Journal of Economic Entomology (2002) 95, 952-957

Yong-Lak Park and Joon-Ho Lee (2002)
Leaf cell and tissue damage of cucumber caused by twospotted spider mite (Acari: Tetranychidae)
Journal of Economic Entomology 95 (5), 952-957
Abstract: To quantify the damage caused by twospotted spider mite, Tetranychus urticae Koch, feeding on cucumber, Cucumis sativus L., leaf-cell and -tissue damage was assessed. On the abaxial leaf surface, adult T. urticae could feed through the spongy parenchyma and part of the palisade parenchyma of the leaf, while immature T. urticae could feed only through the sponge parenchyma. T. urticae punctured individual epidermal cells and consumed the contents of the mesophyll cells. Injured leaves had more empty space in the spongy parenchyma and fewer chloroplasts per cell. Damage also occurred even in the adjacent uninjured parenchyma cells without additional T. urticae feeding injury. Net photosynthetic rate, total chlorophyll content, and greenness of the leaf were significantly affected by feeding as quantified by mite-days. The percent loss of these parameters increased linearly or nonlinearly as mite-days increased, regardless of mite developmental stages. At 1,000 mite-days per 6 cm², net photosynthetic rate was reduced by ~50 and 95%, total chlorophyll content was reduced by ~55 and 80%, and greenness was reduced by ~50 and 80% by feeding by immature and adult T. urticae, respectively.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Joon-Ho Lee, Yong-Lak Park

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus urticae	Cucumber (Cucumis sativus)