Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 42-52).

Thesis (M.S. in entomology)--Washington State University, May 2010. / Title from PDF title page (viewed on July 12, 2010). "Department of Entomology." Includes bibliographical references.

Thesis (M.S.)--Rhodes University, 2003. / Title from PDF t.p. (viewed on June 9, 2006). Includes bibliographical references (p. 110-122).

Orientador: José Chaud Netto / Banca: Valter Vieira Alves Júnior / Banca: Júlio Valentim Betioli / Resumo: No presente estudo avaliou-se o efeito do macerado floral e de extratos folhares de L. camara em operárias de Apis mellifera. Abelhas africanizadas recém-emergidas foram coletadas e marcadas, sendo posteriormente introduzidas em um núcleo contendo 3 favos cobertos por abelhas adultas e apresentando boa quantidade de mel e pólen. Dois desses favos possuíam um grande número de operárias em diferentes fases de desenvolvimento. Sete dias após a marcação as abelhas foram transferidas para caixas de laboratório mantidas em estufa bacteriológica a 34° C l 1° C e umidade relativa de 60 l 5%. Nas primeiras séries de bioensaios, em que foi testado o macerado floral, os grupos experimentais receberam pasta-cândi acrescida do macerado em concentrações variadas (30%, 10%, 7,5%, 5% e 2,5%), enquanto as abelhas dos grupos-controle receberam somente cândi. Os resultados das análises de sobrevivência indicaram que as abelhas alimentadas com cândi acrescido do macerado floral a 30%, 10% e 7.5% apresentaram uma menor longevidade (P < 0,0001), em relação às operárias dos grupos-controle. Estes resultados sugerem a existência de alguma substância tóxica no macerado floral de L. camara capaz de diminuir a longevidade das operárias. Na segunda série de bioensaios, as operárias receberam, por meio de aplicação tópica na região do pronoto, 2æL do extrato metanólico das folhas de L. camara nas concentrações de 0,0888 mg/abelha, 0,0444 mg/abelha e 0,0222 mg/abelha, enquanto que as abelhas do grupo controle receberam somente metanol. As análises de sobrevivência revelaram que os extratos de L. camara não interferiram na longevidade das operárias / Abstract: In this study the effect of the floral crushed and foliage extracts of L. camara in Apis mellifera workers was evaluated. Newly-emerged Africanized honeybee workers were collected and marked, being later introduced in a beehive containing three frames covered with bees and presenting good amount of honey, pollen and a great number of workers in different phases of development. Seven days after, the bees were transferred to laboratory boxes maintained in a bacteriological stove at 34° C l 1° C and relative humidity of 60 l 5%. In the first series of bioassays the honeybee workers of the experimental groups received candy plus floral crushed of L. camara in variable concentrations (30%, 10%, 7.5%, 5% and 2.5%), while the bees of the control groups were fed only with candy. The survival analyses indicated that bees fed with candy plus the floral crushed at 30%, 10% and 7.5% have a shorter life time (P <0,0001), in relation to the workers of the control groups. These results suggest the presence of some toxic substance in the floral crushed of L. camara, able to diminish the life time of adult workers. In the second series of bioassays the honeybee workers received, by topical application on the pronotum, 2æL of methanolic extracts of L. camara leaves in the concentrations of 0,0888 mg/bee, 0,0444 mg/bee and 0,0222 mg/bee, while the workers of the control groups received only methanol. The survival analyses revealed that the extracts of L. camara did not affect the worker's longevity / Mestre

