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Niklas Stukenberg Niklas Ahrens Hans‐Michael Poehling 《Entomologia Experimentalis et Applicata》2018,166(2):113-123
Fungus gnats occur worldwide with more than 1 700 described species. They can cause serious damages on ornamentals, crop plants, and edible mushrooms, and are considered to be a serious pest in the last years. Bradysia difformisFrey (Diptera: Sciaridae) represents a common species in Europe. Usually, yellow sticky traps are used for monitoring and control in greenhouses and fluorescent tube‐based light traps are additionally applied for control in mushroom cultivation. The importance of such visual trapping measures for efficient monitoring or alternative control increases in biological and integrated plant protection. However, detailed color preferences of fungus gnats are mostly unknown. We studied the visual orientation of B. difformis with light‐emitting diodes (LEDs) in a broad range of peak wavelengths from 371 nm (ultraviolet, UV) to 619 nm (amber). We determined attractive wavelengths in consecutive choice experiments in daylight and darkness. Highest numbers of adult B. difformis were attracted to UV radiation (382 nm) followed by green‐yellow light (532–592 nm). The responses to UV and the green‐yellow range were relatively unspecific and mostly independent from intensity. Combination of UV and yellow LEDs improved trapping efficacy compared to a single UV or yellow LED trap, as well as compared to a common yellow sticky trap. When both wavelengths were compared to a black surface to increase contrasts, the black surface was preferred over yellow, but was less attractive than UV. Thus, B. difformis displays two, probably wavelength‐specific, behaviors to UV radiation and green‐yellow light, with UV being the most attractive stimulus. These behaviors might be directly related to underlying photoreceptors, suggesting dichromatic vision in B. difformis. 相似文献
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This study developed a lighting system that produces an approximate spectral irradiance (SI) of ground level sunlight in the wavelength range of 385–910 nm (GLS385–910) using 547 light‐emitting diodes (LEDs) with 32 different peak wavelengths. The produced SI can be modified over an arbitrary wavelength band. The SI at the light outlet reached up to 1/2 of the GLS385–910 of a sunny April day, although the produced SI deviated from the GLS385–910 at some wavelengths. For subsequent experiments, the reference SI was defined as 1/4 GLS385–910 of a sunny April day. The SI produced from the lighting system was adjusted to approximate the reference SI. The ratios of the produced SI and the reference SI were within 0.72–1.28. As an application of the lighting system for biological studies, the transmitted SI of a green leaf of perilla (Perilla frutescens L.) was investigated. The curve shape of the transmitted SI, which had characteristically low transmission percentages of blue and red light, reflected the characteristics of the absorption spectra of chlorophylls. The lighting system is therefore potentially beneficial for use in diagnosing physiological conditions of plant leaves, although its application is not limited to plant physiological studies. Bioelectromagnetics 32:243–252, 2011. © 2010 Wiley‐Liss, Inc. 相似文献
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J. Li K. Hirota H. Yumoto T. Matsuo Y. Miyake T. Ichikawa 《Journal of applied microbiology》2010,109(6):2183-2190
Aims: The major objective of the study was to evaluate the enhanced germicidal effects of low‐frequency pulsed ultraviolet A (UVA)‐light‐emitting diode (LED) on biofilms. Methods and Results: The germicidal effects of UVA‐LED irradiation (365 nm, 0·28 mW cm?2, in pulsed or continuous mode) on Candida albicans or Escherichia coli biofilms were evaluated by determining colony‐forming units. The morphological change of microbial cells in biofilms was observed using scanning electron microscopy. After 5‐min irradiation, over 90% of viable micro‐organisms in biofilms had been killed, and pulsed irradiation (1–1000 Hz) had significantly greater germicidal ability than continuous irradiation. Pulsed irradiation (100 Hz, 60 min) almost completely killed micro‐organisms in biofilm (>99·9%), and 20‐min irradiation greatly damaged both microbial species. Interestingly, few hyphae were found in irradiated Candida biofilms. Moreover, mannitol treatment, a scavenger of hydroxyl radicals (OH?), significantly protected viable micro‐organisms in biofilms from UVA‐LED irradiation. Conclusions: The study demonstrated that pulsed UVA‐LED irradiation has a strong germicidal effect (maximum at 100 Hz, over 5‐min irradiation) and causes the disappearance of hyphal forms of Candida. Significance and Impact of the Study: This study can assist in developing a low‐frequency pulsed UVA‐LED system to be applied to pathogenic biofilms for disinfection. 相似文献
