Guaraci Duran Cordeiro

Crop pollinators in Brazil: a review of reported interactions

Pollinators are important to maintain ecosystem services, being part of the reproduction and seed formation process of plant species. In this study, we reviewed the literature and developed a database of interactions between pollinators and agricultural crops for Brazil. We classified the pollinators as effective, occasional, or potential, and also identified those species quoted simply as “visitors” (without reference to pollination). We found 250 crop pollinators pertaining to the three categories quoted, with 168 effective ones. Besides, we identified the effective pollinators of 75 agricultural crops. Bees pertaining to the family Apidae, mainly those from the genera Melipona, Xylocopa, Centris, and Bombus, were reportedly the most effective pollinators of agricultural crops. We also found that the exotic managed species Apis mellifera and the stingless bee Trigona spinipes are effective pollinators of some crops. In spite of some data having been originated from gray literature and the taxonomic impediment, this effort is a crucial step to clarify the gaps and bias on data. This study is the first to attempt to build, analyze, and make available a comprehensive data set about pollinators of agricultural crops in a country level, aiming to contribute to protective measures and to enhance the sustainable use of native pollinators in agriculture.

Phoretic mites (Acari: Chaetodactylidae) associated with the solitary bee Tetrapedia diversipes (Apidae: Tetrapediini)

Solitary bees of the genus Tetrapedia have a specific association with mites of the genus Roubikia (Chaetodactylidae). These mites are frequently found attached to active Tetrapedia bees. We quantified the number of mites on individuals of Tetrapedia diversipes Klug and examined the interaction between these species. Nests of T. diversipes were obtained from trap-nests placed in four localities in São Paulo, Brazil. The study lasted from March 2007 to February 2009. Out of a total of 650 nests with emergences, 118 were infested with mites (Roubikia sp.). From these nests, 176 individuals of T. diversipes emerged with mites on their bodies. Additionally, six individuals of Coelioxoides waltheriae, the specific kleptoparasitic bee to T. diversipes, emerged. Mites were attached mainly to the mesosoma. All nests infected with mites did not presented mortality of the immature. The mortality rate of nests was inversely related to the level of mite infestation, suggesting a mutualistic interaction in which mites may remove fungi from the nests, while the bees would provide the mites with transport, dispersal, and shelter.

Projected climate change threatens pollinators and crop production in Brazil.

Animal pollination can impact food security since many crops depend on pollinators to produce fruits and seeds. However, the effects of projected climate change on crop pollinators and therefore on crop production are still unclear, especially for wild pollinators and aggregate community responses. Using species distributional modeling, we assessed the effects of climate change on the geographic distribution of 95 pollinator species of 13 Brazilian crops, and we estimated their relative impacts on crop production. We described these effects at the municipality level, and we assessed the crops that were grown, the gross production volume of these crops, the total crop production value, and the number of inhabitants. Overall, considering all crop species, we found that the projected climate change will reduce the probability of pollinator occurrence by almost 0.13 by 2050. Our models predict that almost 90% of the municipalities analyzed will face species loss. Decreases in the pollinator occurrence probability varied from 0.08 (persimmon) to 0.25 (tomato) and will potentially affect 9% (mandarin) to 100% (sunflower) of the municipalities that produce each crop. Municipalities in central and southern Brazil will potentially face relatively large impacts on crop production due to pollinator loss. In contrast, some municipalities in northern Brazil, particularly in the northwestern Amazon, could potentially benefit from climate change because pollinators of some crops may increase. The decline in the probability of pollinator occurrence is found in a large number of municipalities with the lowest GDP and will also likely affect some places where crop production is high (20% to 90% of the GDP) and where the number of inhabitants is also high (more than 6 million people). Our study highlights key municipalities where crops are economically important and where pollinators will potentially face the worst conditions due to climate change. However, pollinators may be able to find new suitable areas that have the potential to improve crop production. The results shown here could guide policy decisions for adapting to climate change and for preventing the loss of pollinator species and crop production.

The Cleptoparasitic Bee Austrostelis iheringi (Schrottky, 1910) (Anthidiini, Megachilidae): New Geographical Records and Potential Hosts

Abstract Two new geographical records of Austrostelis iheringi from Atlantic Forest in the state of São Paulo, southeastern Brazil are presented. Possible hosts of this parasitic bee species include Dicranthidium seabrai Urban, Epanthidium tigrinum Schrottky, and Saranthidium musciforme Schrottky.

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.

The body size of the oil-collecting bee Tetrapedia diversipes (Apidae)

The body size of bees can affect their fitness in many ways. There is an indirect relationship between the size of the mother and the size of her progeny. This is so because large mothers use larger nests and brood cells and have higher foraging capacity than small mothers, and consequently large mothers supply a larger amount of food to their larvae, which grow larger. We analyzed the relationship between body size of individual oil-collecting bees of the species Tetrapedia diversipes and the size of their brood cells from Boraceia and Ilhabela, southeastern Brazil. In addition, we manipulated 26 brood cells of a population at the campus of Universidade de Sao Paulo by removing food from 13 brood cells. In this case, we checked the relationship between the body size of these bees and the amount of food consumed. We measured 241 individuals: 135 males and 106 females. No significant size difference was found between males and females. Only a weak relationship between body size and brood cell volume was detected, possibly due to the low variation in both female size and brood cell size. In the food manipulation experiment, the unmanipulated individuals were larger than individuals for whom part of the provisions were removed but no correlation was found between amount of food removed and offspring size.

Entering behavior of Gasteruption brachychaetum Schrottky (Hymenoptera, Gasteruptiidae) into a nest of Hylaeus Fabricius (Hymenoptera, Colletidae)

Nests of Hylaeus aff. guaraniticus (Schrottky, 1906) were parasited by females of Gasteruption brachychaetum Schrottky, 1906 in trap nests in Sao Paulo (Brazil). This is thefirst host record of a Gasteruptiidae in the Neotropical Region. The behavior of a G.brachychaetum female entering a hosts nest is described as follows: an inquiline female hovered near the hosts nest, landed and detected that a female of H. aff. guaraniticus was inside the nest, waited for the host female to fly out, entered backwards into the nest, remained there for almost six minutes, and then went out the nest. The development time of immature stages of G.brachychaetum varied between 16 and 299 days.