Ground beetles can produce orange-scented aromas as predator repellents

Washington, August 14 (ANI): In a new research, scientists have found that ground beetles produce orange scented aromas as predator repellents.

The research by Stevens Institute of Technology Professor Athula Attygalle and his research student, Xiaogang Wu, report for the first time that some ground beetles produce the natural repellent limonene as their major defensive chemical.

An efficient commercial repellent for dogs, cats, some birds, and even mammals such as deer, limonene is a plant product that belongs to group of chemicals called terpenes.

In fact, limonene has been patented as an insect repellent

The active ingredient in the commercial insect repellent "Orange Guard" is (+)-limonene. It is reported that this broad-based insecticide product will cause mortality in most insects within 15 minutes.

The active ingredient d-limonene destroys the wax coating of the insect's respiratory system.

Many higher plants produce essential oils consisting mainly of terpenes to protect themselves from herbivores.

"Terpenes are well known from some insects such as ants, hemipteran bugs, sawflies, and termites. However, terpenes have not been reported from ground beetles," said Attygalle, a professor of Chemistry in the Department of Chemistry, Chemical Biology and Biomedical Engineering.

"We found that the major constituent in the pygidial gland defensive fluid of the ground beetle Ardistomis schaumii is (r)-(+)-limonene, whereas that of closely related species Semiardistomis puncticollis is (S)-(-)-limonene," he said.

This was an unanticipated result, since it is not very common to find the opposite enantiomers (left- and right-handed forms) of the same compound among the secondary metabolites of related species," he added.

Of about 500 carabid species that have been chemically investigated, this is the first report of the presence of such complex mixtures of monoterpenes in their defensive secretions. (ANI)