Environmental Entomology (2014) 43, 1286-1294

Tsedal T. Ghebremariam, Kerstin Krüger, Carl F. Reinhardt and Petrus J. Robbertse (2014)
Abiotically-Induced plant morphological changes and host-range expansion in quarantine evaluations of candidate weed biocontrol agents: The case study Conchyloctenia hybrida (Coleoptera: Chrysomelidae)
Environmental Entomology 43 (5), 1286-1294
Abstract: Plant morphological changes mediated by growth conditions are linked to changes in host preference of herbivores. Understanding how these morphological changes influence herbivore feeding is critical in the interpretation of results of host evaluation of candidate weed biocontrol agents in quarantine and improvement of the evaluation system. We determined the effect of plant growth conditions on leaf trichomes and host choice of Conchyloctenia hybrida Boheman, an insect adapted to the removal of trichomes before feeding. The study included four Solanum species: Solanum lichtensteinii Willdenow (natural host of C. hybrida), Solanum mauritianum Scopoli, Solanum melongena L., and Solanum tuberosum L.. Plants were grown in either full sun, shade, a glasshouse, or in a growth-chamber. Plants grown in full sun had a higher leaf trichome density than those in shade or controlled environments. S. mauritianum had the highest trichome density and thickness of trichome layer. In a multiple-choice test using excised leaves, feeding by C. hybrida was higher on Solanum plants grown in the controlled environment as compared with full sun. Trichome removal from leaf surfaces of plants grown in full sun, using adhesive tape, was effective for S. lichtensteinii, S. mauritianum, and S. melongena, but not S. tuberosum. Leaf consumption by C. hybrida increased significantly where manual trichome removal using adhesive tape was effective. Structurally, leaves of S. tuberosum have simple trichomes with basal cells sunken into the mesophyll tissue. When using forceps to remove trichomes of S. tuberosum, mesophyll and vascular tissue remained attached to the trichomes. Generally, the type, density, and mat-thickness of leaf trichomes determined feeding by C. hybrida, but varied with plant species and growth conditions.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: English)
Link to article at publishers website
Database assignments for author(s): Kerstin Krüger

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Solanum mauritianum (weed)
Conchyloctenia hybrida (weed bioagent)	Solanum mauritianum (weed)