Antifeedant and toxic effects of drimanes on Colorado potato beetle larvae

Abstract

Among the drimane compounds tested, the dialdehydes polygodial and warburganal were the most active as antifeedants against Colorado potato beetle larvae, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), in a dual‐choice assay with potato, Solanum tuberosum L., leaf discs. Lactones were less effective. Direct observations showed that decreased feeding on leaf discs treated with polygodial and warburganal was accompanied by increased locomotory activity. Topical application of these two compounds on the insect's cuticle decreased food intake of untreated leaf discs, indicating that besides deterrent effects, toxic properties of these molecules influence feeding behaviour.

Leaf surface compounds of the potato (Solanum tuberosum) and their influence on Colorado potato beetle (Leptinotarsa decemlineata) feeding

“…A deterrent effect on the feeding behavior of CPB was also reported for terpenes, even though the concentrations of these compounds used in the tests were higher than in our experiments. For example, drimane sesquiterpenes were found to inhibit CPB larval feeding at concentrations of c. 5 mg/cm 2 (Gols et al 1996). Two sesquiterpenes isolated from Senecio palmensis displayed antifeedant activity against CPB adults and larvae at 100 mg/cm 2 (Gonzalez- Coloma et al 1995).…”

Preparation of 9α‐Fluorinated Sesquiterpenic Drimanes and Evaluation of Their Antifeedant Activities

“…This compound is a naturally occurring drimanic sesquiterpenic lactone known as isodrimenin that was first isolated from the stem bark of the South American Drimys species [35] and exhibits significant feeding inhibition activity. [36] The formation of 24 in the above reaction represents an apparently intramolecular S N 2Ј process involving a disfavoured 5-endotrig cyclization reaction. Although this type of cyclization is contrary to the generally accepted Baldwin rules, there are some examples in the literature of somewhat related anti-Baldwin cyclization reactions.…”

“…Although obtained in low yield, the availability of the hydroxy ester 29 allowed the ready preparation of 9α-fluorodrimenin (17; Scheme 5), the 9α-fluoro analogue of the bioactive drimane sesquiterpene drimenin (9). [36,50] Thus, base-promoted lactonization of hydroxy ester 29 by treatment with 8-diazabicyclo [5.4.0]undec-7-ene (DBU) in benzene at room temp. in the presence of 3 Å molecular sieves afforded 9α-fluorodrimenin (17) in a yield of 85 %.…”

Comparison of the chemical composition of three species of smartweed (genus Persicaria) with a focus on drimane sesquiterpenoids

“…This dialdehyde has been also found in bryophytes and pteridophytes (Asakawa et al, 2001) and it is even synthesized by Mediterranean nudibranchs of the genus Dendrodoris, where it plays a role as fish antifeedant (Avila et al, 1991). Polygodial has a pungent taste to mammals (Escalera et al, 2008;Kubo and Ganjian, 1981), and acts as an antifeedant for a number of herbivorous insects (Jansen and de Groot, 2004), including aphids (Asakawa et al, 1988;Powell et al, 1995), Colorado potato beetle (Caprioli et al, 1987;Gols et al, 1996), and moth larvae (Caprioli et al, 1987;Kubo and Ganjian, 1981). The neurological mode of action of polygodial is by opening TRPA1 ion channels on sensory neurons (Escalera et al, 2008).…”