scholarly journals Foraging behavior of Melipona rufiventris Lepeletier (Apinae; Meliponini) in Ubatuba, SP, Brazil

2007 ◽  
Vol 67 (1) ◽  
pp. 133-140 ◽  
Author(s):  
AO. Fidalgo ◽  
AMP. Kleinert

This study describes how the foraging activity of Melipona rufiventris is influenced by the environment and/or by the state of a colony. Two colonies were studied in Ubatuba, SP (44° 48’ W and 23° 22’ S) from July/2000 to June/2001. These colonies were classified as strong (Colony 1) and intermediate (Colony 2) according to their general conditions: population and brood comb size and number of food pots. The bees were active from dawn to dusk. The number of pollen loads presented a positive correlation with relative humidity (r s = 0.401; p <0.01) and was highest between 70 and 90%. However, it was negatively correlated with temperature (r s = -0.228; p <0.01) showing a peak between 18 and 23 °C. The number of nectar loads presented a positive correlation with temperature (r s = 0.244; p <0.01) and light intensity (r s = 0.414; p <0.01); it was greater between 50 and 90% of relative humidity and 20 and 30 °C of temperature. They collected more nectar than pollen throughout the day, and were more active between 6 and 9 hours. Workers from Colony 1 (strong) collected nectar in greater amounts and earlier than those from Colony 2 (intermediate). The number of pollen, nectar and resin loads varied considerably between the study days. Peaks of pollen collection occurred earlier in months with longer days and in a hotter and more humid climate. The foraging behavior of M. rufiventris is probably affected by the state of the colony and by environmental conditions, notably temperature, relative humidity, light intensity and length of the day.

2021 ◽  
Vol 21 (1) ◽  
pp. 12-17
Author(s):  
MALAY K. SAMANTA ◽  
PRANAB HAZRA

A study was undertaken for two consecutive seasons (autumn-winter) to evaluate the performance of three green, red and yellow-fruited sweet pepper hybrids in open field and under two protected structures (50% green shade net house and naturally-ventilated polyhouse) to understand the microclimate suitability for maximizing the productivity of these hybrids under sub-tropical humid climatic condition of eastern India. In this climatic condition, naturally-ventilated polyhouse was most suitable for enhancing fruit yieldof both green and coloured fruited hybrids. Open field condition was not suitable for both yellow and redfruited hybrids. Though green-fruited hybrids could be grown in open field condition, fruit yield was more than double under polyhouse. Shade net house could not be considered as a suitable protected structure for sweet pepper in this climatic condition because of reduced light intensity and high relative humidity inside it causing low fruit set and high incidence of bacterial wilt disease. Maximum/minimum temperature30oC to 33oC / 14oC to 17oC with comparatively reduced light intensity of 35,000 to 55,000 lux, prevention of adverse effect of low night temperature during winter and  60 per cent relative humidity condition during flowering, fruit set and fruit development period inside the naturally ventilated polyhouse were most suitable growing conditions for getting maximum productivity of both green and colour-fruited hybrids of sweet pepper.


Author(s):  
Guotao Yang ◽  
Xuechun Wang ◽  
Farhan Nabi ◽  
Hongni Wang ◽  
Changkun Zhao ◽  
...  

AbstractThe architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lijun Cheng ◽  
Yong Kang ◽  
Guishui Li

Difference between adsorption of benzene by diatomite and nano-TiO2immobilized on diatomite was investigated. And effects of temperature, light intensity, relative humidity, and initial benzene concentration on adsorption and degradation of benzene by nano-TiO2immobilized on diatomite were also studied. The experimental results showed that when initial benzene concentration was2.2×10−3 mg L−1, it could be degraded to below safe concentration (1.1×10−4 mg L−1) after 50 h when temperature was 20°C, but it just needed 30 h at 35°C. When light intensity was 6750 Lx, it needed 30 h for benzene to be degraded to below safe concentration, but benzene could barely be degraded without light. When relative humidity was 50%, benzene could be degraded to1.0×10−4 mg L−1after 30 h, while its concentration could be reduced to7.0×10−5 mg L−1at the relative humidity of 80%.


2004 ◽  
Vol 82 (12) ◽  
pp. 1910-1916 ◽  
Author(s):  
Sue Lewis ◽  
Silvano Benvenuti ◽  
Francis Daunt ◽  
Sarah Wanless ◽  
Luigi Dall'Antonia ◽  
...  

