Trigona fulviventris, known by the common names "culo-de-vaca," "culo-de-señora," "mu'ul-kab," "culo-de-buey," and "culo-de-vieja," is a species of stingless bee found in neotropical regions of Central and South America. It is one of the largest and most widespread bees of its genus. They exhibit complex foraging behaviors by integrating spatio-temporal learning and flower scents. T. fulviventris has traditionally been observed to abstain from aggressive behavior with other species; however, more recent analyses have shown that T. fulviventris emit pheromones that act as attack signals particularly when related individuals are captured by predators.

Trigona fulviventris was first described by Félix Édouard Guérin-Méneville in 1845. It is a member of the order Hymenoptera, which includes ants, bees, wasps, and sawflies and part of the family Apidae, which includes other bees such as bumble bees, honey bees, and orchid bees. It is further categorized in the genus Trigona, a genus of stingless bees. Two subspecies of T. fulviventris have been identified: T. f. fulviventris and T. f. guianae. These subspecies are distinguished by coloration; morphological studies have shown that the subspecies cannot be easily separated by strictly morphological analyses.

Trigona fulviventris individuals are morphologically characterized by the expression of two projections, called tubercles on their labra as well as the presence of four mandibular teeth. The two identified subspecies of T. fulviventris, T. f. fulviventris and T. f. guianae, can be distinguished by differences in metasomal coloration. T. f. fulviventris metasoma are rust-colored with some differences in tone between individuals, while T. f. guianae metasoma and the rest of the body are black, sometimes expressing some reddish tones. T. fulviventris individuals are among the largest of their genus, ranging in size from 5 to 6.5 millimeters in length. Diet Trigona fulviventris feeds mostly on pollen and nectar. Known species of plant from which T. fulviventris feeds are Passiflora vitifolia, Pavonia dasypetala, Heliconia imbricata, Quassia amara, Dioclea, Lantana camara, Tabebuia, Asystasia, Insertia, Psychotria, Stromanthe, Justicia aurea, Heliconia tortuosa, Hibiscus rosa-sinensis, Impatiens walleriana, and Fuchsia. However, they have also been observed to forage opportunistically on fungi, dead animals, flesh, and fecal matter as well. Nests

Trigona fulviventris is one of the most widely distributed bees of the genus Trigona and is found in Mexico, Belize, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, and the Panama Canal Zone. It is more commonly found at low- and mid-altitudes and has been observed to withstand a wide range of humidities. Habitats in which T. fulviventris colonies make their homes include both tropical dry and tropical wet forests.

New T. fulviventris colonies are established in the spring every year when one or more workers from a previous colony leave their nest and begin scouting divots in tree trunks for a new nest location. These bees have been shown to mark these sites with pheromones, often leaving odor trails to lead to desirable nest locations. However, these pheromones can also attract rival T. fulviventris colonies, which can lead to aggressive encounters between the attracted workers and the new nest-initiation workers (further described in Nest Initiation Aggression below). Once it is determined which workers will inhabit the new area, gynes (reproductive females) will mate with a swarm of males mid-flight and enter the new nest to initiate a new colony.

Foraging Defense and aggression Trigona fulviventris individuals have been observed to abstain from engaging in aggressive behaviors with individuals of other species, particularly larger species like humans. However, T. fulviventris engages in aggressive behavior with smaller arthropods as well as other T. fulviventris individuals, particularly those of other colonies, especially during nest initiation. Nestmate recognition Trigona fulviventris individuals are capable of distinguishing nestmates from non-nestmates through recognition of a range of compounds. These compounds include hydrocarbons and fatty acids that are present in T. fulviventris wax as well as locally available floral oils that are present in plant material used to construct nests. These odor cues are important to judging which individuals are nestmates and which are not, which is necessary in determining which individuals to engage in aggressive encounters with. The amount of time that passes between the first encounter of two bees and the start of aggression between them, called mean latency, is negatively correlated with the occurrence of aggression. In other words, the longer it takes two bees to initiate aggressive behaviors, the less likely it will be that there will be aggression between them. This relationship could be a result of variations in the magnitudes of the differences in olfactory signals two bees put out. For instance, if one T. fulviventris bee has only a slightly different signal than another bee, it will take longer to analyze this difference and engage in an aggressive behavior. In contrast, a large difference in signal is more likely to be noticed immediately and aggressive behaviors can occur more quickly, decreasing the mean latency. Stinging Trigona fulviventris, like other Trigona bees, does not display stinging behavior. Some bees in the genus Trigona have been shown to harbor vestigial stinging accessories; these vestigial structures are largely absent in T. fulviventris individuals.

The sticky resin used by T. fulviventris workers in building their nests has been prized by Colombian fisherman as an effective means of caulking fishing canoes that have sprung leaks.