Introduction to Poplar defense against insect herbivores / Introduction de Poplar defense against insect herbivores

Leaves display an enormous array of sizes and shapes. Although these attributes appear to have evolved primarily in response to abiotic conditions in the plant’s habitat, the importance of insect herbivores as additional selective agents is still poorly understood. A necessary requirem ent for leaf size and shape to evolve in response to attack by insects is that insects must respond to and/or be affected by, leaf morphology. We tested leaf-shape preferences in adult flea beetles ( Phyllotreta spp.) feeding on the highly variable rosette leaves of Capsella bursa-pastoris . Contrary to theoretical expectation (Brown & Lawton 1991), leaves with deeply lobed margins were more intensely damaged, both in field-collected and experimental plants. In two ancillary experiments with Capsella , we found that Spodoptera caterpillars showed no preferences for leaf shape, but that adult vine weevils ( Otiorhynchus sulcatus ) did, preferring (as predicted), undivided over divided leaves. We conclude that Brown & Law ton’s (1991) hypothesis is at best weakly supported by laboratory data for vine weevils, refuted by laboratory data for Spodoptera , and consistently refuted by both laboratory and field data for flea beetles. Although the experiment tried to reduce confounding variables to a minimum, interpretation was complicated by correlations between leaf shape and other developmental parameters of the plants, and highlights the difficulty of disentangling leaf-shape effects from other confounding factors.

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Does lignin modification affect feeding preference or growth performance of insect herbivores in transgenic silver birch (Betula pendula Roth)?

Planta ◽

10.1007/s00425-005-0002-5 ◽

2005 ◽

Vol 222 (4) ◽

pp. 699-708 ◽

Cited By ~ 22

Author(s):

Heidi Tiimonen ◽

Tuija Aronen ◽

Tapio Laakso ◽

Pekka Saranpää ◽

Vincent Chiang ◽

...

Keyword(s):

Growth Performance ◽

Betula Pendula ◽

Feeding Preference ◽

Silver Birch ◽

Insect Herbivores ◽

Betula Pendula Roth ◽

Lignin Modification

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Herbivory in the epiphyte, Vriesea sanguinolenta Cogn. & Marchal (Bromeliaceae)

Journal of Tropical Ecology ◽

10.1017/s0266467400001747 ◽

2000 ◽

Vol 16 (6) ◽

pp. 829-839 ◽

Cited By ~ 25

Author(s):

GEROLD SCHMIDT ◽

GERHARD ZOTZ

Keyword(s):

Leaf Area ◽

Current Knowledge ◽

Insect Herbivores ◽

Vascular Epiphytes ◽

Herbivore Attack ◽

Tropical Flora ◽

Herbivore Pressure

Although herbivory in ground-rooted flora is well documented, current knowledge of the herbivore pressure on vascular epiphytes remains mostly anecdotal. Here, we present the results of a 3-year study on the herbivory in a population of the epiphytic bromeliad Vriesea sanguinolenta. In different years, 26–61% of all epiphytes showed traces of herbivore attack, while up to 4.4% of the entire leaf area of the epiphyte population was consumed annually. The recorded levels of damage to photosynthetic tissue, mostly caused by the larvae of Napaea eucharilla (Riodinidae, Lepidoptera), indicate that vascular epiphytes may be regularly and sometimes even lethally attacked by insect herbivores. The level of damage is comparable to ground-rooted tropical flora, which certainly does not support the prevalent notion of low and negligible levels of herbivory in vascular epiphytes.

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