Declines in pollinators around the globe, notably the loss of honey bees (Apis mellifera L.) to Colony Collapse Disorder, coupled with a dearth of quantitative data on non-Apis bee pollinators, led to this dissertation research, which documents the role of non-Apis bees in crop pollination in southwest Virginia. Major findings of this first study of its kind in the region were that non-Apis bees provided the majority of pollination—measured by visitation—for several economically important entomophilous crops (apple, blueberry, caneberry, and cucurbits); diverse bee populations may be helping to stabilize pollination service (105 species on crop flowers); landscape factors were better predictors of non-Apis crop pollination service than farm management factors or overall bee diversity; and non-Apis bees in the genera Andrena, Bombus, and Osmia were as constant as honey bees when foraging on apple. Non-Apis, primarily native, bees made up between 68% (in caneberries) and 83% (in cucurbits) of bees observed visiting crop flowers. While 37–59 species visited crop flowers, there was low correspondence between bee communities across or within crop systems ("within crop" Jaccard similarity indices for richness ranged from 0.12–0.28). Bee community diversity on crop flowers may help stabilize pollination service if one or more species declines temporally or spatially. A few species were especially important in each crop: Andrena barbara in apple; Andrena carlini and A. vicina in blueberry; Lasioglossum leucozonium in caneberry; and Peponapis pruinosa and Bombus impatiens in cucurbits. Eight species collected were Virginia state records. In models testing effects of farm management and landscape on non-Apis crop pollination service, percent deciduous forest was positively correlated in apple, blueberry, and squash, but at different scales. For apple and blueberry, pollination service declined with an increase in utilized alternative forage but was positively related to habitat heterogeneity. For squash, percent native plants also related positively, possibly due to increased presence of bumble bees in late summer. Species collected from both bowl traps and flowers was as low as 22% and overall site bee diversity had no effect on crop pollination service, highlighting the value in pollination research of monitoring bees on flowers. / Ph. D.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / The research was carried out between July and December 2009 using tropical soya bean (Glycine max (L.) Merril) cultivars irrigated by center pivots in the irrigation district of Jaguaribe-Apodi, belonging to the agribusiness Faedo Sementes situated at the Apodi plateau, Limoeiro do Norte, CearÃ, Brazil. The study aimed to investigate the use of Apis mellifera L. for pollination and productivity increment in the soya bean cultivars Monsoy 9144RR, BRS-CarnaÃba, BRS-SambaÃba, adapted for the tropical conditions of N and NE Brazil. The following aspects were investigated: floral biology, pollination requirements, pollination efficiency of A. mellifera ; behavior and pattern of foraging; use of A. mellifera to augment productivity per Ãrea, per plant, in oil and protein content; and potential for honey production in soya bean crops and risks of pesticide contamination of the honey. Results showed that the cultivars are attractive to honey bees and they concentrate their foraging for nectar collection in the morning shift. The varieties were capable of autopollination, however there were significant (p<0.05) increments of productivity when flowers were visited by biotic agents. A single honey bee visit raised productivity to equivalent (p>0.05) levels of those flowers open for pollination. Regarding absolute production, it differed significantly (p<0.05) from the areas where honey bees were introduced in the center or along the sideline of the plantation to that where flowers did not receive flower visits. The mean number of pods per plant was 49.64  2.64, 57.16  2.41 and 59.60  2.71; the mean number of seeds per plant was 104.68  5.13, 121.46  3.98 and 127.42  5.95; and the percentage of pods bearing three seeds was 18.65%, 20.43% and 23.72% for the caged, open and open + honey bees treatments, respectively. Oil and protein contents of seeds did not differ (p>0.05) among treatments. All colonies produced honey and by the end of the blooming period (30 days) total production reached 81.7 