Cristiane Krug

A scientific note on new insights in the pollination of guarana (Paullinia cupana var. sorbilis)

Guarana (Paullinia cupana var. sorbilis (Mart.) Ducke, Sapindaceae family) is an important and traditional crop of significant economic and social importance in the Amazon region. It is a Brazilian native plant, cultivated by largeand small-scale producers (Embrapa 2005). Its fruits are dehiscent capsules that contain one or three dark brown seeds, with 2.3 to 5 % caffeine. The seeds need to be processed to obtain the powder, syrup, or extract (Angelo et al. 2008), which is used in food, beverage, and pharmaceutical products worldwide. The guarana plant is a monoecious species, with male and female flowers opening at different times (dichogamy) on the same plant (see Supplementary Material ESM1). Several studies have been conducted since the 1970s on the pollinators and floral biology of the guarana plant (Schultz and Valois 1974; Gondim 1978; Carranza et al. 1981; Erickson et al. 1984; Escobar et al. 1984; Ferreira 2003). The flowering period of P. cupana var. sorbilis varies yearly and appears to be related to rainfall patterns (Erickson et al. 1984; Escobar et al. 1984). Generally, the flowering period in the Amazon region begins in late July and ends in November when there is less rainfall. There is a gap in observations on floral visitors between 2 a.m. (at the beginning of anthesis) and 6 a.m., the time when observations began in previous studies by Schultz and Valois (1974), Gondim (1978), Escobar et al. (1984), and Ferreira (2003). According to these authors, the most effective pollinator species, based on flower observations, are the stingless bees of the genus Melipona. This preliminary study aims to answer two fundamental questions regarding the pollination ecology of P. cupana var. sorbilis as follows: (1) are there nocturnal/crepuscular flower visitors? and, if there are, (2) who are these visitors/pollinators? To evaluate the occurrence of floral visitors from the beginning of anthesis, which begins at 2 a.m., surveys were conducted between 2 and 9 a.m. for 8 days, totaling 64 h of sampling. All the censuses/surveys were conducted on clear nights during all moon phases, on nonconsecutive days. Preliminary surveys to collect and identify nocturnal and crepuscular species were made in experimental and commercial fields of flowering guarana in the counties of Manaus (21 and 29/08/2011) and Maues (28 and 29/10/2011), respectively. Additional samples, to quantify (census) the nocturnal, crepuscular, and diurnal visitors, were collected in Manaus (04, 12, 19, and 26/09/2012). Sunrise occurred from 5:37 to 6:07 a.m. during the study. Surveys were made every 30 min and each lasted 10 min. During each survey, the researcher walked slowly along the rows of guarana plants, counting the number of each type of bee (nocturnal, crepuscular, and diurnal) on the flowers in an area of 1 ha, which was surrounded by native vegetation. Due to easy recognition, the bee types were only counted as nocturnal (Megalopta spp.), crepuscular (Ptiloglossa sp.), or diurnal (all the other bees). Sampling was done using entomological nets. The flower visitors were observed and voucher specimens of the insects/bees were collected (authorization number 32357-1 MMA/ICMBio) and Electronic supplementary material The online version of this article (doi:10.1007/s13592-014-0304-3) contains supplementary material, which is available to authorized users.

Diversity of mites associated with Raoiella indica (Acari: Prostigmata) on coconut palms in the central region of the Brazilian Amazonia, with emphasis on the predaceous Phytoseiidae (Acari: Mesostigmata)

