Márcia Rêgo

Aspectos da biologia de nidificação de Centris flavifrons (Friese) (Hymenoptera: Apidae, Centridini), um dos principais polinizadores do murici (Byrsonima crassifolia L. Kunth, Malpighiaceae), no Maranhão

The Centridini has almost 176 species distributed mainly in the tropic regions of America. Although they are considered key pollinators in the maintenance of many vegetal species, data about their bionomics are restrict. Nesting activity is known for 11 species, out of the 21 that are considered pollinators of murici, Byrsonima crassifolia L. Kunth, a valuable biomonitoring specie. A study of the nesting biology of Centris flavifrons (Friese) was conducted in the state of Maranhão, Brazil, during the active period of the adults (May through December). Nests were aggregated. The females excavated their nests on flat surfaces of hard soils. Fifteen nests were dug and we only found cells in six of them. The nests architecture consisted of a single unbranched tunnel, with only one cell in the vertical position at the end, which was 25 cm to 50 cm away from the entrance. Nocturnal activity was observed in the nests building. The pollen analysis of the contents of four cells allowed to identify 23 floral species, six of them Malpighiaceae. Six floral species were registered visiting C. flavifrons by the first time: Lecythis lurida (Miers) Mori, Hymenea courbaril L., Myrcea sp., Protium sp., Tetrapterys sp. and Thalisia sp.

Nidificação de Centris (Hemisiella) tarsata Smith (Hymenoptera, Apidae, Centridini) em ninhos-armadilha no Nordeste do Maranhão, Brasil

Nidification of Centris (Hemisiella) tarsata Smith (Hymenoptera, Apidae, Centridini) in trap nests in Northeast Maranhao, Brazil. This work had as objective to obtain ecological data of Centris (Hemisiella) tarsata Smiths nidification in three ecosystems: riparian forest (MC), mesophitic forest (MM) and eucalyptal (EC), using trap nests made by bamboo canes, distributed in differentiated heights: 1,5 m and 5-12 m high. A total of 41 nests were collected: 31 in EC and 10 in MM, the majority in the upper strata and with the largest frequency of nesting occurring in the dry season. The sex ratio was of 1.9:1 (females/ males) in EC and of 1.08:1 in MM. About 22% of nests of the EC and 40% of MM were parasitized by Mesocheira bicolor (Fabricius 1804) (Hymenoptera, Apidae) and Coelioxys sp. (Hymenoptera, Megachilidae). The pollinic analyses showed a higher quantity of pollen grains of Banisteriopsis sp. (Malpighiaceae) and Cassia sp. (Caesalpiniaceae) in EC area and a species of Caesalpiniaceae Kunth. and Banisteriopsis Robinson in MM area.

Community of male Euglossini bees (Hymenoptera: Apidae) in a secondary forest, Alcântara, MA, Brazil

From September, 92 to August, 93 bee sampling was done in a secondary forest near the Pepital River, in Alcântara, MA, in order to study the local Euglossini fauna. Five aromatic compounds were used: eucaliptol, eugenol, methyl salicylate, vanillin, and benzoate. Four hundred sixty-seven male Euglossini bees were captured, distributed in 4 genus and 19 species. Euglossa was the most abundant and with high diversity (302 specimens and 14 species), followed by Eulaema (121; 3), Eufriesea (41; 1), and Exaerete (3; 1). The species which more frequently visited the bait were Euglossa piliventris (141 specimens; 30.19%), Euglossa cingulata (113; 24.21%), Euglossa ignita (45; 9.64%), Eufrieseapulchra (41; 8.78%), and Euglossa gaianii (33; 7.07%) corresponding to 79.88% of the sampling universe. The bees were active throughout the year, however during the rainy season more activity and diversity were observed. The most attractive essence was eucaliptol (44.32% specimens and 84.21% species). In spite of this study having been done in a forest fragment, a secondary vegetation area smaller than other areas studied in Maranhão, it showed a significant diversity rate. This result reinforces the importance of fragments in the conservation of local bee communities.

