scholarly journals Pollen Release Dynamics and Daily Patterns of Pollen-Collecting Activity of Honeybee Apis mellifera and Bumblebee Bombus lantschouensis in Solar Greenhouse

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 216 ◽  
Author(s):  
Hong Zhang ◽  
Zhiyong Zhou ◽  
Jiandong An

Pollen is important not only for pollination and fertilization of plants, but also for colony development of bee pollinators. Anther dehiscence determines the available pollen that can be collected by foragers. In China, honeybees and bumblebees are widely used as pollinators in solar greenhouse agriculture. To better understand the effect of solar greenhouse microclimates on pollen release and pollen-foraging behaviour, we observed the anther dehiscence dynamics and daily pollen-collecting activity of Apis mellifera and Bombus lantschouensis during peach anthesis in a solar greenhouse in Beijing. Microclimate factors had a significant effect on anther dehiscence and bee foraging behaviour. The proportion of dehisced anthers increased with increasing temperature and decreasing relative humidity and peaked from 11:00 h to 14:00 h, coinciding with the peak pollen-collecting activity of bees. On sunny days, most pollen grains were collected by the two pollinators within two hours after anther dehiscence, at which time the viability of pollen had not yet significantly decreased. Our study helps us to better understand the relationship between food resources and pollinator foraging behaviour and to make better use of bees for pollination in Chinese solar greenhouses.

2010 ◽  
Vol 70 (4) ◽  
pp. 1075-1081 ◽  
Author(s):  
AS. Rosa ◽  
B. Blochtein ◽  
NR. Ferreira ◽  
S. Witter

Brassica napus Linnaeus is considered a self-compatible crop; however, studies show that bee foraging elevates their seed production. Considering bee food shortages during the winter season and that the canola is a winter crop, this study aimed to evaluate the foraging behaviour of Apis mellifera Linnaeus, 1758 regarding those flowers, and to verify if it presents adequate behaviour for successfully pollinating this crop in Rio Grande do Sul State. The study was carried out in a canola field, in Southern Brazil. The anthesis stages were morphologically characterised and then related to stigma receptivity and pollen grain viability. Similarly, the behaviour of A. mellifera individuals on flowers was followed, considering the number of flowers visited per plant, the amount of time spent on the flowers, touched structures, and collected resources. Floral fidelity was inferred by analysing the pollen load of bees collected on flowers. The bees visited from 1-7 flowers/plant (x = 2.02; sd = 1.16), the time spent on the flowers varied between 1-43 seconds (x = 3.29; sd = 2.36) and, when seeking nectar and pollen, they invariably touched anthers and stigmas. The pollen load presented 100% of B. napus pollen. The bees' attendance to a small number of flowers/plants, their short permanence on flowers, their contact with anthers and stigma and the integral floral constancy allows their consideration as potential B. napus pollinators.


1996 ◽  
Vol 128 (3) ◽  
pp. 355-366 ◽  
Author(s):  
Carlos F. Greco ◽  
Dean Holland ◽  
Peter G. Kevan

AbstractThe foraging behaviour of honey bees (Apis mellifera L.) on inflorescences of staghorn sumac [Rhus hirta Sudworth (ex-typhina L.)] was studied using a “choice table” placed in natural stands of this plant. The choice table consisted of a wooden grid with alternated male and female inflorescences of sumac. Honey bee activity was recorded also on inflorescences of naturally growing plants in which the secretion of nectar was measured and the anther dehiscence recorded. Honey bees were the only common pollinators observed on sumac in the study area. During the morning, both plant sexes secreted little nectar, and pollen was available after the dehiscence of the anthers which took place between 1000 and 1100 hours. Female inflorescences secreted great amounts of nectar during the afternoon, but in male inflorescences there was little secretion. Honey bees seemed to forage according to the circadian availability of resources. Most of their activity concentrated on male inflorescences in the morning and on female ones during the afternoon. Both the occurrence of bees with pollen loads in their corbiculae and the length of the visits to each sex also seemed to be in accordance to the kind of resource exploited at particular times of the day. Most of the bees with pollen loads were observed during the morning and the longest visits to any inflorescences were registered on female ones during the afternoon (by bees foraging for nectar). Despite our results suggesting that the pollination success of staghorn sumac would be impaired by the foraging pattern of honey bees, an explanation is proposed for its reproductive success.


2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.


2020 ◽  
Vol 64 (1) ◽  
pp. 55-66
Author(s):  
Fiorella G. De Piano ◽  
Matias D. Maggi ◽  
Facundo R. Meroi Arceitto ◽  
Marcela C. Audisio ◽  
Martín Eguaras ◽  
...  

AbstractApis mellifera L. is an essential pollinator that is currently being affected by several stressors that disturb their ecological function and produce colony losses. Colonies are being seriously affected by the ectoparasitic mite Varroa destructor. The relationship between stressors and bee symbionts is being studied in order to enhance bee health. The goal of this study was to evaluate the effect of cell-free supernatants (CFSs) produced by Lactobacillus johnsonii AJ5, Enterococcus faecium SM21 and Bacillus subtilis subsp. subtilis Mori2 on A. mellifera nutritional parameters and their toxicity against V. destructor. Toxicity and survival bioassays were conducted on adult bees with different concentrations of CFSs. Nutritional parameters such as soluble proteins and fat bodies in abdomens were measured. Varroa destructor toxicity was analyzed by a contact exposure method and via bee hemolymph. At low concentrations, two of CFSs tends to enhance bee survival. Remarkably fat bodies maintained their levels with all CFS concentrations in the abdomens, and soluble protein increased at a high concentration of two CFSs. Toxicity against V. destructor was observed only via hemolymph, and results were in agreement with the treatment that produced an increase in bee proteins. Finally, CFS produced by L. johnsonii AJ5 could be a promising natural alternative for strengthening bee health.


2018 ◽  
Vol 19 (9) ◽  
pp. 2480 ◽  
Author(s):  
Hernán Salinas-Grenet ◽  
Ariel Herrera-Vásquez ◽  
Samuel Parra ◽  
Allan Cortez ◽  
Lilian Gutiérrez ◽  
...  

Auxin regulates diverse aspects of flower development in plants, such as differentiation of the apical meristem, elongation of the stamen, and maturation of anthers and pollen. It is known that auxin accumulates in pollen, but little information regarding the biological relevance of auxin in this tissue at different times of development is available. In this work, we manipulated the amount of free auxin specifically in developing pollen, using transgenic Arabidopsis lines that express the bacterial indole-3-acetic acid-lysine synthetase (iaaL) gene driven by a collection of pollen-specific promoters. The iaaL gene codes for an indole-3-acetic acid-lysine synthetase that catalyzes the conversion of free auxin into inactive indole-3-acetyl-l-lysine. The transgenic lines showed several abnormalities, including the absence of short stamina, a diminished seed set, aberrant pollen tubes, and perturbations in the synchronization of anther dehiscence and stamina development. This article describes the importance of auxin accumulation in pollen and its role in stamina and anther development.


Author(s):  
M. Benhaddou ◽  
M. Ghammouri ◽  
Z. Hammouch ◽  
F. Latrache

The main originality of this work consists in investigating low cycle fatigue of cylindrical test piece with wings under imposed constraint and for the temperature 20°c, 200°c, 400°c. Based on a combination between the fatigue parameter of Jiang-Sehitoglu and the relationship of Coffin-Manson, a numerical model for the prediction of the number of cycles at break. It was found that the CuCrZr cylindrical test piece showed a reduction in fatigue life with increasing temperature.


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