kg, with a mean production of 10.1  0.86 kg per hive and no pesticide residue was found. It was concluded that the soya bean cultivars adapted to N and NE Brazil can be used for honey production and the foraging behavior of A. mellifera visiting flowers only in the morning allows to recommend spraying the crop only in the late afternoon and early evening when bees are no longer in the crop to produce residue-free honey and prevent poisioning risks to the bees; also, introducing A. mellifera for pollination purpose can increase production over 25% especially due to augment in the percentage of three-seeded pods. / A pesquisa foi conduzida entre julho e dezembro de 2009 usando cultivares tropicais de soja (Glycine max (L.) Merril) irrigadas por pivà central no distrito de irrigaÃÃo Jaguaribe-Apodi, sendo o plantio pertencente à agroempresa Faedo Sementes situada na Chapada do Apodi, Limoeiro do Norte, CearÃ. O estudo teve por objetivo investigar o uso de Apis mellifera L. para polinizaÃÃo e incrementos de produtividade nas cultivares de soja Monsoy 9144RR, BRS-CarnaÃba, BRS-SambaÃba, adaptadas Ãs condiÃÃes tropicais do Norte e Nordeste brasileiro. Os seguintes aspectos foram investigados: biologia floral, requerimentos de polinizaÃÃo, eficiÃncia de polinizaÃÃo de A. mellifera; comportamento e padrÃo de forrageamento; uso de A. mellifera para elevar a produtividade por Ãrea, por planta, em conteÃdo de Ãleo e proteÃna dos grÃos; potencial para a produÃÃo de mel e os riscos de contaminaÃÃo deste mel. Os resultados mostraram que as cultivares estudadas sÃo atrativas para as abelhas melÃferas e elas concentram seu forrageio na coleta de nÃctar no turno da manhÃ. As variedades sÃo capazes de se autopolinizarem, contudo houve incrementos de produtividade significativos (p<0,05) quando as flores foram visitadas por agentes biÃticos. Uma Ãnica visita da abelha melÃfera elevou a produtividade para nÃveis equivalentes (p>0.05) ao das flores abertas para polinizaÃÃo. No que se refere à produÃÃo total, observou-se diferenÃas significativas (p<0,05) das Ãreas onde as abelhas foram introduzidas no centro ou ao longo da linha lateral do plantio para a Ãrea cujas flores nÃo receberam visitas. O nÃmero mÃdio de vagens por planta foi 49,64  2,64, 57,16  2,41 e 59,60  2,71; o nÃmero mÃdio de grÃos por planta foi 104,68  5,13, 121,46  3,98 e 127,42  5,95; e o percentual de vagens com trÃs grÃos foi 18,65%, 20,43% e 23,72% para os tratamentos onde as plantas foram engaioladas para nÃo receberem visitantes florais, deixadas abertas para receberem visitantes florais e aberta + a introduÃÃo de colÃnias de abelhas melÃferas, respectivamente. Os conteÃdos de Ãleo e proteÃna nÃo diferiram (p>0,05) entre os tratamentos. Todas as colÃnias produziram mel e ao final do florescimento (30 dias) a produÃÃo total alcanÃou 81,7 kg, com uma produÃÃo mÃdia por colmÃia de 10,1  0,86 kg e nenhum resÃduo de pesticida foi identificado no mel. Concluiu-se que as cultivares de soja adaptadas ao Norte e Nordeste do Brasil podem ser usadas para a produÃÃo de mel e o comportamento de forrageio de A. mellifera visitando flores somente no perÃodo da manhà permite recomendar a aplicaÃÃo de defensivos apenas no final da tarde ou cedo da noite, quando as abelhas nÃo se encontram no plantio para produzir mel livre de resÃduos de pesticidas e prevenir riscos de envenenamento das abelhas; tambÃm, a introduÃÃo de A. mellifera para polinizaÃÃo pode elevar a produtividade em mais de 25%, principalmente devido ao aumento no percentual de vagens com trÃs grÃos.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / The purpose of this thesis was to investigate the feasibility of using the honey bee (Apis mellifera L.) for pollination and yield increment in Jatropha curcas L. crops. Therefore, the floral biology and pollination process of J. curcas were studied as well as the foraging behavior and pollination efficiency of A. mellifera in this crop by the introduction of four colonies in a hectare. The work was carried out in a five years-old commercial plantation comprising 10ha, in the state of PiauÃ, (08Â32â19,0âS and 43Â56â19,7âW, 220 meters above sea level), Brazil, from March to July, 2009. Flowers were presented in protogynous inflorescences and the anthesis and most of pollen presentation took place mainly in the morning shift. Inflorescences last, in average, 20 days, with female flowers concentrating in the first third