Host range of Ceutorhynchus assimilis (Coleoptera: Curculionidae), a candidate for biological control of Lepidium draba (Brassicaceae) in the USA

Phenology and temperature‐dependent development of Ceutorhynchus assimilis, a potential biological control agent for Lepidium draba

“…The number of eggs, larvae, dead individuals and exit holes was recorded for each single shoot. The three larval stages were distinguished by measuring their head capsule diameter (see Fumanal et al 2004a).…”

“…Several herbivores associated with L. draba in Europe, including the weevil Ceutorhynchus assimilis (Paykull) [= Ceutorhynchus pleurostigma (Marsham)] (Coleoptera, Curculionidae), show potential for biological control and are currently investigated at CABI Switzerland on behalf of a consortium of mid-western US states (Idaho, Montana, Oregon, South Dakota and Wyoming), British Columbia and two Federal agencies (BLM and USDA-APHIS) (Hinz et al 2014). The phenology of C. assimilis is still not well understood and was only partially studied in southern France (Fumanal et al 2004a). Adults lay their eggs in young, soft roots of the plant, causing the formation of galls, in which the weevil larvae feed and mature.…”

“…Gall making insects, such as C. assimilis, are generally regarded as promising biological control agents, as they often show a high host specificity due to their intimate relationship to their host plant (Harris and Shorthouse 1996). Ceutorhynchus assimilis was first considered as a potential biological control agent for L. draba by Fumanal et al (2004a). Previously, the weevil has been assumed to have a broad host range (Hoffmann 1954), but preliminary host-specificity tests showed that a population found in southern France was only able to complete larval development on L. draba (Fumanal et al 2004a).…”

“…Ceutorhynchus assimilis was first considered as a potential biological control agent for L. draba by Fumanal et al (2004a). Previously, the weevil has been assumed to have a broad host range (Hoffmann 1954), but preliminary host-specificity tests showed that a population found in southern France was only able to complete larval development on L. draba (Fumanal et al 2004a). Molecular analyses confirmed the existence of four distinct clades of C. assimilis (Fumanal et al 2004b).…”

Exotic wildland weeds serve as reservoirs for a newly introduced cole crop pest, Bagrada hilaris (Hemiptera: Pentatomidae)

“…Generally, phylogenetic relatedness, or biochemical or morphological similarities with the target plant are expected to increase the risk of sensitive species to non-target effects (Wapshere 1974;Schaffner 2001;Sheppard et al 2005). Because of this increased risk, as well as the backlash from several well-publicized projects perceived to have unintended negative effects on native species (see Dudley et al 2012;Fowler et al 2012), few programmes had targeted weeds with economically important or ecologically sensitive relatives (Fumanal et al 2004), regardless of the substantial impacts that some have had on agriculture and ecosystems. However, modern molecular tools used to evaluate phylogenetic and chemical relationships that influence host plant use by insects have vastly improved agent selection and specificity, and the overall safety of biological control (Sheppard et al 2005).…”