Made available in DSpace on 2014-06-11T19:30:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-10-27Bitstream added on 2014-06-13T19:18:42Z : No. of bitstreams: 1 pereira_am_me_rcla.pdf: 453810 bytes, checksum: 9d141c92ea13cc88e6e95ae064e3bba4 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / No presente estudo avaliou-se o efeito do macerado floral e de extratos folhares de L. camara em operárias de Apis mellifera. Abelhas africanizadas recém-emergidas foram coletadas e marcadas, sendo posteriormente introduzidas em um núcleo contendo 3 favos cobertos por abelhas adultas e apresentando boa quantidade de mel e pólen. Dois desses favos possuíam um grande número de operárias em diferentes fases de desenvolvimento. Sete dias após a marcação as abelhas foram transferidas para caixas de laboratório mantidas em estufa bacteriológica a 34° C l 1° C e umidade relativa de 60 l 5%. Nas primeiras séries de bioensaios, em que foi testado o macerado floral, os grupos experimentais receberam pasta-cândi acrescida do macerado em concentrações variadas (30%, 10%, 7,5%, 5% e 2,5%), enquanto as abelhas dos grupos-controle receberam somente cândi. Os resultados das análises de sobrevivência indicaram que as abelhas alimentadas com cândi acrescido do macerado floral a 30%, 10% e 7.5% apresentaram uma menor longevidade (P < 0,0001), em relação às operárias dos grupos-controle. Estes resultados sugerem a existência de alguma substância tóxica no macerado floral de L. camara capaz de diminuir a longevidade das operárias. Na segunda série de bioensaios, as operárias receberam, por meio de aplicação tópica na região do pronoto, 2æL do extrato metanólico das folhas de L. camara nas concentrações de 0,0888 mg/abelha, 0,0444 mg/abelha e 0,0222 mg/abelha, enquanto que as abelhas do grupo controle receberam somente metanol. As análises de sobrevivência revelaram que os extratos de L. camara não interferiram na longevidade das operárias. / In this study the effect of the floral crushed and foliage extracts of L. camara in Apis mellifera workers was evaluated. Newly-emerged Africanized honeybee workers were collected and marked, being later introduced in a beehive containing three frames covered with bees and presenting good amount of honey, pollen and a great number of workers in different phases of development. Seven days after, the bees were transferred to laboratory boxes maintained in a bacteriological stove at 34° C l 1° C and relative humidity of 60 l 5%. In the first series of bioassays the honeybee workers of the experimental groups received candy plus floral crushed of L. camara in variable concentrations (30%, 10%, 7.5%, 5% and 2.5%), while the bees of the control groups were fed only with candy. The survival analyses indicated that bees fed with candy plus the floral crushed at 30%, 10% and 7.5% have a shorter life time (P <0,0001), in relation to the workers of the control groups. These results suggest the presence of some toxic substance in the floral crushed of L. camara, able to diminish the life time of adult workers. In the second series of bioassays the honeybee workers received, by topical application on the pronotum, 2æL of methanolic extracts of L. camara leaves in the concentrations of 0,0888 mg/bee, 0,0444 mg/bee and 0,0222 mg/bee, while the workers of the control groups received only methanol. The survival analyses revealed that the extracts of L. camara did not affect the worker's longevity.

This diploma thesis compiles the general theoretical outline of the subject honeybee, analysisof RVP and school books for science and nature studies. Further this work presents themes and proposals for the subject of general science and nature studies with the use of interrelationships between schools subjects. It also evaluates realizations of some of these proposals in practice.