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The specific mechanisms by which selective pressures affect individuals are often difficult to resolve. In tephritid fruit flies, males respond strongly and positively to certain plant derived chemicals. Sexual selection by female choice has been hypothesized as the mechanism driving this behaviour in certain species, as females preferentially mate with males that have fed on these chemicals. This hypothesis is, to date, based on studies of only very few species and its generality is largely untested. We tested the hypothesis on different spatial scales (small cage and seminatural field‐cage) using the monophagous fruit fly, Bactrocera cacuminata. This species is known to respond to methyl eugenol (ME), a chemical found in many plant species and one upon which previous studies have focused. Contrary to expectation, no obvious female choice was apparent in selecting ME‐fed males over unfed males as measured by the number of matings achieved over time, copulation duration, or time of copulation initiation. However, the number of matings achieved by ME‐fed males was significantly greater than unfed males 16 and 32 days after exposure to ME in small cages (but not in a field‐cage). This delayed advantage suggests that ME may not influence the pheromone system of B. cacuminata but may have other consequences, acting on some other fitness consequence (e.g., enhancement of physiology or survival) of male exposure to these chemicals. We discuss the ecological and evolutionary implications of our findings to explore alternate hypotheses to explain the patterns of response of dacine fruit flies to specific plant‐derived chemicals. 相似文献
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Visual traps like yellow sticky card traps are used for monitoring and control of the greenhouse whitefly (Trialeurodes vaporariorum). However, reflected intensity (brightness) and hence, attractiveness depend on the ambient light conditions, and the colour (wavelength) might not fit with the sensitivity of whitefly photoreceptors. The use of light emitting diodes (LEDs) is a promising approach to increase the attractiveness, specificity and adaptability of visual traps. We constructed LED‐based visual traps equipped with blue and green high‐power LEDs and ultraviolet (UV) standard LEDs according to the putative spectral sensitivities of the insects' photoreceptors. In a series of small‐scale choice and no‐choice recapture experiments, the factors time of day as well as light intensity and light quality (colour) of LED traps were studied in terms of attractiveness compared to yellow traps without LEDs. Green LED traps (517 nm peak wavelength) were comparably attractive in no‐choice experiments but clearly preferred over yellow traps in all choice experiments. The time of day had a clear effect on the flight activity of the whiteflies and thereby on the trapping success. Blue LEDs (474 nm) suppressed the attractiveness of the light traps when combined with green LEDs suggesting that a yet undetected photoreceptor, sensitive for blue light, and an inhibiting interaction with the green receptor, might exist in T. vaporariorum. In choice experiments between LED traps emitting green light only or in combination with UV (368 nm), the green‐UV combination was preferred. In no‐choice night‐time experiments, UV LEDs considerably increased whitefly flight activity and efficacy of trapping. Most likely, the reason for the modifying effect of UV is the stimulating influence on flight activity. In conclusion, it seems that the use of green LEDs alone or in combination with UV LEDs could be an innovative option for improving attractiveness of visual traps. 相似文献
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Mohammad A. J. Bapary Jun‐ichiro Takano Shogo Soma Tadashi Sankai 《Cell biology international》2019,43(11):1296-1306
