Evaluation of Deutzia x carnea (Lem.) Rehd. as a food source to urban bees

This 3-year study examined the flowering phenology, to- tal floral display, nectar and pollen production as well as bee visitation to the ornamental shrub Deutzia x carnea (Lem.) Rehd. D. x carnea bloomed from early June until the middle of July. The total flower display reached 47927 flowers per plant. The number of developed flowers strongly depended on weather conditions before and during the flowering period and fluctuated significantly during the years of study. The flower of D. x carnea lived 5 days and the persistence of an inflorescence was 11 days. Nectar productivity per 10 flowers differed significantly between the years of study and ranged between 15.7 and 40.14 mg. Mean sugar content in nectar was 39.7%. The total sugar mass in nectar per 10 flowers averaged 9.91 mg (range: 3.81 – 18.91 mg). Pollen mass per 10 flowers was 16.89 mg. The estimated sugar and pollen productivity per plant was 36.8 g and 40 g, respectively. Among bees (Apoidea), honey bees were principal visitors on Deutzia flowers. The peak of daily activity of honey bees and bumblebees occurred between 11.00 and 15.00 hrs, whereas the presence of other wild bees was noted in the morning and in the late afternoon. All bees gathered mainly nectar, but pollen collectors were also noted. The mean daily visiting rate was 0.0809 visits per flower × min-1. The use of this shrub in gardens and parks should be encouraged in order to enrich food pasture for urban Apoidea. However, its cultivation is limited to areas of mild climate and adequate water supply.

Download Full-text

Flower-visitors, nectar production, and inflorescence size of Asclepias syriaca

Canadian Journal of Botany ◽

10.1139/b79-172 ◽

1979 ◽

Vol 57 (12) ◽

pp. 1380-1388 ◽

Cited By ~ 58

Author(s):

M. F. Willson ◽

R. I. Bertin

Keyword(s):

Honey Bees ◽

Native Species ◽

Flowering Phenology ◽

Spatial And Temporal Variation ◽

Floral Display ◽

Asclepias Syriaca ◽

Nectar Production ◽

Inflorescence Size ◽

Visitation Rates ◽

The Common

Spatial and temporal variation in insect visitation rates are analyzed with respect to nectar production and inflorescence size of Asclepias syriaca L., the common milkweed. Nectar sugar production peaked in the afternoon and evening but this trend was not paralleled by visitations of native insects (either vectors or thieves). The main pollinia vectors were noctuid moths at night and honey bees (Apis mellifera) in the afternoon. Vector visitation rates were highest at the beginning (native species) or middle (total vectors) of the blooming season, declining markedly toward the end, probably as a result of decreasing frequencies of A. syriaca flowers. Large inflorescences attracted more vectors and more thieves and a higher proportion of all visits were made by vectors but the species composition of visitors did not usually change with inflorescence size. We discuss the possibility that honey bees may provide major 'new' selection pressures on floral display, nectar production patterns, and flowering phenology in the common milkweed.

Download Full-text

Effects of different fertilization practices on the glucose, fructose, sucrose, taste and texture of carrot

Agricultural and Food Science ◽

10.23986/afsci.72359 ◽

1989 ◽

Vol 61 (2) ◽

pp. 113-122

Author(s):

Aino-Maija Evers

Keyword(s):

