可获得性，估计了相对于甘蔗和水稻产区的预计产卵模式。这些结果表明，在甘蔗和水稻共存的地方，由于甘蔗的生物量与水稻相比大得多，在季节早期大部分卵会产在甘蔗上。季节后期的丰富度也有利于甘蔗；然而，水稻上的丰富度将大于仅基于寄主可获得性所预期的，这主要是因为每克水稻植株干重的偏好性更高。
