Scaptotrigona postica

Scaptotrigona postica
Scaptotrigona postica
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Apidae
Genus:	Scaptotrigona
Species:	S. postica
Binomial name
Scaptotrigona postica (Latreille, 1807)
S. postica distribution

Scaptotrigona postica (also known locally in Brazil as mandaguari) is a species of

Scaptotrigona postica are medium-sized, averaging 1.2 cm in length and cross-sectional area of 5.3 mm². They appear dark gray with some sections of dark yellow in color, with black eyes.[2]

Queens are the largest bees in the nest, averaging 38–50 mg, and are identifiable by their swollen abdomens.

Workers are the smallest bees in the nest, weighing between 15–22 mg and are black in color. They assume different roles in the nest based on their age.[5]^[6]

0 days old = produce wax

16–20 days old = provision cell broods

21–35 days old = colony cleaning

21–45 days old = nectar reception and dehydration

31–40 days old = colony defense

26–60 days old = foraging

Drones are almost identical in size as the workers, but weigh slightly more.^[4] They weigh on average 17–30 mg and are black in color. The drones are the male bees hatched from unfertilized eggs. Their role is to mate with the queen to produce female bees. They do not participate in many other activities.^[5]

Nest

Scaptotrigona postica nest in partially hollow sections of trees in the tropical rain forests of Brazil. The nests range from 3–7 meters above ground with a canopy overhead, approximately 15–20 meters above the nest.^[2] One of the common trees nested by S. postica is the Caryocar brasiliense, also known as the cerrado-tree.^[7]

The nest consists of inner

Each nest contains one colony of S. postica. It carries between 2,000–50,000 individuals, averaging 10,000 bees per colony.^[citation needed]

Distribution and habitat

Scaptotrigona postica is found in the southern, central-western and northern regions of Brazil as the dense tropical rain forests provide ideal nesting locations.^[8] These bees maintain an average nest temperature of 32˚C,^[9] which is a few degrees above the average temperature of the Brazilian rain forests (27˚C). With the addition of an insulating layer, the nest temperature can be easily maintained in this environment. S. postica have also been found in Peru but are much more common in Brazil.^[9]

Colony cycle

Initiation

Worker bee swarming initiates a new colony. These bees occasionally invade the nests of nearby bee species. New nests house up to three virgin queens during initiation. The queen arrives at the new colony within 5 days of the beginning of swarming. While there can be three virgin queens to begin a nest, the workers will kill two of them to leave a single, reproductive queen for the nest.^[3][10]

Growth

The growth of the colony depends on nest productivity. During colonization, productivity is low, restricting population growth. As productivity increases, colonies begin male production, increasing overall population growth until reaching an average size of 10,000 individuals. This growth is season dependent. During the rainy season, colony growth rate raises due to increased resource availability.^[11]

Lifespan

The average lifespan of S. postica workers ranges from 30–40 days. They have a low mortality rate during the initial stages of life because they do not leave the nest. Death of individuals becomes significant after approximately 15 days and continues increasing until about 40 days. Unlike the worker bees, the queen bees can live for multiple years, averaging a longer lifespan.^[12]

Male Production

Male production depends on the season. Production of males is restricted during food shortages, creating short periods of male production with longer periods of female production. Males are produced by unfertilized eggs laid by the workers.^[13]

Communication

Scaptotrigona postica communicate to recognize nest-mates, identify the caste of any individual bee, locate food, and signal danger.

Cuticular hydrocarbons

Cuticular

A main predator of S. postica is the sphecid wasp Trachypus boharti. This wasp is also found in Brazil and exclusively preys on the males of S. postica. The wasps hover near the entrance of the nest in groups averaging to 11 wasps in a group. These wasps capture up to 50 S. postica drones per day close to the entrance of the nest.^[28] The drones hover at the entrance of the colony waiting for emerging female queens to mate with. It captures the individual and preserves it using a secretion from the wasp's post-pharyngeal glands.^[29] Fortunately for S. postica, these predation attempts are generally unsuccessful as T. boharti only captures a male drone 7% of the time. Most of these failed attempts are due to conflict with other wasps (interfering with the flight path, collisions, and competition).^[28] Furthermore, if a wasp captures a different individual of the colony (mainly all female bees), it immediately releases the individual with no harm done. While the T. boharti only predate the drones of S. postica, they do not seek specifically those individuals, rather they are attracted to all S. postica and select their prey after capture.^[28]

Defense Methods

The defense for S. postica nest is to have on average 8 workers guarding the front of the nest at all times. Sometimes the guards are sitting nearby and, at others, they fly back and forth across the entrance.

Scaptotrigona postica are pollinators for plants in the Brazilian rain forests. S. postica exploit a smaller number of the many plant species. The main flower type visited by this species on the campus of São Paulo University was that of Eucalyptus, making up over 45% of the pollen collected by the workers. Some secondary sources for pollen and honey were Mimosa daleoides, Lithraea molleoides, Leucaena leucocephala, and Piptadenia gonacantha.^[27]

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