2 new species of ‘leaping’ beetles found in New Caledonia

WASHINGTON - Spanish researchers have discovered two more species of ‘leaping’ beetles, also called ‘flea’ beetles, in New Caledonia, in the western Pacific - Arsipoda geographica and Arsipoda rostrata.

Till date, only five species of these beetles, out of a global total of 60, had been discovered.

The newly discovered herbivorous beetles feed on plants that the scientists have still not found on the archipelago.

“The study, financed by the National Geographic, went some way beyond merely classifying species, and investigated the ecology of these herbivorous insects with a prodigious leaping capacity, which they use to avoid their predators,” said Jesus Gomez-Zurita, lead author of the study and a researcher at the Institute of Evolutionary Biology (CSIC-UPF).

The researchers, from Spain and New Caledonia, used previously developed molecular tools in order to classify the DNA sequences of the animals’ diet, in particular chloroplast DNA (which is exclusive to plants).

The team used plant matter remains found in the digestive tract of the insects to extract their DNA.

According to the study, this technique made it possible to discover that one of the new species, Arsipoda geographica, which measures three millimetres, feeds on a tropical plant in the mountains (Myrsinaceae), while Arsipoda isola, which is the same size, feeds on another plant (Ericaceae) in the southern jungles of the island.

“The strangest thing is that the DNA sequences of the plants are from botanical species that have still not been found on the archipelago. This provides indirect evidence of the existence of an enigmatic botanical diversity, which should be more than expected on an island with a wealth of lush vegetation,” said Gomez-Zurita, who has been studying beetles for 20 years.

The study, which is the first in this research line focusing on the Chrysomelidae family (known as ‘leaf beetles’ because they feed primarily on plants), made it possible to collect more than 2,000 beetle samples on the island of Grande Terre, compare them with other species, and carry out a phylogenetic analysis.

“The interest in New Caledonia has recently been renewed as a result of the discovery that the archipelago may have remained completely submerged over a lengthy period up until the Oligocene (more than 23.5 million years ago), when it emerged again, which would mean its fauna and flora originated much more recently than had previously been speculated”, said Gomez-Zurita.

The study is published in the Journal of Natural History. (ANI)