High Performance ◽

Field Experiments ◽

Sugar Content ◽

Weather Conditions ◽

Total Sugar ◽

Sucrose Content ◽

Glucose Content ◽

Total Sugar Content ◽

Contrast Analysis ◽

The Mean

The effects of different fertilization practices on the glucose, fructose, sucrose, taste and texture of carrot cv. Nantes Duke Notabene 370 Sv were studied in field experiments carried out in southern Finland in 1985 and 1986. The effects of unirrigated and irrigated placement and broadcast fertilization, NPK fertirrigations without basic fertilization, NPK fertirrigations with NPK basic fertilization, and PK placement with N fertirrigations were compared. Further, the effects of single application were compared with those of split applications. Sugar analyses were made by high performance liquid chromatography, and sensory evaluations were performed for taste and texture. The results were analysed by contrast analysis. In 1985, fertilization and fertilization practices had no effects on sugar contents. In 1986, the unfertilized treatments had a tendency to yield higher glucose and fructose, and thus also total sugar contents than did the fertilized treatments on the average. Placement fertilization had a tendency to increase the glucose content as compared to NPK fertirrigations. No significant differences or tendencies were found in sucrose content. The glucose and fructose contents were higher in 1985 than in 1986. The sucrose content was mainly opposite, being higher in 1986.Weather conditions were more favourable for photosynthesis in 1986 than in 1985. The mean total sugar content in fresh weight was 7.8 % in 1985 and 6.7 % in 1986. Indicative results of taste and texture are presented. The sugar content in organically cultivated carrots did not differ from that of conventionally grown carrots, but the taste was worse.

Download Full-text

Flowering biology, nectar production and insect visits in Cucurbita pepo L. flowers

Acta Agrobotanica ◽

10.5586/aa.2006.019 ◽

2012 ◽

Vol 59 (1) ◽

pp. 183-197

Author(s):

Marta Dmitruk

Keyword(s):

Honey Bees ◽

Cucurbita Pepo ◽

Sugar Content ◽

Nectar Production ◽

The Mean ◽

Male Flowers ◽

Female Flowers

In 1998-2000 studies on length and abundance of flowering and on nectar productivity of zucchini and marrow (Cucurbita pepo L.) were carried out in Lublin area. Flowers visitors were also monitored. Flowering of plants lasted from the end of June till the end of September. The mean number of flowers per plant of zucchini reached: 31 (male flowers) and 26 (female flowers), and for marrow 226 and 22, respectively. Flowers lived, on average, for 5 hours. Female flowers of marrow secreted the highest amount of nectar - 1.354 g per 10 flowers, on average. Sugar content in nectar was 21.84%-27.31%. The mean total amount of sugars secreted by 10 flowers of Cucurbita pepo L. was 21.5-304.3 mg. Pollinators were mainly bumblebees and honey bees.

Download Full-text

Floral phenology, floral rewards and insect visitation in an ornamental species Geranium platypetalum Fisch. and C. A. Mey., Geraniaceae

Acta Agrobotanica ◽

10.5586/aa.2012.055 ◽

2012 ◽

Vol 65 (2) ◽

pp. 23-36 ◽

Cited By ~ 3

Author(s):

Marzena Masierowska

Keyword(s):

Sugar Content ◽

Total Sugar ◽

Skewed Distribution ◽

Floral Display ◽

Flowering Pattern ◽

Flowering Season ◽

Floral Phenology ◽

Insect Visitation ◽

The Mean ◽

Ornamental Species

This 4-year study examined the flowering pattern, floral display, nectar and pollen production as well as insect visitation to a perennial Geranium platypetalum Fisch. and C. A. Mey. G. platypetalum bloomed from the end of May until the end of June. The pattern of flowering shows the skewed distribution with a tendency towards a more symmetrical curve. The flower display size fluctuated during the flowering season. The most intense blooming fell in the 2nd and 3rd flowering week. The flowers exhibit incomplete protandry. Nectar productivity differed significantly between and stage of flower development. Ten and flowers secreted 29.8 mg and 17.6 mg of nectar, on average, respectively, with mean sugar content of 33.9% and 43.1%. The mean total sugar mass in nectar was similar for both stages and the values were 10.2 mg and 8.2 mg, respectively. Pollen mass per 10 flowers was 19.06 mg. Bees (Apoidea) were the principal visitors on Geranium flowers. The peak of daily activity of visitors occurred between 10.00 and 14.00 hrs. The insects gathered mainly nectar. The mean visiting rate was 0.149 visit per flower×min-1. Increased use of G. platypetalum in parks and gardens is recommended in order to enrich the nectar pasture for A. mellifera and wild Apoidea.

