“Normally, we distinguish insects from each other by their appearance, but cuckoo wasps are so similar to each other that it makes it difficult.“, plague the Norwegian researcher Frode Ødegaard in a statement. Despite everything, he and his team managed to get their hands on a hitherto unknown species that they present in the journal Insect Systematics and Diversity.
Beautiful insects with vibrant colors
The Chrysididae also called “wasp-cuckoo”, have the annoying tendency to lay eggs in the nests of other insects such as bees or wasps. The larvae develop faster than their neighbors and therefore hatch before the host’s eggs. They can then swallow the eggs, larvae but also the food that the host had placed in the nest. The beautiful colors of these wasps have made them little stars on the Internet. As beautiful as they are, they represent a real headache for entomologists: for a long time, they struggled to know which characteristics were specific to a species and which were specific to a single specimen. And this process can still be complicated today, even by scanning DNA. Thus, researchers have just differentiated between two species of cuckoo wasps.
Two different species with two different “languages”
“In this case, we had two cuckoo wasps with microscopic differences in appearance and very small differences in DNA.“, remarks Frode Ødegaard. To differentiate them, the researchers therefore looked at their language. Of course, it is not made up of words but rather of pheromones, however it is indeed a way of communicating : in insects, these compounds are called cuticular hydrocarbons. And closely related species often have completely different chemical languages to prevent hybridizations. Here again, the cuckoo wasps have their little peculiarity: “When one lives as a parasite, it is important not to be discovered, and therefore the cuckoo wasp has also learned the language of its host.“, underlines the Norwegian researcher.
The two target species have different hosts and therefore different cuticular hydrocarbons. And it was by studying them that researchers were able to conclude that they belong to distinct species. If one was already baptized Chrysis brevitarsis, it was necessary to name the second. She was named Chrysis parabrevitarsis, which means “the one next to the brevitarsis“in order to reflect the proximity between the two insects. For the moment, only one specimen of this new species has been discovered, on the Lista peninsula in the county of Agder in Norway. And this specimen has been pinned and integrated into a insect collection … “Even with today’s advanced methods, the use of live animals for studies like this is not possible and the collection of individual specimens fortunately has no impact on the population.“, defends Frode Ødegaard who ensures that what really threatens insects is the degradation of their habitat, not the removal of a single individual.