Fenologia e biologia reprodutiva de duas espécies de Byrsonima Rich. (Malpighiaceae) em área de Cerrado no Nordeste do Brasil

The knowledge of the phenology patterns and of the floral biology, the determination of the role of the vectors of pollen flow, besides the understanding of the reproductive system, are fundamental points for the understanding of the reproductive biology of the species. The pollination ecology, reproductive system, flowering phenology and floral visitors of Byrsonima umbellata Mart. and B. rotunda Griseb. were studied in a Cerrado area, at Urbano Santos municipality, Maranhao State. B. umbellata presented extended flowering period (eight months) and B. rotunda showed brief flowering period (one month). The species had hermaphroditic flowers with diurnal anthesis. B. umbellata is facultatively self-incompatible, showing higher fruit production through cross-pollinators (46.6%), and B. rotunda is mainly self-compatible, with fruit production in all treatments, even through agamospermy (60%), although higher production was achieved in geitonogamy (90%). We observed 42 and 16 species of bees in B. umbellata and B. rotunda flowers, respectively. Centris aenea and C. (Trachina) sp.n. were considered the main pollinators of B. umbellata flowers and C. aenea of B. rotunda. Both Byrsonima species present important ecological function, representing important resources to several species of bees during flowering season deficit in the studied environment.

Espectro polínico de mel de tiúba (Melipona fasciculata Smith, 1854, Hymenoptera, Apidae)

abstRaCt The pollen spectrum of honey of the Melipona fasciculata was analyzed aiming to elucidate the nectariferous resources used by this species. The identification of the visited plants was based upon the analysis of the pollen spectrum of 12 honey samples collected in one meliponarium located in Palmeirândia county, lowland area of Maranhao State, Brazil (02o40’47,6S, 44o52’39,8”W). The quantitative and qualitative analysis of honey samples was conducted in order to determine the pollen type percentages and frequency classes. Forty-five pollen types were found, being Pontederia parviflora Alexander (Pontederiaceae) the most frequent species during period of sampling (38.6%) and considered dominant pollen in October (86%), June (85%), July (76%), August (49%) and September (51%) and accessory pollen in December, January and March. Mimosa caesalpiniifolia Benth (Mimosaceae) was the second most frequent species (22.8%) and was a dominant pollen in November (46%), April (74%) and May (72%).

Abelhas Euglossina (Hymenoptera, Apidae) coletadas em uma monocultura de eucalipto circundada por Cerrado em Urbano Santos, Maranhão, Brasil

Males of Euglossina bees were collected in benzil benzoate, eucaliptol, eugenol, methyl salicylate and vanillin scent baits in an eucalyptus monoculture surrounded by cerrado, located in the municipality of Urbano Santos, Maranhao. The collections were carried out monthly, from April 2001 to April 2002, between 8 a.m. and 4 p.m., totaling 96 hours of sampling, resulting in 58 individuals of 3 genera and 10 species. Euglossa Latreille, 1802 was the most abundant genus, followed by Eufriesea Cockerell, 1909 and Eulaema Lepeletier, 1841. The most frequent species were Euglossa cordata (Linnaeus, 1758), Euglossa gaianii Dressler, 1982 and Euglossa modestior (Dressler, 1982). Eucaliptol was the most attractive chemical bait. The highest frequencies of visits were in the morning and the highest abundance in September, in the drought period, and December, in the rainy period.

Euglossina Bees (Hymenoptera: Apidae) in an area with sandbanks in the northeast of the State of Maranhão, Brazil

The bees of subtribe Euglossina are an important component of neotropical fauna and have greater species diversity in tropical forests than in spits. They play an important role in the pollination of several plant species and are considered good indicators of environmental conditions. From February 2005 to January 2006, a total of 429 specimens belonging to three genera [Euglossa (Latreille), Eulaema (Lepeletier) and Eufriesea (Cockerell)] and 14 species were collected. Eulaema cingulata (Fabricius) (24.5%), Euglossa cordata (L.) (20.5%) and Eufriesea nigrescens (Friese) (19.8%) were the most abundant species, representing 64.8% of all bees collected. Rainfall was the environmental variable with the greatest relative influence on species composition, particularly for some species of Eufriesea. Euglossa cordata and Eg. gaianii Dressler nested in trap nests, suggesting they are resident species. The larger number of individuals and greater richness of species compared with data available in the literature may result from the great variety of plant species found in the areas adjacent to the collection site.

