Secretions of stingless bees: cephalic secretions of two Frieseomelitta species

Volatile Organic Compounds from Offspring of Stingless Bee Sacrificed in Hygienic Behavior Test

This study shows the profile of volatile organic compounds (VOCs) from pupae and larvae of Melipona quadrifasciata anthidioides Lepeletier subjected to three death induction techniques for hygienic behavior (HB) studies: freezing in liquid nitrogen (LN2), freezing in a freezer (FRZ) and piercing of offspring with an entomological pin (PIN). The VOCs from larvae and pupae were obtained through headspace solid-phase microextraction and characterized using gas chromatography coupled to mass spectrometry. In addition, an HB test was performed on the colonies. The main classes of VOCs were hydrocarbons, terpenes and alcohols. Multivariate analysis was applied and showed that there was a separation in the compound profiles between the different treatments. The HB test in the colonies showed that 24 hours after the application of the techniques, the bees removed more dead larvae in LN2 treatment (83.5 %), while after 48 hours more larvae were removed in the LN2 and FRZ treatments (92.3 %). When compared to pupae removal, larvae removal was significantly faster in LN2.

Chemical Changes Associated with the Invasion of a Melipona scutellaris Colony by Melipona rufiventris Workers

Wax constituents produced by worker bees and the chemistry of the nest batumen (mixture of wax, mud, and floral materials) in a Melipona scutellaris colony changed when it was invaded by Melipona rufiventris workers. Gas chromatography/mass spectrometry analyses showed that after invasion, the M. scutellaris workers of the invaded colony produced waxes with higher relative abundance of triacontanyl acetate and decreased the amounts of n-alkanes and n-9-alkenes. On the other hand, waxes from M. rufiventris workers displayed few changes. The change in the composition of the M. scutellaris waxes chemically differentiates that species from the M. rufiventris invader workers. Comparative analyses of batumens samples from pure and invaded colonies revealed greater amounts of terpenes and phenolic derivatives in the batumen from the invaded colony. This is the first report on the chemical characterization of batumens from stingless bees.

Hexyl decanoate, the first trail pheromone compound identified in a stingless bee, Trigona recursa

Foragers of many species of stingless bees guide their nestmates to food sources by means of scent trails deposited on solid substrates between the food and the nest. The corresponding trail pheromones are generally believed to be produced in the mandibular glands, although definitive experimental proof has never been provided. We tested the trail following behavior of recruits of Trigona recursa in field experiments with artificial scent trails branching off from natural scent trails of this stingless bee. First-time recruits (newcomers) did not follow these trails when they were laid with pure solvent or mandibular gland extract. However, they did follow trails made with labial gland extract. Chemical analyses of labial gland secretions revealed that hexyl decanoate was the dominant component (72.4 +/- 1.9% of all volatiles). Newcomers were significantly attracted to artificial trails made with synthetic hexyl decanoate, demonstrating its key function in eliciting scent-following behavior. According to our experiments with T. recursa, the trail pheromone is produced in the labial glands and not in the mandibular glands. Hexyl decanoate is the first component of a trail pheromone identified and proved to be behaviorally active in stingless bees.

Electroantennography in the study of two stingless bee species (Hymenoptera: meliponini)

The first recorded electroantennographic preliminary studies on stingless bees have been performed using two species of Frieseomelitta from Brazil. Experiments with F. silvestrii and F. varia showed that antennae respond to hexane extracts of heads and abdomens of both species and posterior tibia of F. silvestrii (which carry plant resin), as well as to the pure compounds 2-heptanol and 2-nonanol, which occur in the mandibular glands of both species, and to the terpenes alpha-cubebene, humulene, and beta-caryophyllene found on their tibia and in the cerumen of their nests.

The propolis of stingless bees: terpenes from the tibia of three Frieseomelitta species

The posterior tibia of foraging workers of three species of Frieseomelitta (Hymenoptera: Meliponinae) stingless bees have been shown to carry complex mixtures of plant-derived mono-, sesqui-, di- and tri-terpenes. These subtances were not found on the fore- or mid-legs, nor on other parts of the hind legs. F. silvestrii and F. silvestrii languida, when collecting, appear to exploit different plants for their resin even when housed in the same area. F. varia were found to be not collecting resin at the time of the initial sampling and were therefore sampled later. Mature foragers carry the resin. In the samples studied here, particularly prominent were the monoterpene alpha-pinene, the sesquiterpenes beta-caryophyllene, alpha-cubebene, alpha- and gamma-muurolene, gamma-cadinene, germacrene-D, and elemol and the diterpenes manool and totarol The collected material is used for the resin placed around the entrance to their nests and is also mixed with wax, to produce the cerum used for the structures in the nest.