Interpreting Ambiguous Results of Host-Specificity Tests in Biological Control of Weeds: Assessment of Two Leptinotarsa Species (Chrysomelidae) for the Control of Solanum elaeagnifolium (Solanaceae) in South Africa

Natural Enemies of Brazilian Peppertree (Sapindales: Anacardiaceae) from Argentina: Their Possible Use for Biological Control in the USA

“…Bennett, Univ. of Florida, unpublished report, G. S. W., unpublished data) suggest that this leaf-feeding moth has a narrow field host range. Under restricted conditions, many herbivorous insect species display extended host ranges (Harris & Zwölfer 1968;Wapshere 1989;Cullen 1990;Shepherd 1990;Olckers et al 1995;McCoy et al 2003). The acceptance by T. elegans of Pistacia species and most of the native Anacardiaceae species included in the first host-specificity tests could be a result of the artificial conditions in cages.…”

Replacement value of Solanum elaeagnifolium for alfalfa hay offered to growing goats

“…This deep-rooted perennial forb is also one of the most difficult weeds to eradicate. Mechanical, herbicidal, and biological methods often fail because of its network of creeping horizontal and deep vertical roots (Olckers et al, 1995). The phenotypic plasticity of this plant further allows switiching to prostrate growth under repeated cutting (Mekki, 2007).…”

Abiotically-Induced Plant Morphological Changes and Host-Range Expansion in Quarantine Evaluations of Candidate Weed Biocontrol Agents: The Case StudyConchyloctenia hybrida(Coleoptera: Chrysomelidae)

“…In addition to their physiological role in reducing water loss due to transpiration (Young and Smith 1980), trichomes have been reported to play a role in plant defense (Levin 1973, Johnson 1975, Southwood 1986, although contradictory results were reported by Andres and Connor (2003). The fact that full-sun plants of S. mauritianum were accepted (with minimal feeding) only under a no-choice setting (control treatment of the trichome removal trial) where there was more conÞnement (sleeve cages) could be attributed to changes in herbivore behavior because of captivity (Blossey et al 1994, Olckers et al 1995, Heard 2000.…”

“…The main focus in understanding the underlying cause for such ambiguous results has been on insect behavioral aspects such as disruption of host perception owing to captivity, motivational status, prior experience, and learning (Blossey et al 1994, Olckers et al 1995, Heard 2000, Withers et al 2000, Sheppard et al 2005), whereas only a few studies have focused on the aspect of changes in plant quality owing to the growth conditions (van Klinken 1999, Diaz et al 2011 in environmental chambers, glasshouses or shade nets where test plants are grown Borea 2009, Hakizimana andOlckers 2013). …”