Os visitantes florais de Eriope blanchetii (Benth.)Harley (Labiatae) nas dunas de Abaeté, Salvador, Bahia

This work investigates the temporal variation in composition and activity of floral visitors of Eriope blanchetii (Benth.)Harley, emphasizing the effect of the duration of the flowering period and its intensity upon frequency of visits by the dominant species. The observations were conducted from October 1999 to October 2000 on a wild population of E. blanchetii located at Área de Proteção Ambiental das Lagoas e Dunas do Abaeté - APA (1206’S, 38021’W), in Salvador, state of Bahia. In total, 354 visiting insects were collected on the flowers and the Hymenoptera group predominated. The solitary bees were the most representative group (85%) of all visitors caught. Other insect visitors (15%) included Hymenoptera such as Formicidae (4%) and Vespoidea (4.5%) and also Lepidoptera (4.25%), Diptera (1.7%), and Coleoptera (0.3%). Xylocopa cearensis Ducke, 1910 (28.32%),Pseudoaugochloropsis pandora Smith, 1853 (15.30%), and Colletes petropolitanus Della Torre, 1896 (9.39%) were the predominant species. They were active during all day long, coinciding with anthesis. The number of visiting bees was higher in plants with longer flowering period and which produced numerous flowers. The diversity and number of flower visiting bees was greater during the flowering peaks, while the other insects were more abundant and diverse during low flowering.Este estudo investiga as oscilações temporais na composição e atividade dos visitantes florais de Eriope blanchetii (Benth.)Harley, enfatizando a influência da duração e intensidade da floração na freqüência de visita das espécies de abelhas predominantes. As observações foram feitas entre outubro de 1999 e outubro de 2000, em uma população natural localizada na Área de Proteção Ambiental das Lagoas e Dunas do Abaeté - APA (12056’S, 38021’W), Salvador, Bahia. Foram coletados 354 insetos visitantes das flores de E. blanchetii, sendo os Hymenoptera o grupo predominante. As abelhas solitárias formam o grupo mais representativo (85%), do total de visitantes. Os demais insetos coletados (15%) incluem outros Hymenoptera como Formicidae (4%) e Vespoidea (4,5%), além das ordens Lepidoptera (4,25%), Diptera (1,7%) e Coleoptera (0,3%). As espécies predominantes foram Xylocopa cearensis Ducke, 1910 (28,32%), Pseudoaugochloropsis pandora Smith, 1853 (15,30 %) e Colletes petropolitanus Della Torre, 1896 (9,39%). Todas estão ativas durante todo o dia, em período coincidente com a antese na população. O número de abelhas visitantes é maior nas plantas com duração e intensidade de floração elevada. A diversidade e o número de abelhas visitantes elevam-se no período de pico, enquanto os demais insetos são mais abundantesdurante a baixa floração

Aspectos da estratégia reprodutiva de duas espécies co-ocorrentes de Senna (K. Bauhin) P.Miller (Caesalpiniaceae) nas dunas do Médio Rio São Francisco, Bahia