The discovery of the honeybee-specific ectoparasitic mite Varroa destructor in South Africa in October 1997 raised the spectre of massive honeybee colony losses as has occurred in most parts of the world where the varroa mite has been found. This was particularly concerning in Africa because of the importance of honeybees in the pollination of indigenous and commercial crops, and because of the numbers of small-scale beekeepers in Africa. The mite has now spread throughout South Africa and is found in almost all honeybee populations, both commercial and wild, and is also now present in most neighbouring countries. Varroa has not left a trail of destruction in South Africa as had been expected and no large scale collapse of the honeybee population occurred, despite the majority of beekeepers deciding not to protect their hives with chemical varroacides. Some colony losses did occur at the front of the varroa spread, and all colonies were found to be deleteriously affected by the mite which developed populations of 50 000 and more in some colonies. Infected colonies were also not as efficient as pollinators as uninfected colonies. Colonies exhibited all the same varroa effects witnessed in other parts of the world, with the exception that the majority of colonies did not die as a result of the infestation. The relative tolerance of African bees to the varroa mite has been confirmed by the long-term monitoring of both wild honeybee populations and commercial stock, and by population dynamic studies of the mites. In both wild and managed honeybee populations varroa appears to have been reduced to the status of an incidental pest. The development of mite tolerance took 3-5 years in the Cape honeybee (Apis mellifera capensis) and 6-7 years in the Savanna honeybee (Apis mellifera scutellata). The rapid development of mite tolerance in the Cape bee is thought to be due to the well developed removal of varroa-infested brood and the short post-capping period of worker brood. Together these resulted in a very rapid increase in infertile mites in the colony, the collapse of the mite population, and varroa tolerance. Tolerance does not develop as rapidly in Savanna honeybees as the post-capping period in these bees is similar to that of European bees and does not result in as many infertile mites. Nonetheless, varroa tolerance in Savanna bees develops more rapidly than would be the case in European bees because of more effective hygienic removal of varroa-infested brood. In both Cape and Savanna bees, the absence of varroacide applications and a “live-and-let-die” approach to the wild and commercial honeybee populations was crucial to the developed of population-wide varroa tolerance, in contrast to the selective breeding and pesticide treadmill practised in most parts of the world in an effort to get rid of the varroa mite. Varroa destructor is concluded not to be a serious threat to honeybees and beekeeping in Africa, and efforts should be made to prevent the use of pesticides and techniques that could hinder the development of natural mite tolerance in Africa. / Dissertation (MSc (Entomology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

Honeybees are one of the most important pollinating species in agriculture. Every three out of four crops have honeybee as their sole pollinator. Since 2006 there has been a drastic decrease in the bee population which is attributed to Colony Collapse Disorder(CCD). The bee colonies fail/ die without giving any traditional health symptoms which otherwise could help in alerting the Beekeepers in advance about their situation. Electronic Beehive Monitoring System has various sensors embedded in it to extract video, audio and temperature data that could provide critical information on colony behavior and health without invasive beehive inspections. Previously, significant patterns and information have been extracted by processing the video/image data, but no work has been done using audio data. This research inaugurates and takes the first step towards the use of audio data in the Electronic Beehive Monitoring System (BeePi) by enabling a path towards the automatic classification of audio samples in different classes and categories within it. The experimental results give an initial support to the claim that monitoring of bee buzzing signals from the hive is feasible, it can be a good indicator to estimate hive health and can help to differentiate normal behavior against any deviation for honeybees.

