PARIS — About five years ago, Alain Lenoir, a researcher at François Rabelais University in Tours, France, was studying the biochemical process by which ants differentiate between friends and foes.
Scientists had come to understand that the insects used their antennae to sense the makeup of the hydrocarbons of other ants’ cuticles. Using chemical analyses like gas chromatography, Dr. Lenoir had begun focusing in particular on hydrocarbons on Lasius niger, the common black ant.
Dr. Lenoir, who has been studying ants since 1968, found something unexpected: in addition to the hydrocarbons, the analysis was consistently revealing the presence of plastic additives called phthalates, and not just in a few specimens – all of them.
Other scientists had reported such findings, he said, but he had brushed off the presence of those chemicals as contamination that occurred in the lab.
Intrigued, Dr. Lenoir, today an emeritus professor, decided to follow up with a new study. The results, published in last month’s issue of Science of the Total Environment, an academic journal, confirmed what he had already come to fear.
All of the ants that he and his team studied were contaminated with phthalates, regardless of where the insects originated. For example, the chemical made up as much as 0.59 percent of the substances on the cuticles of ants that had just been collected in a field near Tours. Read more…
Associated PressThe lowly fire ant on the tip of a pencil.
More on the biodiversity front:
For years, scientists tracking global patterns in biodiversity have focused on the distribution of plants, birds and mammals to identify areas that are conservation priorities. In reality, however, it is the often-hidden world of insects that represents most of the planet’s biodiversity. And the greatest diversity among the creepy and the crawly is not always concurrent with that of larger flora and fauna.
Much is simply unknown about how many insect species are out there and where the so-called biodiversity hot spots for them occur.
In an attempt to fill in some of the knowledge gap, a team of researchers from North Carolina State University has compiled data from around the world on diversity patterns for 300 ant genera — ants are among the most abundant insect groups in many ecosystems — to size up what is and is not known. This week the study was published online in the Proceedings of the National Academies of Science.
The researchers compared known diversity patterns of ants with predictions of ant diversity patterns, using on two different models – one based on the distribution patterns in surrounding areas, and one based on environmental conditions in a given region.
While the two models did not agree perfectly, there were areas that both models indicated should have many more ant species than have been documented to date. Parts of West Africa, southeastern Africa, northeastern Brazil, southern Mexico and Southeast Asia were the regions least explored — or, as the researchers put it, “hot spots for discovery.” Over all, the models estimated that about 2,400 occurrences of ant genera are awaiting documentation around the world – and these involve species that are already known to science, not species yet to be discovered. Read more…