of the period and male flowers predominating in the second third, in a relation of 18.1:1 male/ female flower. Although this may favor xenogamy, the stigma receptivity lasts for, at least, five days ensuring the flower to reach the period of most pollen release in its own inflorescence, facilitating the occurrence of geitonogamy. Flowers pollinated up to four days after anthesis did not differ (p>0.05) in fruit setting to those pollinated in the first, second or third day after anthesis. Foraging by A. mellifera occurs throughout the day and peaks between 13h00min and 15h00min and is characteristic of nectar harvesting both in male and female flowers. Only one visit by A. mellifera to J. curcas flowers set 100% producing results similar (p>0,05) to those from manual xenogamy (96%), manual geitonogamy (94%) and open pollination (93%). However, only one visit by a bee was not enough to maximize the oil content per seed (213mg) in comparison to the open pollination and geitonogamy treatments (both 250mg). Besides that, it was possible to observe that geitonogamy led to greater oil production than xenogamy (237mg). It is concluded that A. mellifera is an efficient pollinator of this crop. The introduction of four honey bee colonies per hectare maximize oil production and produce the best results for all parameters studied. Furthermore, only one visit by the honey bee to J. curcas flowers was enough to prevent pollination deficit in this crop. / O objetivo desta tese foi investigar a possibilidade da utilizaÃÃo de Apis mellifera L. na polinizaÃÃo e incremento de produtividade da cultura do pinhÃo manso (Jatropha curcas L.). Para tanto, foi estudado a biologia floral e a polinizaÃÃo do pinhÃo manso bem como o comportamento forrageiro e a eficiÃncia polinizadora de Apis mellifera. O trabalho foi realizado em 10ha de plantio comercial jà estabelecido, com cinco anos de idade, no estado do PiauÃ, (08Â32â19,0âS e 43Â56â19,7âW e 220 metros de altitude), entre os meses de marÃo e julho de 2009. A antese das flores do pinhÃo manso, distribuÃdas em cimos com carÃter protogÃnico, ocorre basicamente no perÃodo matinal, bem como a maior oferta de pÃlen. As inflorescÃncias duram, em mÃdia, 20 dias, com maior concentraÃÃo de flores femininas no terÃo inicial e de masculinas, no terÃo mÃdio, com relaÃÃo de 18,1 flores masculinas para cada feminina. Embora esse fato favoreÃa a xenogamia, a receptividade do estigma por, pelo menos, cinco dias, garante a flor alcanÃar o perÃodo de maior oferta de pÃlen no prÃprio cimo, oportunizando a geitonogamia. As flores polinizadas atà o quarto dia frutificam da mesma forma que aquelas polinizadas no primeiro, segundo e terceiro dias apÃs antese, nÃo havendo diferenÃas significativas. O forrageamento por A. mellifera ocorre durante todo o dia, com maior pico entre 13h00m e 15h00m e à tÃpico de coleta de nÃctar, tanto nas flores masculinas quanto nas femininas. Apenas uma visita da abelha Ãs flores acarreta em 100% de vingamento, mostrando resultado semelhante, (p>0,05), aos tratamentos de xenogamia manual (96%), geitonogamia manual (94%), e polinizaÃÃo aberta (93%). PorÃm, uma visita apenas, nÃo à suficiente para produzir maior quantidade de Ãleo por semente (213mg), em comparaÃÃo com o tratamento de polinizaÃÃo aberta, e por geitonogamia (250mg). AlÃm disto, foi possÃvel constatar que hà maior produÃÃo de Ãleo por geitonogamia e nÃo por xenogamia (237mg). Conclui-se que a Apis mellifera à um polinizador eficiente da cultura. Sua introduÃÃo, com quatro colÃnias por hectare, maximiza a produÃÃo de Ãleo e produz os melhores resultados para todos os parÃmetros avaliados. AlÃm disso, apenas uma visita da abelha melÃfera Ãs flores do pinhÃo manso à suficiente para prevenir dÃficit de polinizaÃÃo.

