Bombus transversalis
From Wikipedia, the free encyclopedia
| Bombus transversalis | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Apidae |
| Genus: | Bombus |
| Subgenus: | Thoracobombus |
| Species: | B. transversalis |
| Binomial name | |
| Bombus transversalis (Olivier, 1789) | |
Bombus transversalis is a bumblebee specifically native to the Amazon Basin.[2][3][4] It is most notable for its surface-level colonies which are built by the workers on the rainforest floor. Unlike its relatives, B. transversalis is able to thrive in a humid climate and fend off a wide range of predators because of its resilient nests. While there is great deal of information pertaining to their nests and foraging abilities, there is much more to be learned about relationships within the colony and life cycle of the bee.
Bombus transversalis is in the order Hymenoptera, which consists of bees, ants, wasps, and sawflies. It is in the family Apidae and in the genus Bombus. Most Bombus live in temperate climates and build their nests underground from abandoned tunnels.[3] Bombus transversalis has adapted to tropical climates and builds its nests on ground surface. It is classified under the subgenus Thoracobombus.[5] An example of a related species would be Bombus pauloensis.[6] However, Bombus transversalis is the only one of this subgenus known to build their own nests out of leaves and twigs.[4]
Distribution and habitat
Bombus transversalis is primarily found in the lowland tropical rain forests of the Amazon Basin.[2][3] They can be found throughout much of South America, including parts of Peru, Ecuador and Brazil.[5] They are generally seen as the bumblebee colonizers of Neotropical rain forests.[7] As such, they are adapted to surviving in a humid climate with heavy rainfall throughout the year. Their nests are found in soil which is not flooded.[4] They are generally built next to the roots of trees or among shrubs for support.[4]
Colony cycle
The Bombus transversalis colony cycle is based on the season of the year.[4] Colonies are formed during the wet season. During this time the colony is continually developing. When the dry season comes, they become reproductively active for a few months.[4] However, once the wet season comes around again, the life of the colony comes to an end and a new colony is eventually formed when the queen finds a suitable site.
Foraging
Alerting
While the Bombus transversalis is unique in its distribution, nesting, and foraging, it is still a social bee. It has been shown to have similar behavior to that of the Bombus terrestris, a well-studied bumblebee.[5] It was thence shown that although the two bees are distantly related, the Bombus transversalis still shows behavior of alerting its colony about food sources leading to increased activity in and out of the nest.[5]
Trails
It has been observed that B. transversalis uses walking trails similar to those of ants.[3] These trails extend out from the nest in opposite directions and are patrolled by at least 20 workers who collect materials and forage along the trails.[3] Workers on the trail cut leaves and debris into tiny pieces and push them to the side as they create trails. It has been observed that workers do this process in pairs, as they push debris to their fellow worker behind them.[4] As such, lines of five or more bees have been observed walking along trails nearby their nest. One purpose of these trails is to forage. This is unique because most bees forage via flight.[3]
Nest
Structure
The structure of the Bombus transversalis nest is very complex. It is cone-like in shape with two separate combs.[7] Oftentimes it is built off of existing nests, so there are many unused cells. The brood comb is built at the top and is surrounded by large honey silos. Some are filled with honey, but most are empty, as there is an abundant amount of storage.[3] There is one single entrance to the colony.[7] It is open and uncamouflaged but is usually guarded by 2–5 worker bees.[7] Entirety of the colony is covered in a heap of twigs, leaves, and roots which serve as a canopy. This heap is very dense and waterproof. It also provides an air space which helps the bees manage the temperature and humidity of the nest.[4]
Construction
Another purpose of the trails created by Bombus transversalis is to build up the structure of the nest. Using the twigs, leaves, and litter on the forest floor, worker bees cut up the debris into fragments and then bring these pieces back to the nest to build onto the canopy. As long as the trails are continuously being used, workers will continue to clear the trails even if leaves fall from the trees above. As such, the trails which have been observed of the Bombus transversalis serve a dual purpose in both foraging and nest construction.[4]
Selection
A queen Bombus transversalis must choose its nesting site very carefully if she hopes to have a successful colony. First, she must choose an area which has ideal soil and will not flood when it rains a lot.[4] Secondly, she must find adequate structural support for her nest. Oftentimes, this will take form in the roots of a large tree or among saplings and shrubs. This will give the workers a base to build the canopy for the colony and provide adequate shade for the nest.[7]