Download Full-text

Landscape structure affects the sunflower visiting frequency of insect pollinators

Scientific Reports ◽

10.1038/s41598-021-87650-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Károly Lajos ◽

Ferenc Samu ◽

Áron Domonkos Bihaly ◽

Dávid Fülöp ◽

Miklós Sárospataki

Keyword(s):

Landscape Structure ◽

Honey Bees ◽

Agricultural Landscape ◽

Edge Density ◽

Wild Bees ◽

Natural Habitats ◽

Mass Flowering ◽

Positive Effects ◽

Pollinator Community ◽

Foraging Ranges

AbstractMass-flowering crop monocultures, like sunflower, cannot harbour a permanent pollinator community. Their pollination is best secured if both managed honey bees and wild pollinators are present in the agricultural landscape. Semi-natural habitats are known to be the main foraging and nesting areas of wild pollinators, thus benefiting their populations, whereas crops flowering simultaneously may competitively dilute pollinator densities. In our study we asked how landscape structure affects major pollinator groups’ visiting frequency on 36 focal sunflower fields, hypothesising that herbaceous semi-natural (hSNH) and sunflower patches in the landscape neighbourhood will have a scale-dependent effect. We found that an increasing area and/or dispersion of hSNH areas enhanced the visitation of all pollinator groups. These positive effects were scale-dependent and corresponded well with the foraging ranges of the observed bee pollinators. In contrast, an increasing edge density of neighbouring sunflower fields resulted in considerably lower visiting frequencies of wild bees. Our results clearly indicate that the pollination of sunflower is dependent on the composition and configuration of the agricultural landscape. We conclude that an optimization of the pollination can be achieved if sufficient amount of hSNH areas with good dispersion are provided and mass flowering crops do not over-dominate the agricultural landscape.

Download Full-text

Potential Fertilization Capacity of Two Grapevine Varieties: Effects on Agricultural Production in Designation of Origin Areas in the Northwestern Iberian Peninsula

Agronomy ◽

10.3390/agronomy10070961 ◽

2020 ◽

Vol 10 (7) ◽

pp. 961

Author(s):

J. Antonio Cortiñas Rodríguez ◽

María Fernández-González ◽

Estefanía González-Fernández ◽

Rosa A. Vázquez-Ruiz ◽

F. Javier Rodríguez-Rajo ◽

...

Keyword(s):

Airborne Pollen ◽

Germination Rate ◽

Pollen Viability ◽

Weather Conditions ◽

Triphenyl Tetrazolium Chloride ◽

Tetrazolium Chloride ◽

The Mean ◽

Study Sites ◽

Fertilization Capacity

In the present study, we analyzed the main parameters related with the potential fertilization ability of two grapevine varieties, Godello and Mencía, during the years 2017 and 2018. The research was carried out in two vineyards of the Galician winegrowing Designation of Origin areas of Ribeiro and Ribeira Sacra. Ten vines of each variety were selected for bunch and flower counting, pollen calculations, pollen viability studies by means of aceto-carmine (AC) stain and 2, 3, 5-triphenyl tetrazolium chloride (TTC) methods, and the determination of their germination rate. In all vineyards the 50% fruitset was reached, except for Godello in Cenlle during 2017. The mean coulure value was higher for Godello (40.5%) than for Mencía (31%). Analyzing the pollen production per plant and airborne pollen levels, we observed important discordances between them, which can be due to the influence of weather conditions and be related with self-pollination processes. We found important differences on pollen viability depending on the applied method and variety, with higher values for the AC method than the TTC for both varieties in all study plots, and higher values for Mencía variety than Godello. Regarding germination rates, we observed a marked reduction in 2017 with respect to 2018, in all study sites and for both varieties. The analyzed parameters were useful to explain the different productive abilities of Godello and Mencía varieties in the two studied bioclimatic regions of Ribeiro and Ribeira Sacra.

