Vera Lúcia Imperatriz Fonseca

Espécies arbóreas utilizadas para nidificação por abelhas sem ferrão na caatinga (Seridó, PB; João Câmara, RN)

In Rio Grande do Norte, a caatinga region of North-eastern Brazil, the nesting opportunities that trees offer to stingless bees (Meliponinae) were studied. Samples consisted mostly of tree trunks, which were kept by Meliponinae beekeepers. Nearly 13 per cent of observed nests were in living trees in the field. Seven species of stingless bees, totalling 227 nests, were encountered in 12 tree species. More than 75.0% of stingless bees were found in two tree species being Caesalpinia pyramidalis (Caesalpiniaceae, 41.9%) and Commiphora leptophloeos (Burseraceae, 33.9%). Furthermore, all bee species nidify in C. pyramidalis. A great part of the nests in trunks were of Melipona subnitida, (N = 130) of which 50.0% was found in C. leptophloeos and 22.3% in C. pyramidalis. M. asilvai was predominantly found in C. pyramidalis (92.3%, N = 39). Besides this survey was mainly directed to bee species with beekeping importance, data shows the huge relevance of these two plant species for nesting by stingless bees in the caatinga.

Seasonal availability of floral resources and ambient temperature shape stingless bee foraging behavior (Scaptotrigona aff. depilis)

The foraging success of a bee species is related to a combination of climatic factors and resource availability. Here, we analyzed how food storage by the stingless bee Scaptotrigona aff. depilis relates to the seasonal variation in floral resources availability in a tropical environment with two well-defined seasons. We found a positive relationship between the amount of food stored and resource availability, suggesting that colonies intensify food collection in the season with higher food availability (rainy season). This ensures the perennial state of stingless bee colonies during the dry season (food scarcity and lower ambient temperatures). Bees collected pollen from at least 60 plant species, but food pots were dominated by just nine plants. Additionally, S. aff depilis attempted to unevenly use the plant species for food storage in the rainy season, which indicates that the colonies maximize their food intake as soon as resources are available.

Selective preying of the sphecid wasp Trachypus boharti on the meliponine bee Scaptotrigona postica: potential involvement of caste-specific cuticular hydrocarbons

The specialist digger wasp Trachypus boharti Rubio‐Espina preys exclusively on males of the stingless bee Scaptotrigona postica Latreille 1807, although the hunting attacks involve both male and worker bees of S. postica and members of its own species. To understand the mechanism of prey selection, the cuticular hydrocarbon patterns of workers and males of S. postica are analyzed in detail, and the mandibular secretion of males is examined. The cuticular profiles of males and workers are distinctively different. The major group of cuticular compounds, heptacosene isomers, is twice as abundant in workers as in males. There is no clear distinction between worker and male mandibular secretions. Such a distinct and straightforward caste‐specific difference in cuticular hydrocarbons could function as a recognition cue by which T. boharti distinguishes between workers and males of S. postica.

Copepods of the genus Oithona from Cananéia region (Lat. 25º07'S, Long. 47º56' W)

Some ecological aspects of two congeneric species of Cyclopoid copepods, Oithona ovalis and O. oligohalina have been studied for the first time in the estuarine region of Cananeia. The spatial distribution and seasonal variation of both species of Oithona are studied in relation to salinity, temperature and dissolved, oxygen. The results obtained are compared to previous work done in the area and to similar studies undertaken elsewhere.

The naupliar development of Oithona oligohalina, Fonseca & Björnberg, 1976

The naupliar stages of Oithona oligohalina are described and compared with those of O. ovalis.