A New Bee Species with an Unusually Long Tongue
May. 10 de 2012
By: Elizabeth Vera Martínez, UNIMEDIOS
Scientists estimate that there are around 20,000 species of bees in the world, and approximately 5,000 are found in the Neotropic, in other words, in Latin America, according to Carlos Sarmiento Monroy, an entomologist at the Institute for Natural Sciences of the Universidad Nacional (National University).
The complete inventories carried out by the Bee Research Laboratory of the National University (Laboratorio de Investigaciones en Abejas de la UN –Labun), led by Professor Guiomar Nates, contain information on the five families of these insects present in Colombia (Colletidae, Andrenidae, Halictidae, Megachilidae and Apidae), around 60% of the genuses and nearly 25% of the species.
Euglossa natesi n. sp. is one of the orchid bees, so named because of its pollinating action and special relationship with these flowers. According to Rudolfo Ospina, professor at the Biology Department of the UN and who first described this new variety, "the males are attracted by certain species and not only look for honey and pollen but also aromatic substances".
With long tongues
All of the bees of the genus Euglossa, which in Germany are known as Jewel Bees because of their bright blue, green, brass and gold colors, have very long tongues. This organ can be even longer than their bodies, but even so the tongue of the Euglossa natesi, named in honor of Professor Guiomar Nates for her contribution to the study of bees, is unusually large.
"This insect is different, because it has the longest tongue found until now, which is more than twice the length of its body", says Professor Ospina. He added that this characteristic enables it to gain access to sources of nectar that other bees cannot reach while at the same time pollinating other plants besides orchids.
Euglossa natesi looks for oleaginous substances that it can use to attract a mate. It impregnates its feet with aromatic oils that it stores in its rear tibias, and using a kind of spray in its middle feet, deploys fragrances that it uses to compete and seduce the females. Every male has its own combination of aromas.
The orchid bees are abundant in the rainforests of the lower altitudes of the Neotropical region, "although the possibility that some species also live in dry and open habitats cannot be ruled out", says Ospina.
There is still disagreement among scientists regarding the subgenus E. natesi, because on the one hand its morphology is similar to that of Glossurella, such as the absence of hoods on the sternum, while on the other hand it resembles Glossura, in the form of the posterior tibia, the length of the tongue, the size of the body and the tuft of hair that the males have at the tip of their genitals. This contradiction makes them unique among the members of these two subgenuses.
This new bee was found in 2005 in the Río Ñambi Private Natural Reserve in the Department of Nariño, in the municipality of Barbacoas, by student Víctor Solarte, of the Labun, along with Alejandro Parra and Santiago Ramírez, who are carrying out their postdoctoral studies abroad. To trap them in the forest, they used bait that imitated the aromas of the orchids.
The species has a limited distribution and is endemic to the biogeographical region of the Chocó, "which demonstrates the potential biodiversity of this region", says the professor.
The foothills of Nariño where this new species lives is one of the worlds rainiest places, and due to its highly sloped terrain and its vegetation, the bee communities frequently move between relatively close by areas.
This "exchange" of species among neighboring ecosystems is known as "beta diversity or differentiation of the diversity between areas", and complements the concept of alpha diversity, which is based simply on the number of species and their local abundance. In this regard, the foothills of the Pacific and particularly the Ñambi region demonstrate a high level of beta diversity compared to other regions, "as shown by the results obtained with the orchid bee community", according to the expert.
He adds that these insects tend to exploit two types of flowers: those that are available throughout the year and, depending on the season, those from plants with defined flowering periods. For example, some species flower during one month a year, whereas others flower during as many as 10 months.
This strategy of exploiting resources, along with the mobility of the bee communities along the attitudinal gradient (progressive transformation in the vegetation, soil and fauna of a slope) "shows that the forests of the biogeographical Chocó, far from being homogenous, are systems that effectively respond to environmental variations", says Professor Ospina. "Therefore, they must be understood in their variability in order to implement effective measures for protection or recovery of one of the planet's most diverse areas."
The Labun, recognized in the scientific world for its bee collection, has the privilege of conserving the holotype, in other words, the only example that serves as a point of reference for the description and comparison of new species. However, some examples of this species (paratypes) have been sent to other collections.