Download Full-text

Thermoregulation in colonies of africanized and hybrids with Caucasian, Italian and Carniolan Apis mellifera honey bees

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89131999000400007 ◽

1999 ◽

Vol 42 (4) ◽

Author(s):

Vagner de Alencar Arnaut de Toledo ◽

Regina Helena Nogueira-Couto

Keyword(s):

Apis Mellifera ◽

Honey Bees ◽

Maximum Temperature ◽

Tropical Region ◽

Internal Temperature ◽

Africanized Honey Bees ◽

Significant Difference ◽

The Mean ◽

One Year ◽

Brood Nest

This experiment was carried out to study the internal temperature regulation of a colony of Africanized honey bees (AFR), compared with hybrid Caucasian (CAU), Italian (ITA), and Carniolan (CAR) bees, during the period of one year and different size hives located in a sub-tropical region. The instant internal temperature, 33.7 ± 1.5° C for the AFR, 33.5 ± 1.4° C for the CAU, 33.7 ± 1.5° C for the ITA and 33.8 ± 1.4° C for the CAR, did not show any significant difference (P>0.05). The maximum temperature (36.1 ± 2.3° C) was statistically different (P<0.05) from the minimum (27.6 ± 5.3° C). There was no difference (P>0.05) in the mean internal temperature, between the nucleus (31.7 ± 6.3° C) and the brood nest (32.1 ± 5.3° C) measured between two and four o'clock in the afternoon.

Download Full-text

Seasonal activity of Dermacentor reticulatus ticks in the era of progressive climate change in eastern Poland

Scientific Reports ◽

10.1038/s41598-021-99929-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Zbigniew Zając ◽

Joanna Kulisz ◽

Aneta Woźniak ◽

Katarzyna Bartosik ◽

Adil Khan

Keyword(s):

Climate Change ◽

Local Population ◽

Weather Conditions ◽

Dermacentor Reticulatus ◽

Seasonal Activity ◽

Saturation Deficit ◽

Annual Basis ◽

Questing Ticks ◽

The Mean

AbstractDermacentor reticulatus ticks are one of the most important vectors and reservoirs of tick-borne pathogens in Europe. Changes in the abundance and range of this species have been observed in the last decade and these ticks are collected in areas previously considered tick-free. This may be influenced by progressive climate change. Eastern Poland is an area where the local population of D. reticulatus is one of the most numerous among those described so far. At the same time, the region is characterized by a significant increase in the mean air temperature in recent years (by 1.81 °C in 2020) and a decrease in the average number of days with snow cover (by 64 days in 2020) and in the number of days with frost (by 20 days in 2020) on an annual basis compared to the long-term average. The aim of our research was to investigate the rhythms of seasonal activity and the population size of D. reticulatus in the era of progressive climate change. To this end, questing ticks were collected in 2017–2020. Next, the weather conditions in the years of observation were analyzed and compared with multi-year data covering 30 years preceding the study. The research results show that, in eastern Poland, there is a stable population of D. reticulatus with the peak of activity in spring or autumn (up to a maximum of 359 individuals within 30 min of collection) depending on the year of observation. Ticks of this species may also be active in winter months. The activity of D. reticulatus is influenced by a saturation deficit.

Download Full-text

A Behavioral Model of Drivers’ Mean Speed Influenced by Weather Conditions, Road Geometry, and Driver Characteristics Using a Driving Simulator Study

Advances in Civil Engineering ◽

10.1155/2021/5542905 ◽

2021 ◽

Vol 2021 ◽

pp. 1-18

Author(s):

Mehdi Zolali ◽

Babak Mirbaha ◽

Maziyar Layegh ◽

Hamid Reza Behnood

Keyword(s):