Les insectes contribuent à la pollinisation de 70% des espèces cultivées aujourd’hui à travers le monde. Avec l’intensification de l’agriculture au début du XXème siècle, les agriculteurs se sont mis à introduire des colonies d’abeilles mellifères dans leurs cultures entomophiles pour assurer le service de pollinisation. Avec la reconnaissance croissante du rôle majeur joué par les insectes sauvages dans la pollinisation des cultures, le concept de pollinisation intégrée des cultures a récemment vu le jour, encourageant à combiner insectes pollinisateurs introduits et sauvages en adaptant les pratiques agricoles pour assurer une pollinisation durable des cultures. Mais l’introduction d’insectes pollinisateurs d’élevage est une pratique encore très empirique qui manque de références techniques pour pouvoir être mise en œuvre avec précision. L’objectif général de cette thèse était de fournir des éléments pour mettre au point une méthode objective pour définir la charge en unités opérationnelles d’abeilles mellifères à introduire par unité de surface de culture cible pour complémenter la faune pollinisatrice sauvage pour que la pollinisation ne soit pas un facteur de production limitant.Nous avons travaillé sur une lignée mâle fertile et une lignée mâle stérile de colza (Brassica napus L.), les productions de semence hybride dépendant entièrement des insectes pour la pollinisation chez cette espèce. Nous avons pu déterminer (i) le nombre minimum de grains de pollen viables devant être déposés par stigmate pour que la grenaison puisse être complète en fonction de la température, (ii) la durée après anthèse pendant laquelle le pollen doit être déposé sur le stigmate pour que la grenaison puisse être complète en fonction de la température, (iii) la durée pendant laquelle une fleur sécrète du nectar en fonction de la température pour chacune des deux lignées, et (iv) la vitesse de cette sécrétion nectarifère en fonction de la température pour chacune des deux lignées. Nous avons également validé une méthode d’évaluation rapide de la taille des cheptels d’abeilles mellifères introduits dans les cultures entomophiles, couramment utilisée dans certains pays, en tenant compte de la température.A partir de ces éléments, nous avons proposé d’introduire les concepts d’offre et de demande en pollinisation d’une culture cible, afin de quantifier les déficits de pollinisation et le nombre d’insectes pollinisateurs à introduire pour compléter ces déficits. Ces premiers éléments fournissent une base pour construire un modèle mécaniste de gestion intégrée de la pollinisation, pour prédire le nombre d’insectes pollinisateurs à introduire dans une culture étant donné son contexte climatique, paysager et variétal. / Insects contribute to the pollination of 70% of the species cultivated today around the world. With the agriculture intensification in the early twentieth century, farmers began to introduce honey bees colonies into their entomophilous crops to provide pollination service. With the growing recognition of the major role played by wild insects in crop pollination, the concept of integrated crop pollination recently emerged, encouraging the combination of introduced and wild pollinating insects by adapting agricultural practices to ensure sustainable pollination of crops. But the introduction of managed pollinating insects is still an empirical practice that lacks technical references to be implemented with precision. The general objective of this thesis was to provide elements to develop an objective method to define the operational unit load of honey bees to be introduced per unit area of target crop to complement wild pollinating fauna so that pollination is not a limiting factor for production.We worked on a male fertile and a male sterile oilseed rape (Brassica napus L.) lines, hybrid seed productions being entirely dependent on insects for pollination in this species. We were able to determine (i) the minimum number of viable pollen grains to be deposited on stigma so that seed set was complete depending on the temperature, (ii) the duration after anthesis during which the pollen must be deposited on the stigma so that seed set was complete depending on the temperature, (iii) the length of time a flower secretes nectar as a function of temperature for each of the two lines, and (iv) the rate of this nectar secretion as a function of temperature for each of the two lines. We also validated a method for rapid assessment of the size of honey bee stocking rate introduced into entomophilous crops, commonly used in some countries, taking into account temperature.From these elements, we proposed to introduce the concepts of supply and demand in pollination of a target crop, in order to quantify the pollination deficits and the number of pollinating insects to introduce to complete these deficits. These first elements provide a basis for constructing a mechanistic model of integrated pollination management, to predict the number of pollinating insects to be introduced into a crop given its climatic, landscape and varietal context.