Cotton is a high-value commercial crop in Australia. Although cotton is largely self-pollinating, previous researchers have reported that honeybees, Apis mellifera, can assist in cross-pollination and contribute to improved yield. Until recently, use of bees in cotton had, however, been greatly limited by excessive use of pesticides to control arthropod pests. With the widespread use of transgenic (Bt) cotton varieties and the associated reduction in pesticide use, I decided to investigate the role and importance of honeybees in Bt cotton, under Australian conditions. I conducted two major field trials at Narrabri, in the centre of one of Australia’s major cotton-growing areas, in the 2005-6 and 2006-7 seasons. In the first trial, I particularly assessed methods of manipulating honeybee colonies by feeding pollen supplements of pollen/soybean patties, and by restricting pollen influx by the fitting of 30% efficient pollen traps. I aimed to test whether either of these strategies increased honeybee flight activity and, thus, increased foraging on cotton flowers. My results showed that although supplementary feeding increased bee flight activity and brood production, it did not increase pollen collection on cotton. Pollen traps initially reduced flight activity. They also reduced the amount of pollen stored in colonies, slowed down brood rearing activity, and honey production. However, they did not contribute to increased pollen collection in cotton. In the second trial, I spent more time investigating honeybee behaviour in cotton as well as assessing the effect of providing flowering cotton plants with access to honeybees for different time periods (e.g. 25 d, 15 d, 0 d). In this year, I used double the hive stocking rate of (16 colonies / ha) than in the previous year, because in 2005-6 I observed few bees in cotton flowers. I also conducted a preliminary investigation to assess whether there was any gene flow over a 16 m distance from Bt cotton to conventional cotton, in the presence of a relatively high honeybee population. Both of my field experiments showed that honeybees significantly increased cotton yield via increased boll set, mean weight of bolls, number of seeds / boll, and weight of lint / boll. It was obvious that cotton flowers, and particularly cotton pollen, were not attractive to honeybees, and this was also reflected in the low proportion (5.3% w/w) of pollen from cotton collected in the pollen traps. However, flower visitation rate was generally above the 0.5% level regarded as optimal for cross-pollination in cotton, and this was reflected in increased yield parameters. I recorded a gene flow of 1.7 % from Bollgard®II cotton to conventional cotton, over a distance of 16 m. This is much higher than had previously been reported for Australia, and may have been a result of high honeybee numbers in the vicinity, associated with my managed hives. In an attempt to attract more honeybees to cotton flowers, I conducted an investigation where I applied synthetic Queen Mandibular Pheromone (QMP) (Fruit Boost®) at two rates, 50 QEQ and 500 QEQ / ha, and for two applications, 2 d apart. Neither rate of QMP increased the level of bee visitation to flowers, either on the day of application or the subsequent day. There was also no increase in boll set or yield in plants treated with QMP. My observations of honeybee behaviour in cotton brought some interesting findings. First, honeybees totally ignored extra floral nectaries. Second, most flower-visiting honeybees collected nectar, but the overwhelming majority of them (84%) collected floral nectar from outside flowers: this meant these bees did not contribute to pollination. Those nectar gatherers which entered flowers did contribute to pollination. However, they were observed to exhibit rejection of cotton pollen by scraping pollen grains from their body and discarding them, prior to returning to their hives. Pollen gatherers collected only small, loose pellets from cotton. SEM studies showed that cotton pollen grains were the largest of all pollen commonly collected by bees in my investigations, and that they also had large spines. It is likely that these characteristics make cotton pollen unattractive to honeybees. Another possible reason for the unattractiveness of cotton flowers was the presence of pollen beetles, Carpophilus aterrimus, in them. I conducted a series of studies to determine the role of pollen beetles in pollination of cotton. I found that they did not contribute to pollination at low levels; at high populations they damaged flowers (with ≥ 10 beetles / flower, no flowers set bolls); and that honeybees, when given the choice, avoid flowers with pollen beetles. Because the insecticide fipronil was commonly used in Australian cotton at flowering time, and because I had some experience of its toxic effects against honeybees in my field investigations, I conducted a series of laboratory and potted plant bioassays, using young worker bees. The studies confirmed its highly toxic nature. I recorded an acute dermal LD50 of 1.9 ng / bee, and an acute oral LC50 of 0.62 ppm. Fipronil’s residual toxicity also remained high for an extended period in both laboratory and potted plant trials. For example, when applied to cotton leaves in weather-exposed potted cotton plants, it took 25 d and 20 d for full and half recommended rates of fipronil, respectively, to become non- toxic to honeybees. I had previously investigated whether a shorter period of exposure of cotton plants to honeybees would contribute adequately to increased yield, and concluded that a 10 d window within a 25 d flowering period would contribute 55% of the increase in total weight of bolls contributable to honeybee pollination, but only 36% of the increase in weight of lint. Given the highly residual activity of fipronil I recorded, the only opportunity for an insecticide-free period during flowering would be at its commencement. I concluded that, while there is evidence that honeybees can contribute to increased cotton yield in Bt cotton in Australia, this is unlikely with the continued use of fipronil at flowering. / Doctor of Philosophy (PhD)

Graduation date: 1995