Latent Variables ◽

Latent Variable ◽

Structural Equation ◽

Driving Simulator ◽

Weather Conditions ◽

Geometric Design ◽

Equation Modeling ◽

Novice Drivers ◽

Sight Distance ◽

The Mean

Driving above the speed limit is one of the factors that significantly affect safety. Many studies examined the factors affecting the speed of vehicles in the simulated environment. The present study aimed to analyze drivers’ characteristics, time and weather conditions, and geometric features’ effect on mean speed in simulated conditions simultaneously. In this regard, the simulator experiment data of 70 drivers were collected in a two-lane rural highway at six different times, and weather scenarios and their socioeconomic characteristics were collected by a questionnaire. Structural equation modeling (SEM) was used to capture the complex relationships among related variables. Eleven variables were grouped into four latent variables in the structural model. Latent variables including “Novice Drivers,” “Experienced Drivers,” “Sight Distance,” and “Geometric Design” were defined and found significant on their mean speed. The results showed that “Novice Drivers” have a positive correlation with the mean speed. Meanwhile, “Experienced Drivers,” who drive 12% slower than the novice group, negatively affect the mean speed with a standard regression weight of −0.08. This relation means that young and novice drivers are more inclined to choose higher speeds. Among variables, the latent variable “Sight Distance” has the most significant effect on the mean speed. This model shows that foggy weather conditions strongly affect the speed selection behavior and reduce the mean speed by 40%. Nighttime also reduces mean speed due to poor visibility conditions. Furthermore, “Geometric design” as the latent variable indicates the presence of curves on the simulated road, and it can be concluded that the existence of a curve on the road encourages drivers to slow down, even young drivers. It is noteworthy that the parts of the simulated road with a horizontal curve act as a speed reduction tool for drivers.

Download Full-text

Sugar accumulation in winter wheat crops depending on the sowing dates

Siberian Herald of Agricultural Science ◽

10.26898/0370-8799-2019-2-3 ◽

2019 ◽

Vol 49 (2) ◽

pp. 27-33

Author(s):

S. I. Anosov ◽

A. S. Surnachev ◽

K. K. Musinov

Keyword(s):

Winter Wheat ◽

Coefficient Of Variation ◽

Sugar Content ◽

Weather Conditions ◽

Sugar Accumulation ◽

Planting Dates ◽

Air Temperatures ◽

Sowing Dates ◽

Soft Winter Wheat ◽

Growing Conditions

The object of the research was to study the influence of sowing dates on sugar accumulation in different varieties of soft winter wheat. Less winterhardy variety of soft winter wheat Novosibirskaya 2 was compared with more winter-hardy ones Novosibirskaya 3, Novosibirskaya 40 and Krasnoobskaya ozimaya. The research was carried out in 2016-2018 inthe established experimental plot in the foreststeppe of Priobye, theObregion. The predecessor was bare fallow. The planting dates were August 20, September 1, September 10. Weather conditions of the autumn growing season, during which the accumulation of sugars occurs, differed significantly depending on the year of study and the sowing dates. The warmest conditions were in 2018, whereas the coolest – in 2017. The amount of accumulated sugars varied depending on the growing conditions and genotypic characteristics of varieties. The highest amount of sugars was accumulated by all varieties during the third term of planting, the lowest amount – during the second term. Lower air temperatures contributed to the increase in the amount of sugars, even when the duration of their accumulation period was shortened, which can be explained by a change in carbohydrate balance in crops when the accumulation of sugars is greater than their consumption for crop respiration. The genotype plays an important role in the carbohydrate metabolism of plants. In more winter-hardy varieties (Novosibirskaya 40, Novosibirskaya 3), the change in the amount of accumulated sugars in contrasting conditions ranged insignificantly (the coefficient of variation was 9.1 and 8.7%, respectively). At the same time, plants of the less winter-hardy variety of Novosibirskaya 2 showed a significantly greater variation in the sugar content under similar conditions (the coefficient of variation 24.7%). Cooler conditions of a later term of sowing contributed to the greatest amount of accumulated sugars. Varietal differences also determined changes in carbohydrate balance.

Download Full-text