RESUMO
Cuticular wax, abdominal and cephalic extracts of foraging workers and males of Nannotrigona testaceicornis and Plebeia droryana, from the "Aretuzina" farm in São Simão, SP, Brazil, were analyzed by GC-MS. The principal constituents were hydrocarbons, terpenes, aldehydes, esters, steroids, alcohols, and fatty acids. Interspecific differences for both cuticular wax and cephalic extracts were found. The composition of cuticular wax and cephalic extracts was similar at the intraspecific level, with minor component differences between males and workers. Abdominal extracts differentiated sexes (male and worker) at the intraspecific and interspecific levels. The main chemical components in abdominal extracts of N. testaceicornis workers and males were geranylgeranyl acetate and (Z)-9-nonacosene, respectively. The principal components of abdominal extracts from P. droryana workers and males were tetradecanal and unsaturated fatty acids (linoleic and linolenic acids), respectively. A secondary alcohol, (S)-2-nonanol, was detected in Plebeia droryana males only, but not in workers. Preliminary field experiments showed that (S)-(+)-2-heptanol and (S)-(+)-2-heptanol/(S)-(+)-2-nonanol (1:1) attracted workers of P. droryana, N. testaceicornis,and Frieseomelitta silvestrii. However, males did not respond suggesting that these compounds do not function as alarm or recruitment pheromones. In addition, racemic mixtures were inactive.
Assuntos
Abelhas/química , Aldeídos/química , Animais , Álcoois Graxos/química , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Ácido Linoleico/química , Ácidos Linolênicos/química , Masculino , Feromônios/análise , Fatores Sexuais , Estereoisomerismo , Ceras/químicaRESUMO
Some groups of bees collect oil from flowers and use this product to feed the larvae and to line the nestsand brood cells, as is the case for bees of the Neotropical genus Tetrapedia (Tetrapediini, Apidae). They aresolitary and construct their nests on pre-existing cavities in wood. Aiming to bring a better understandingof the oil collecting structures of Neotropical oil bees, in this study we examined the foreleg morphologyof female of Tetrapedia diversipes Klug, showing on SEM the adaptations of forebasitarsus for collectingoil from flowers. The metasoma of female bees was measured and dissected using stereomicroscope andthe size and shape of the Dufours gland were estimated. T. diversipes hold a curved comb on the basitarsusof the front leg to collect oil and a mixture of slender and branched hairs on the scopa of the hind leg totransport it. These structures are very similar on other examined Tetrapedia species. The Dufours glandof T. diversipes is reduced, occupying about 2.2% of the metasoma. Further investigation of the chemicalcomposition of the Dufours gland secretion, of the cell lining and of the collected floral oil might clarifythe role of these components on T. diversipes life.