Many species of seabirds are known to undertake foraging trips that vary in duration, lasting from a few hours up to several days. However, the important question of how individuals allocate their time during foraging trips of different durations has received relatively little attention until recently. Using activity loggers, we examined the foraging behavior of chick-rearing northern gannets, Morus bassanus (L., 1758), during trips of different durations, and tested predictions concerning how foraging activity varies across trips. There was no evidence of a relationship between dive frequency during the first 3 h of a trip and trip duration, suggesting that the decision to continue on a longer trip was not affected by an adult's initial rate of encounter with prey. Flight constituted approximately 50% of total trip time, and the dive rate of birds per daylight hour was apparently unaffected by trip duration. Birds dived at similar rates on the outward and return sections of their foraging trips, which suggests that they may have been "topping up" on food on their return. Overall our results suggest that, unlike other pelagic seabirds, northern gannets at the Bass Rock do not adjust their individual foraging strategies among trips of different durations.


2010 ◽  
Vol 26 (3) ◽  
pp. 351-354 ◽  
Author(s):  
Eric J. Fuchs ◽  
Jeffrey Ross-Ibarra ◽  
Gilbert Barrantes

The reproductive success of hummingbird-pollinated plants often depends on complex interactions between environmental conditions and pollinator biology (Navarro 1999, Stiles 1985, Wolf et al. 1976). The effect of environment on reproductive success of hummingbird-pollinated plants is particularly pronounced at high altitudes, where large daily fluctuations in temperature, relative humidity and solar radiation limit the effective time for photosynthesis (Cavieres et al. 2000) and affect foraging activity (Navarro 1999) and abundance of pollinators (Rahbek 1997). At high altitudes in the tropical cloud forests of Costa Rica these factors may have serious impacts on fruit production.


2017 ◽  
Vol 114 (37) ◽  
pp. 9797-9802 ◽  
Author(s):  
Jörn Heine ◽  
Matthias Reuss ◽  
Benjamin Harke ◽  
Elisa D’Este ◽  
Steffen J. Sahl ◽  
...  

The concepts called STED/RESOLFT superresolve features by a light-driven transfer of closely packed molecules between two different states, typically a nonfluorescent “off” state and a fluorescent “on” state at well-defined coordinates on subdiffraction scales. For this, the applied light intensity must be sufficient to guarantee the state difference for molecules spaced at the resolution sought. Relatively high intensities have therefore been applied throughout the imaging to obtain the highest resolutions. At regions where features are far enough apart that molecules could be separated with lower intensity, the excess intensity just adds to photobleaching. Here, we introduce DyMIN (standing for Dynamic Intensity Minimum) scanning, generalizing and expanding on earlier concepts of RESCue and MINFIELD to reduce sample exposure. The principle of DyMIN is that it only uses as much on/off-switching light as needed to image at the desired resolution. Fluorescence can be recorded at those positions where fluorophores are found within a subresolution neighborhood. By tuning the intensity (and thus resolution) during the acquisition of each pixel/voxel, we match the size of this neighborhood to the structures being imaged. DyMIN is shown to lower the dose of STED light on the scanned region up to ∼20-fold under common biological imaging conditions, and >100-fold for sparser 2D and 3D samples. The bleaching reduction can be converted into accordingly brighter images at <30-nm resolution.


2018 ◽  
Vol 15 (2) ◽  
pp. 207-214
Author(s):  
I Hossain ◽  
MMH Khan ◽  
SMH Jahan

The study was conducted to know the reproductive performance of spiralling whitefly on guava. Number of colony, eggs, 1st instar, 2nd instar, 3rd instar and 4th instar nymphs per five leaves ranged from 6 to 15, 8 to 32, 0 to 44, 0 to 22, 0 to 45 and 0 to 28, respectively. Maximum number of adults and nymphs were found in the month of January. Highest longevity of Aleurodicus dispersus (21.5 days) was recorded in adult while the lowest was in 2nd instar nymph (6.4 days). The number of colony/leaf and number of 3rd and 4th instar nymphs of A. dispersus had significant positive correlation with minimum and maximum temperature while non-significant positive correlation is observed between the number of egg/colony, the number 1st and 2nd instar nymphs with minimum and maximum temperature. A. dispersus showed nonsignificant positive correlation with minimum and maximum relative humidity regarding number of colony/leaf, 2nd instar nymph while nonsignificant negative correlation with 4th instar nymph.SAARC J. Agri., 15(2): 207-214 (2017)


