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Plebeia remota
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Suborder:	Apocrita
Superfamily:	Apoidea
Family:	Apidae
Subfamily:	Apinae
Tribe:	Meliponini
Genus:	Plebeia
Species:	P. remota
Binomial name
Plebeia remota (Holmberg, 1903)

Plebeia remota is a species of stingless bee that are in the family Apidae and tribe Meliponini. They are normally found in a few states in southern Brazil and there nest can be found in tree cavities. It diet consists of nectar and pollen. Many studies have been done analyzing the changes that occur in the colony during reproductive diapause.

Taxonomy and phylogeny

Plebeia remota is a member of the order Hymenoptera which is the insect order comprised of bees, wasps and ants. Within Hymenoptera, they belong to the family Apidae. This bee belong in the tribe Meliponini in which the greatest number of them reside in the Neotropics where there are about 300 species known. Within the genus Plebeia, there are about 30 species described. Like the other species in Meliponini, P. remota is a stingless bee.

Description and Identification

Plebeia remota is a small bee, roughly about 3-6 mm in length. They show characteristics of bees in the genus Plebeia which include whitish or yellow stripes on the face and thorax. Like other species in Meliponini, its body is trigoniform, sparsely hairy and wing venation is reduced.

The nests of P. remota normally consists of a small, propolis entrance that is only large as the size of the head of the worker bee, a pile of 8-10 horizontal combs away from the entrance, honey pots and pollen pots that are located close to the combs and entrance respectively and sites for resins storage and waste materials. The waste materials get disposed of during the daytime.

Distribution and habitat

The distribution range of Plebeia remota is not very large compared to some other bee species. They are normally found distributed in southern Brazil in the states of Minas Gerais, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul.The nests of P. remota are usually found in tree cavities however finding them in nature is difficult since the size of the entrance is very small. The size of the nest can range up to 5000 individuals.

Colony cycle

The majority of the time P. remota produces a few young virgin queens, also known as gynes, a year. As such the number of new colonies form is few. The gynes that live after emerging from their cells will have the chance of forming their own swarm and leave the nest. Another equally viable option is that the gynes would just take over the nest once the current queen dies. The gynes that form their own colonies do not go far from where they were born. Thus there tends to be clusters of nest where the individuals in that area would be related to each other.

Behavior

Hygienic behavior

Compared with other species of stingless bee such as Melipona quadrifasciata and Tetragonisca angustula, P. remota show incredibly efficient hygienic behavior in response to dead brood. Within a 24 hour period, P. remota remove an average of 69.6% of dead brood and by 48 hours 96.4% of dead brood are removed. This is more efficient than M. quadrifasciata and T. angustula which in 72 hours only removed 1% and 30% respectively. The P.remota’s efficient hygienic behavior shows that they have a way to resist diseases.

Division of Labor

In P. remota, the division of labor is based on the age of the worker. There are 7 different tasks that have been observed in the nest of P. remota and each of them occur at different times in the workers life. The first task that workers perform usually involves either using cerumen to build the bars between combs and walls or building and maintaining the storage pots and the connecting cerumen bar. This occurs a few days after emerging. The second tasks that worker do involves working on the old combs, helping the young bees to emerge, feeding them and then gnawing off the remains of the cell. This happens when they are between the ages of 6 and 30 days. The third task is building the cells which is limited to bees that are 12-24 days old. This is also the task where the fewest number of bees participate. The fourth task workers do is called dehydration. This is just collecting the nectar from the pots. This is done by workers that are older than 18 days or by the males. The fifth task is receiving nectar from foragers and is done by worker that are older than 24 days. The sixth task is foraging and it is normally done in the final stage of the workers life which starts at day 30. The seventh task is involve tasks around the royal chamber for the gynes which involve reconstruction and maintenance and are done by workers between the ages of 23 and 85 days. Task 1 is done by 94% of the workers, task 2 is done by 21% of the workers, task 3 is done by 12% of the bees, task 4 is done by 69%, task 5 is done by 60%, task 6 is done by 46% and task 7 is done by 27% of the workers.

Mating Behavior

Unlike bees in Apini where the queen would make with multiple males, queens in P. remota only mate with one male. The males will crowd around the entrance to the colony since this will increase the male’s chances of mating with the virgin queen. The male will attempt to mate with the queen as she tries to leave the nest. The male that mated with the queen will then leave a mating plug to deter further chances of mating.

Changes during reproductive diapause

In P. remota, they undergo reproductive diapause during the autumn and winter in Brazil in which there is reduced activity in brood production. During reproductive diapause many changes happen in the colony. One change is that construction of cells and the allocation of food for the cells stop. Another change that occurs is that the foraging patterns of the bees change. During diapause foraging will normally occur in the middle of the day whereas during the reproductive phase foraging was relatively constant throughout the entire day. There are also changes that occur in workers during reproductive diapause. Not only are worker born right before or right after diapause have longer lives, but the age when they start foraging also changes from 43 to 90 days during the reproductive phase, to 42 to 107 during diapause.

Kin Selection

Genetic relatedness

In P. remota, the relatedness of the colony is typical of bee species that only mate once. Queens are 50% related to workers, workers are 75% related to each other, males laid by the queen is 100% related to the queen and 25% related to the workers which is the typical ratio for haplodiploidy. As such, there is queen-worker conflict over the sex ratio. The workers will attempt to lay their own eggs instead because the males born from their eggs will be more related to the workers than the unfertilized egg laid by queen. In the end the queen will usually win the conflict because majority of males in the colony are from the queen. This is mainly because when the queen approaches a worker, either the worker will move away or lay a trophic egg that either the queen or another worker will eat.

Life History and survivorship curves

Workers

In one study that examined 37 brood combs from five colonies of P. remota, it was shown that 73.40% of the individuals were workers. Workers are produced throughout the entire year and perform many of the functions needed to grow and maintain the nest. From a few days after they are born to when they die, they are always doing something for the hive, whether if it is building the nest near the start of their lives to forging near the end of their lives.

Queens

In one study done it was shown that a typical nest would rear between 1-5 gynes during an observation period that varied between 6 and 18 months. However it was also noted that on occasion P. remota may produce a high number of gynes that can even reach 46. Another thing to note about the gynes is that they can produced in the same cells that give rise to the worker class. . The only difference between the queen and the workers is that queens are generally bigger, however this is not always the case since it has been documented that queens can be the same size as the workers. The same study also showed that there is no correlation between the size of the queen and whether they are accepted or have a successful mating. Queens emerge always attractive, meaning that they cause changes in the intranidal behavior of the workers. Normally after gynes are produced, a majority of them are killed by the workers in time. The ones that survive can be kept alive in cerumen chambers protected by a barrier of wax called the royal camber. It is those survivors who will go on and form new colonies.

Interaction with other species

Diet

The diet of P. remota normally consists pollen and nectar. Depending on the time of year and various climatic factors, the amount of pollen and nectar collected can change.