The flower visitors and the co-existence strategies of Senna gardneri (Benth.)H.S.Irwin & Barneby and Senna macranthera var. pudibunda (Benth.)H.S.Irwin & Barneby, two sympatric species from the continental sand dunes of middle São Francisco River, Bahia (10º47’37’’S, 42º49’25”W), were investigated from February to December 2000. These species have blossoms with hermaphrodite yellow flowers, poricide anthers and produce pollen as the sole reward to the visitors. Senna gardneri produced most of the flowers at the end of the rainy season and S. macranthera var. pudibunda at the beginning of the dry season. Senna gardneri was visited by 13 bee species (n=227) with Trigona spinipes (Fabricius, 1793) (55.5%), Frieseomelitta silvestrii languida (Moure, 1989) (12.7%), and Xylocopa grisescens Lepeletier, 1841 (7.9%) as the most abundant species. Senna macranthera var. pudibunda received visits of 14 species (n=178) with predominance of T. spinipes (40%), Augocloropsis calicroa Cockerell, 1900 (27%), and F. s. languida (15.8%). The temporal separation in the flowering period between Senna species, the great quantity of flowers produced from these species and the low similarity of the flower visitors attracted to them seems to be the factors responsable for the co-occurance of Senna species in that area.A composição dos visitantes florais e as estratégias de co-existência de Senna gardneri (Benth.) H.S.Irwin & Barneby e Senna macranthera var. pudibunda (Benth.)H.S.Irwin & Barneby, duas espécies co-ocorrentes nas dunas interiores do Médio Rio São Francisco, Bahia (10º47’37’’S, 42º49’25”W), foram investigadas no período de fevereiro a dezembro de 2000. Essas espécies apresentam inflorescências com flores hermafroditas, amarelas, anteras poricidas e disponibilizam apenas pólen aos visitantes.Senna gardneri produziu o maior número de flores no final da estação chuvosa e S. macranthera var. pudibunda no início do período seco. Senna gardneri foi visitada por 13 espécies de abelhas (n=227) sendo as mais abundantes Trigona spinipes (Fabricius, 1793) (55,5%), Frieseomelitta silvestrii languida (Moure, 1989) (12,7%) e Xylocopa grisescens Lepeletier 1841 (7,9%). Senna macranthera var. pudibunda recebeu a visita de 14 espécies (n=178), com predominância de T. spinipes (40%), Augocloropsis calicroa Cockerell, 1900 (27%) e F. s. languida (15,8%). A separação temporal no período de floração entre as espécies de Senna, a grande quantidade de flores disponibilizadas por essas espécies e a baixa similaridade de visitantes florais atraídos parecem ser os fatores responsáveis pela co-ocorrência das espécies de Senna nas dunas do médio Rio São Francisco

Análise do padrão de uso de recursos florais por duas espécies de Melipona Illiger, 1806 (Hymenoptera: Apidae) nas dunas interiores do médio Rio São Francisco, Bahia, Brasil

The populations of Melipona (Eomelipona) asilvai Moure, 1971 and Melipona (Melipona) mandacaia Smith, 1863 resident in continental sand dunes from the medium São Francisco River were studied in order to verify if these bee species show low similarity in floral resource use. The bees were captured on the flowers, using entomological nets, from 6:00 a.m. to 5:00 p.m., in a restricted area (10 ha) covered with “caatinga” vegetation from February to December 2000. The flowering plants were collected and identified, and the number of flowers was estimated. 131 individuals of the species M. asilvai (53.4%) and M. mandacaia (46.6%) were sampled visiting flowers of 14 plant species (7 families). The most visited plant species were Byrsonima gardnerana Adr.Juss. (Malpighiaceae) (45.8%), Copaifera coriacea Mart. (Leguminosae: Caesalpinioideae) (12.2%), and Serjania comata Radlk. (Sapindaceae) (11.4%). Melipona bees concentrated their activities on “mass flowering” plant species and were observed foraging mainly from 06:00h to 08:00h a.m. No relation was observed between the number of bees sampled and the total of flowers estimated. This suggests that the quantity of trophic resources was not limiting. The low similarity value in the use of trophic resources between the melipona species suggests that they partition resources in the study area.As populações de Melipona (Eomelipona) asilvai Moure, 1971 e Melipona (Melipona) mandacaia Smith, 1863, residentes nas dunas interiores do médio Rio São Francisco, foram estudadas com o objetivo de verificar se essas abelhas apresentam baixa similaridade no uso de recursos tróficos. As abelhas foram coletadas nas flores utilizando-se redes entomológicas, das 6:00h às 17:00h, em uma área restrita (10 ha) com vegetação de caatinga, no período de fevereiro a dezembro de 2000. As plantas floridas foram coletadas, identificadas e o número de flores foi estimado. Amostrou-se um total de 131 indivíduos, sendo 53,4% de M. asilvai e 46,6% de M. mandacaia, visitando as flores de 14 espécies vegetais (7 famílias). As espécies vegetais predominantemente visitadas foram Byrsonima gardnerana Adr.Juss. (Malpighiaceae) (45,8%), Copaifera coriacea Mart. (Leguminosae: Caesalpinioideae) (12,2%) e Serjania comata Radlk. (Sapindaceae) (11,4%). As melíponas concentraram suas atividades em poucas espécies vegetais com floração massal e apresentaram maior atividade diária das 6:00h às 8:00h. Não houve relação entre o número de indivíduos coletados e o número de flores estimadas, sugerindo que a quantidade de recursos não foi limitante. O baixo valor de similaridade no uso de recursos tróficos sugere que essas espécies partilham recursos tróficos na área