2017 ◽  
Vol 9 (2) ◽  
pp. 1208-1213
Author(s):  
Lalita Lalita ◽  
Yogesh Kumar

Foraging activity period of different honey bee species on C. moschata (C-1076) flowers at different day hours during August-September (2013) revealed that A. dorsata, A. mellifera, A. cerana and A. florea initiated their activity early in the morning at 0530, 0615, 0625 and 0630 h, respectively and stopped their activity at 1030, 1020, 1025 and 1030 h of the day, respectively while on C. moschata (C-1106, A. dorsata, A. mellifera, A. cerana and A. florea initiated their activity early in the morning at 0535, 0615, 0620 and 0625 h, respectively and ceased their activity at 1045, 1025, 1015 and 1040 h of the day, respectively. The mean foraging speed (time spent per flower) in seconds on flowers of pumpkin (C-1106) was maximum of A. florea (181.72), followed by A. mellifera (7.15), A. cerana (6.05) and A. dorsata spent least time (5.83) and in pumpkin (C-1076), foraging speed was maximum in case of A. florea (178.71), followed by A. mellifera (7.63), A. cerana (6.24) and A. dorsata spent least time (6.06). The mean foraging rate (flowers visited per minute) on flowers of pumpkin (C-1106) was maximum in case of A. dorsata (5.13), followed by A. cerana (4.30), A. mellifera (4.16) and A. florea visited least flower (0.32) and in pumpkin (C-1076), foraging rate was maximum in case of A. dorsata (4.96), followed by A. cerana (4.19), A. mellifera (4.02) and A. florea visited least flower (0.33). Present study advises the farmers that they should not apply the pesticide when the activityof honey bee is on the peak period because pesticides application at the time of bee activity in the field crop causes mortality of bees.


2017 ◽  
Vol 9 (3) ◽  
pp. 1603-1607
Author(s):  
Lalita Lalita ◽  
Yogesh Kumar

Foraging activity period of different honey bee species on C. moschata (C-1076) flowers at different day hours during August-September (2013) revealed that A. dorsata, A. mellifera, A. cerana and A. florea initiated their activity early in the morning at 0530, 0615, 0625 and 0630 h, respectively and stopped their activity at 1030, 1020, 1025 and 1030 h of the day, respectively while on C. moschata (C-1106, A. dorsata, A. mellifera, A. cerana and A. florea initiated their activity early in the morning at 0535, 0615, 0620 and 0625 h, respectively and ceased their activity at 1045, 1025, 1015 and 1040 h of the day, respectively. The mean foraging speed (time spent per flower) in seconds on flowers of pumpkin (C-1106) was maximum of A. florea (181.72), followed by A. mellifera (7.15), A. cerana (6.05) and A. dorsata spent least time (5.83) and in pumpkin (C-1076), foraging speed was maximum in case of A. florea (178.71), followed by A. mellifera (7.63), A. cerana (6.24) and A. dorsata spent least time (6.06). The mean foraging rate (flowers visited per minute) on flowers of pumpkin (C-1106) was maximum in case of A. dorsata (5.13), followed by A. cerana (4.30), A. mellifera (4.16) and A. florea visited least flower (0.32) and in pumpkin (C-1076), foraging rate was maximum in case of A. dorsata (4.96), followed by A. cerana (4.19), A. mellifera (4.02) and A. florea visited least flower (0.33). Present study advises the farmers that they should not apply the pesticide when the activity of honey bee is on the peak period because pesticides application at the time of bee activity in the field crop causes mortality of bees.


2016 ◽  
Vol 10 ◽  
pp. 44-53 ◽  
Author(s):  
Daniela Silvana Nitiu ◽  
Andrea Mallo ◽  
Mario Saparrat ◽  
Mauro Garcia Santa Cruz

The aim of the present study was to assess the state of conservation of the fossilized skin fragment assigned to Mylodon listai preserved in a showcase of the Paleontology Hall of the Museum of La Plata. To this end, we conducted a volumetric aerobiological sampling both inside the showcase and in the hall to detect the presence of fungal load that could alter its preservation. We also determined the environmental parameters both inside and outside the showcase. The aerobiological sampling inside the showcase showed 3061.50 spores/m3 corresponding to 22 fungal types, while in the hall, 2283.20 spores/m3 corresponding to 14 fungal types where detected. Cladosporium was the most important type in all the sampling points. The temperatures recorded were lower than those recommended for the conservation of leather and the relative humidity values were acceptable in 70% of the record for this material


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