Effect of Citrus floral extracts on the foraging behavior of the stingless bee Scaptotrigona pectoralis (Dalla Torre)

• Published in: Revista brasileira de entomologia Vol. 56; no. 1; pp. 76 - 80
• Main Authors: Grajales-Conesa, J, Ramirez, V M, Cruz-Lopez, L, Guillen, D S
• Format: Journal Article
• Language: Portuguese
• Published: 01.03.2012
• Subjects: Apis mellifera; Citrus; Farnesol; Flowers; Food sources; Foraging behavior; Fragrances; Habitat; Limonene; Linalool; n-Hexane; Orchards; Pesticides; Pollinators; Scaptotrigona; Workers
• ISSN: 0085-5626

Stingless bees have an important role as pollinators of many wild and cultivated plant species in tropical regions. Little is known, however, about the interaction between floral fragrances and the foraging behavior of meliponine species. Thus we investigated the chemical composition of the extracts of citric (lemon and orange) flowers and their effects on the foraging behavior of the stingless bee Scaptotrigona pectoralis. We found that each type of flower has its own specific blend of major compounds: limonene (62.9%) for lemon flowers, and farnesol (26.5%), (E)-nerolidol (20.8%), and linalool (12.7%) for orange flowers. In the foraging experiments the S. pectoralis workers were able to use the flower extracts to orient to the food source, overlooking plates baited with hexane only. However, orange flower extracts were seemingly more attractive to these worker bees, maybe because of the particular blend present in it. Our results reveal that these fragrances are very attractive to S. pectoralis, so we can infer that within citric orchards they could be important visitors in the study area; however habitat destruction, overuse of pesticides and the competitive override by managed honeybees might have put at risk their populations and thus the ecological services they provide to us.Original Abstract: As abelhas sem ferrao tem um papel importante na polinizacao de muitas especies de plantas nativas e plantas cultivadas em regioes tropicais. Pouco se sabe, no entanto, sobre a interacao entre as fragrancias florais e comportamento de forrageamento de especies de meliponineos. Assim, investigou-se a composicao quimica dos extratos de citricos florais (limao e laranja) e seus efeitos sobre o comportamento de forrageamento da abelha sem ferrao Scaptotrigona pectoralis. Nos descobrimos que cada tipo de flor tem a sua propria composicao especifica de mistura de compostos: limoneno (62,9%), e famesol (26,5%) para flores de limao, (E)-nerolidol (20,8%), e linalol (12,7%) para flores de laranja. Nos experimentos de forrageamento, as operarias de S. pectoralis foram capazes de utilizar os extratos de flores para se orientarem ate a fonte de alimento, nao sendo atrapalhadas por placas com iscas apenas de hexano. No entanto, os extratos de flores de laranja foram aparentemente mais atraentes para essas abelhas operarias, talvez por causa da mistura particular do extrato. Nossos resultados revelam que essas fragrancias sao muito atraentes para S. pectoralis, assim pode-se inferir que dentro de pomares citricos poderiam ser visitantes importantes na area de estudo; no entanto a destruicao do habitat, o uso excessivo de pesticidas e a substituicao competitiva por abelhas Apis poderia por em risco suas populacoes e, assim, os servicos ecologicos que prestam para nos.