ABELHAS SOCIAIS (HYMENOPTERA : APIDAE) E SEUS RECURSOS FLORAIS EM UMA REGIÃO DE MATA SECUNDÁRIA, ALCÂNTARA, MA, BRASIL

Monthly collects were made during a year (July/92 to June/93) in an area with secondary forest near thePepital river with 1,650 m2, in Alcantara - MA, in order to know Apid fauna and their relationships with local flora. An amount of 1,076 bees (1,073 females and 3 males) were collected, belonging to 20 species and 11 genera of the Apidae family. The most abundant species were Trigona fulviventris (42.2%), Apis mellifera (24.5%), Trigona pallens(12.5%), Trigona fuscipennis(10.0%), Tetragona clavipes(2.9%) and Melipona puncticollis(2.3%). The highest number of bees was obtained in July and the smallest abundance was in April (rainy month). The highest activity of bees during the day occured from 6.00 to 8.00 a.m.. Borreria verticillata(Rubiaceae), Clusiasp. (Guttiferae), Hyptis atrorubens(Labiatae), Heliotropiumsp. (Boraginaceae) and Crotalaria retusa(Leguminosae) were intensively visited by Apidae species. Trigonawere the most generalists, visiting all the botanic species where bees were collected, with preference in Guttiferae, Rubiaceae and Boraginaceae species.

Nidificação e forrageamento de Centris (Ptilotopus) maranhensis Ducke (Hymenoptera, Apidae, Centridini)

The bees belonging to the tribe Centridini possess distribution neotropical and are considered the main pollinators of different plant species in different biomas. Despite of this the biology data of the majority of species remain scarce. This work is about observations of biology of Centris (Ptilotopus) maranhensis Ducke, 1910, specie that occurs in the Northeast of Brazil. The study was made in a cerrado area in the State of Maranhao during a period of adult activity. Females were seen nesting at epigeous termite nests and visiting Byrsonima umbellata Mart. (Malpighiaceae) flowers for oil collection. The behavior was directly registered and shooted. The nests were excavated being scraped the substratum until the cells were found. A complete nest was opened for examination of the internal structures and analysis of cells content. The general structure presented a main tunnel with cells descending linearly. Cells (n = 5) with larvae in different periods of development were found. A firmly pollen paste was seen where a huge Byrsonima grains was verified.

Dinâmica de populações de Euglossina (Hymenoptera, Apidae) em mata ciliar, Urbano Santos, Maranhão, Brasil

Males of Euglossina bees were collected in benzil benzoate, eucaliptol, eugenol, methyl salicylate and vanillin scent baits, during one year in a riparian forest area, located in the municipality of Urbano Santos, Maranhao. The collections were carried out monthly, between 8 am and 4 pm, totalling 96 hours of sampling, resulting in 283 individuals, 4 genera and 16 species. Euglossa Latreille, 1802 was the most abundant genus, followed by Eufriesea Cockerell, 1909, Eulaema Lepeletier, 1841 and Exaerete Hoffmannsegg, 1817. The most frequent species were Euglossa modestior (Dressler, 1982), Euglossa cordata (Linnaeus, 1758), Eulaema cingulata (Fabricius, 1804), Exaerete smaragdina (Guerin-Meneville, 1845), Eulaema nigrita Lepeletier, 1841 and Euglossa gaianii (Dressler, 1982). Eucaliptol was the most attractive chemical bait. The highest frequencies of visits were in the morning and the highest diversity of species occurred in the rainy period.