Abstract The mite Raoiella indica Hirst (Tenuipalpidae) has caused significant damage to coconut palms in the American continent and in the Caribbean area. Emphasis has been given to the establishment of sustainable measures for the control of this pest in this region, especially the use of predaceous mites. The objective of this study was to determine the occurrence of R. indica and other mites on coconut palms in Manaus (capital of the Amazonas state) and other three neighboring municipalities, at different periods of the year, with emphasis on mites of the family Phytoseiidae. Our hypothesis was that R. indica was not widespread in Manaus region, that it was found at low population levels and in association with a high diversity of predatory mites. Samples were collected at four periods, August/ September 2012 (when rainfall was lower), November/ December 2012 (beginning of the period of intense rainfall), February/ March 2013 (period of intense rainfall) and May/ June 2013 (beginning of the period with lower rainfall). Leaflets, fruits and flowers were sampled from ten plants at each sampling site (one from each municipality) and at each sampling period. Most mites were found on leaflets; 73.9% of these were predominantly phytophagous, 6.1% predominantly predaceous and 20.0% had mainly other feeding habits. Eriophyoidea, tarsonemids and tetranychids were the most abundant groups of predominantly phytophagous mites. Raoiella indica was found at low population levels and in a single site (Iranduba). Phytoseiids were by far the predominant predators (42.5% of the predaceous mites); they were most abundant during intense rainfall. Amblyseius aerialis (Muma), Euseius alatus De Leon and Amblydromalus sp. nov. were the most abundant predators of this family. Cunaxid mites accounted for 27.2% of the predaceous mites. The results of this study suggested that R. indica was not widespread in the region, that it was found at low population levels and that a great diversity of predaceous mites was found on coconut plants in that region. It remains to be seen whether these would be able to maintain the population of that pest under control.

Leprosis mite and other mite species (Acari) associated to orange groves in Brazilian Central Amazon

Abstract The citrus leprosis mite, Brevipalpus yothersi Baker, is not considered to cause major damage to orange trees in the Brazilian Amazonas state. However, little is known about the diversity of plant mites and about mite damage to plants in this state of northern Brazil. The objective of the present study was to evaluate the level of occurrence of the leprosis mite in this region and the diversity and prevailing population levels of associated mites in unsprayed orange groves of the surroundings of Manaus, Amazonas state. In total, 1,614 mites were collected on citrus trees (616 of eminently predatory groups, 541 of eminently phytophagous groups and 457 of other groups). On plants growing spontaneously in orange groves, 514 mites were collected (270 of eminently predatory groups, 26 of eminently phytophagous groups and 218 of other groups). Most predators collected (638 specimens) belonged to Phytoseiidae, representing 14 species. The most abundant phytoseiids were Amblyseius aerialis Muma and Iphiseiodes zuluagai Denmark & Muma. Only 197 B. yothersi were collected, on leaves of orange, Lantana camara L. and Solanum paniculatum L.. Leprosis symptoms were not observed, and this may be related to the relatively low densities of the leprosis mite. The plant species Borreria verticillata (L.), Clidenia hirta (L.), L. camara, Paspalum virgatum L. and S. paniculatum are reservoirs of two abundant predatory mites of orange trees, A. aerialis and I. zuluagai.

Nocturnal Bee Pollinators Are Attracted to Guarana Flowers by Their Scents

Floral scent is an important component of the trait repertoire of flowering plants, which is used to attract and manipulate pollinators. Despite advances during the last decades about the chemicals released by flowers, there is still a large gap in our understanding of chemical communication between flowering plants and their pollinators. We analyzed floral scents of guarana (Paullinia cupana, Sapindaceae), an economically important plant of the Amazon, using chemical analytical approaches, and determined the attractiveness of the scent to its nocturnal bee pollinators using behavioral assays in the field. Pollen loads of attracted bees were also analyzed. Inflorescences of guarana emit strong scents, both during day and at night, with some semi-quantitative differences between day- and night-time scents. Synthetic scent mixtures containing some of the identified floral scent components, including the most abundant ones, i.e., linalool and (E)-β-ocimene, successfully attracted the nocturnal Megalopta bee pollinators. Pollen analyses revealed that many of the attracted bees had pollen grains from previous visits to guarana flowers on their bodies. Overall, our data show that guarana flowers attract nocturnal bee visitors by their strong scents and suggest that the chemical communication between this plant and its pollinators is a key component in crop production of this economically important plant species.

Preferência do bicudo-das-palmeiras por dendezeiro, caiaué e por seu híbrido interespecífico

O objetivo deste trabalho foi determinar, em campo, a preferencia do bicudo-das-palmeiras (Rhynchophorus palmarum) por estipes de dendezeiro (Elaeis guineensis), caiaue (Elaeis oleifera) e pelo hibrido entre caiaue e dendezeiro. O experimento foi conduzido no banco de germoplasma de dende da Comissao Executiva de Planejamento da Lavoura Cacaueira. Entre os tres genotipos testados, o caiaue e significativamente menos preferido por Rhynchophorus palmarum, seguido do hibrido interespecifico e do dendezeiro.