Enfleurage, lipid recycling and the origin of perfume collection in orchid bees

Abstract

Enfleurage, the extraction of elusive floral scents with the help of a lipophilic carrier (grease), is widely used in the perfume industry. Male neotropical orchid bees (Euglossini), which accumulate exogenous fragrances as pheromone analogues, use a similar technique. To collect fragrances, the bees apply large amounts of straight-chain lipids to odoriferous surfaces from their cephalic labial glands, which dissolve the volatiles, and the mixture is then transferred to voluminous hind-leg pockets. Here, we show that males do in fact operate a lipid conveyor belt to accumulate and concentrate their perfume. From the hind-leg pockets of caged male Euglossa viridissima, deuterated derivatives of carrier lipids were consecutively sequestered, shuttled back to the labial glands and reused on consecutive bouts of fragrance collection. Such lipid cycling is instrumental in creating complex perfume bouquets. Furthermore, we found that labial glands of male orchid bees are strikingly similar to those of scent-marking male bumblebees in terms of size, form and structure. This, and a prominent overlap in secretory products, led us to propose that perfume collection evolved from scent-marking in ancestral corbiculate bees.

Single mating in orchid bees (Euglossa, Apinae): implications for mate choice and social evolution

“…Given single mating in females, the rarity of observed matings is understandable. Orchid bee males devote much of their life to fragrance collection, a behavior that requires specialized morphological features (Bembé, 2004), an intricate metabolic recycling mechanism (Eltz et al, 2007), and certainly a lot of energy and risk-taking in order to create their perfume. Although the composition of the male's fragrance mixture is broadly species specific, there is substantial individual variation in quantity and complexity of the blends (Eltz et al, 1999;Zimmermann et al, 2006).…”

Herbal medicinal oils in traditional Persian medicine

“…In the latter group, soft, fragrant aerial parts such as flowers, leaves or fleshy fruits were soaked in traditionally prepared almond, sesame and olive oils, among others, and exposed to the sun or an artificial heat source for several days while replacing the spent parts with fresh ones until they are based on the color and aroma of the particular herb (maceration in heated oil) (Heravi, 1765;Avicenna, 1025). This method is comparable to modern-day enfleurage (Eltz et al, 2007). However, in the enfleurage process, animal fat was used.…”

Chemical niche differentiation among sympatric species of orchid bees

“…For reference, we also extracted individual heads of all species to gain information on compounds produced by male cephalic labial glands. Labial gland lipids are spat on fragrant surfaces by the males and serve as a carrier during the process of fragrance collection (Eltz et al 2007). As both lipids and exogenous volatiles are present in hind legs, we used information on head extracts to identify exogenous compounds.…”

“…Males of all species of orchid bees possess voluminous pockets in their hind legs, which they use for the collection and accumulation of exogenous volatiles, mostly derived from flowers, fragrant plant exudates, decaying vegetative matter, or feces (Vogel 1966, Whitten et al 1993, Eltz et al 2007). This unique behavior has led to the evolution of one of the most intriguing pollination syndromes.…”