Aspectos da nidificação e forrageamento de Xylocopa (Neoxylocopa) grisescens Lepeletier, 1841 (Hymenoptera: Apidae: Xylocopini) nas dunas do médio São Francisco, Bahia

Xylocopa (Neoxylocopa) grisescens Lepeletier, 1841 (Hymenoptera: Apidae: Xylocopini) was the most abundant species of this genus in the study area. Nests were found in the riparian forests of the mid San Francisco River. The architecture of five X. grisescens nests built in branches of Capparis sp. (Capparaceae) are described. The length and diameter of the nesting substrates varied between 68-87cm and 17-23cm, respectively. Each nest had one rounded entrance with mean diameter of 16.0mm ± 1.08mm (n=7). Cells were barrel-shaped in linear series in the galleries, with 2.40cm ± 0.18cm in length, 2.01cm ± 0.11cm in diameter and a mean volume of 7.59cm ± 0.79cm3. Cell partitions were 3.49mm ± 0.28mm thick (n=15) at the margins, where they are thicker. X. grisescens visited 12 plant species (six families). The most frequently visited plant species were Senna Gardneri (Benth.) Irwin & Barneby (32%), S. macranthera (Collad.) Irwin & Barneby var. pudibunda (18%), Proterantha glandulosa sp. n. (15%) and Dioclea marginata Benth. (15%).Xylocopa (Neoxylocopa) grisescens Lepeletier, 1841 (Hymenoptera: Apidae: Xylocopini) foi a espécie mais abundante do gênero, amostrada nas flores, em uma área das dunas do médio Rio São Francisco. A arquitetura de cinco ninhos de X. grisescens construídos em galhos de Capparis sp. (Capparaceae) foi descrita. O comprimento e o diâmetro dos substratos dos ninhos variaram de 68-87cm e 17-23cm, respectivamente. Cada ninho apresenta uma entrada circular com diâmetro médio de 15,95 ± 1,08mm (n=7). As células possuem a forma de barril com 2,40 ± 0,18cm de comprimento, 2,01 ± 0,11cm de diâmetro e 7,59 ± 0,79cm3 de volume. As divisórias entre as células possuem, em media, 3,49 ± 0,28mm de espessura (n=15) medida na borda a qual é um pouco mais espessa do que o centro. X. grisescens visitou 12 espécies de plantas de seis famílias, mas concentaram suas atividades em apenas quatro espécies que receberam 80% das visitas: Senna gardneri (Benth.) Irwin & Barneby (32%), S. macranthera (Collad.) Irwin & Barneby var. pudibunda (18%), Proterantha glandulosa sp. n. (15%) e Dioclea marginata Benth. (15%)

Non-bee insects are important contributors to global crop pollination

Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25–50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

Delivery of crop pollination services is an insufficient argument for wild pollinator conservation

There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments

Structure of bee-flower system in the coastal sand dune of Abaeté, northeastern Brazil

For twelve months (from January to December of 1996) we investigated bee-flower interactions in a sea coastal ecosystem in Bahia, Brazil. Samples were taken three times each month. 3983 individuals belonging to 49 bee species, grouped in 13 morph-functional categories, visited 66 plant species belonging to 39 botanic families. It was observed 310 interactions between bees and plants at species level. The use of floral resources by bees was not homogeneous; most of the plant species received a low number of visitors. No restricted plant-bee species relationship in resource use concerning the subset of analyzed interactions was detected. In Abaeté the generalist relationships predominated