| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4505718 | Crop Protection | 2015 | 6 Pages |
•A. purpurata essential oil is composed mainly by mono- and sesqui-terpenes.•Major compounds were β- and α-pinene, trans-caryophyllene, camphene, and 7-epi-α-selinene.•The oil showed antinutritional effects when ingested by Sitophilus zeamais adults.•No toxicity was observed when the oil was applied directly on the cuticle of insects.•The oil was toxic to insect adults by fumigation with LC50 = 41.4 μL/L in air.
The maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae), is a cosmopolitan pest that causes extensive and irrecoverable damage to storage grains. This work investigated the chemical composition, insecticidal activity, feeding-deterrent and repellent effects of an essential oil from Alpinia purpurata inflorescences against S. zeamais. Analysis by gas chromatography coupled to mass spectrometry (GC–MS) revealed the presence of 30 volatile constituents (mainly mono- and sesqui-terpenes). The main compounds found in the oil were β-pinene, α-pinene, trans-caryophyllene, camphene, and 7-epi-α-selinene. When ingested by S. zeamais adults, the A. purpurata oil did not kill the insects but disrupted their nutritional status since biomass gain rate and efficiency in conversion of ingested food were both negative or near zero. A weak feeding-deterrent effect was also detected. No toxicity was observed when the oil was applied directly on the cuticle of S. zeamais adults. The fumigant toxicity assay revealed that the A. purpurata oil killed S. zeamais adults with LC50 = 41.4 μL/L in air; however, no repellent property was detected. The essential oil from A. purpurata inflorescences was toxic to S. zeamais adults by fumigation and due to interferences in digestion of food. Fumigant toxicity is likely due to the presence of some monoterpene hydrocarbons and oxygenated monoterpenes.
