ABSTRACT Plants and insects are members of diverse ecological communities. Feeding of herbivore insects may damage the host plants indirectly by altering the photosynthetic activity. The objective of this study was to evaluate the physiological changes in citrus plants due to citrus leafminer (CLM) Phyllocnistis citrella Stainton (Gracillariidae: Lepidoptera) larval feeding under field condition. Plants from four economically important citrus cultivars, Citrus reticulata (Kinnow and seedless Kinnow), Citrus tangerines (Fairchild), and Citrus paradisi Macfad (Grapefruit), were selected randomly and leaf damage was assessed through an image analysis technique. The results showed that percent leaf damage was higher at 44.2% on Fairchild compared to other cultivars at 19th day of post-feeding. The reduction in leaf photosynthesis (Pn), stomatal conductance (C), and transpiration rate (E) rates due to larval feeding through 19th day was found consistent in all cultivars except Grapefruit. After 13 days, Pn and gaseous exchange rates in damaged leaves of Grapefruit recovered to some extent but remained significantly lower than in control through 19th day. Reduction in all three physiological parameters in infested leaves was ranged as Fairchild > Kinnow > seedless Kinnow > Grapefruit compared to their level in control. Percent of leaf damage had a strong and negative relation with Pn, C, and E in all citrus cultivars except Grapefruit in which all variables showed a weak relation. Conclusively, P. citrella may cause a serious threat to citrus plants even at lower levels of infestation, and these physiological impairments could be more intense in regions with high P. citrella population.

中文翻译：

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柑橘潜叶虫、柑橘叶螨（鳞翅目：蜻蜓科）侵染柑橘植物的生理特征

摘要 植物和昆虫是不同生态群落的成员。食草动物昆虫的饲养可能会通过改变光合作用活动间接损害寄主植物。本研究的目的是评估在田间条件下由于柑橘潜叶虫 (CLM) Phyllocnistis citrella Stainton (Gracillariidae: Lepidoptera) 幼虫摄食引起的柑橘植物生理变化。随机选择来自四种经济上重要的柑橘品种 Citrus reticulata (Kinnow 和无籽 Kinnow)、柑橘 (Fairchild) 和 Citrus paradisi Macfad (Grapefruit) 的植物，并通过图像分析技术评估叶片损伤。结果表明，在喂食后第 19 天，Fairchild 的叶片损伤百分比高于其他品种，为 44.2%。叶片光合作用（Pn）的减少，发现由于幼虫喂养到第 19 天的气孔导度 (C) 和蒸腾速率 (E) 率在除葡萄柚外的所有品种中都是一致的。13 天后，葡萄柚受损叶片的 Pn 和气体交换率有所恢复，但到第 19 天仍显着低于对照。与对照水平相比，受侵染叶片中所有三个生理参数的降低范围为 Fairchild > Kinnow > 无籽 Kinnow > Grapefruit。除葡萄柚外，所有柑橘品种的叶片损伤百分比与 Pn、C 和 E 呈强负相关，葡萄柚的所有变量均呈弱相关。总而言之，即使在较低水平的侵染下，P. citrella 也可能对柑橘植物造成严重威胁，并且这些生理损伤在 P. 高的地区可能更为严重。