Light is an indispensable part of routine laboratory work in which conventional light is generally used. Light‐emitting diodes (LEDs) have come to replace conventional light, and thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from the African green monkey kidney, we assessed the possible consequences of the blue spectra of LED light in future animal experiments and proposed a potent mitigation against light‐induced damage. COS‐7 cells were exposed to blue LED light (450 nm) and the growth and deoxyribonucleic acid (DNA) damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as the light exposure time was prolonged. Reactive oxygen species (ROS) generation was also elevated in accordance to the extension of light exposure time. A comparison with dark‐maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time‐dependent manner. In turn, antioxidant treatment has been shown to improve cell growth and viability under blue LED light conditions. This indicates that antioxidants have potential against blue LED light‐induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and maximize the beneficial use of LED light in future animal experiments. 相似文献
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CHRIS R. SHORTALL ALISON MOORE EMMA SMITH MIKE J. HALL IAN P. WOIWOD RICHARD HARRINGTON 《Insect Conservation and Diversity》2009,2(4):251-260
Abstract. 1. For the first time, long‐term changes in total aerial insect biomass have been estimated for a wide area of Southern Britain. 2. Various indices of biomass were created for standardised samples from four of the Rothamsted Insect Survey 12.2 m tall suction traps for the 30 years from 1973 to 2002. 3. There was a significant decline in total biomass at Hereford but not at three other sites: Rothamsted, Starcross and Wye. 4. For the Hereford samples, many insects were identified at least to order level, some to family or species level. These samples were then used to investigate the taxa involved in the decline in biomass at Hereford. 5. The Hereford samples were dominated by large Diptera, particularly Dilophus febrilis, which showed a significant decline in abundance. 6. Changes in agricultural practice that could have contributed to the observed declines are discussed, as are potential implications for farmland birds, with suggestions for further work to investigate both cause and effect. 相似文献
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Dong Young Kim Jisu Kang Song Eun Lee Young Kwan Kim Seung Soo Yoon 《Luminescence》2017,32(7):1180-1185
Two blue emitters based on fluorene‐bridged quinazoline and quinoxaline derivatives were prepared via the Suzuki reaction. Their photoluminescent properties were investigated. Furthermore, theoretical studies on these materials using the density functional theory calculation were conducted. To explore their electroluminescent properties, multilayered organic light‐emitting diodes were fabricated with the following device structure: indium–tin–oxide (180 nm)/4,4′‐bis(N‐(1‐naphthyl)‐N‐phenylamino)biphenyl (50 nm)/blue emitting materials ( 1 and 2 ) (30 nm)/bathophenanthroline (35 nm)/8‐hydroxy‐quinolinato lithium (2 nm)/Al (100 nm). Two devices showed efficient blue emission with the external quantum efficiencies of 1.58% and 1.30%, respectively, at 20 mA/cm2, and Commission Internationale dÉclairage coordinates of (0.18, 0.24) and (0.19, 0.27) at 6.0 V. These results suggest that the self‐aggregation properties of emitters would have considerable effects on their photoluminescent and electroluminescent properties. 相似文献
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一种基于LED灯的自适应捕虫方法 总被引：1，自引：0，他引：1
害虫对光的敏感波长是随害虫种类、 季节等因素变化而变化, 传统捕虫灯存在发光波长类型较少、 灯与灯之间独立工作不通信的问题, 会造成捕虫灯捕虫有效性低、 能源浪费等问题。为了解决单个捕虫灯发光波长的单一性和多灯独立工作问题, 本研究通过理论分析和相应的系统设计, 得出多个灯捕虫量的最大期望值, 提出了单灯的多波长性实现方法和多灯的协调工作算法。其中单灯的多波长性是基于LED灯多波长性、 低功耗性、 易于维护等性质提出的; 多灯的协调工作算法是指通过中心节点灯与各节点灯的协调通信, 使单灯可自适应控制自身发光波长, 最终使网络中大部分节点灯波长为最佳波长, 小部分节点灯为非最佳波长, 这种方法在实现捕虫高效性的同时, 可实时监测虫种类变化, 达到自适应捕虫方法的最优化。最后通过野外实地试验验证了模拟简化的自适应捕虫方法, 结果证实了本方法在技术上的可行性和高效性。由此使这种LED捕虫灯可以方便地用于山地等复杂的野外环境中, 其中多灯的联合协作工作, 使每个捕虫灯自适应的改变发光波长, 提高了此方法的捕虫效率。 相似文献
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Joanna K. Haddock Caragh G. Threlfall Bradley Law Dieter F. Hochuli 《Austral ecology》2019,44(6):1052-1064
Artificial light at night is a pervasive anthropogenic stressor for biodiversity. Many fast‐flying insectivorous bat species feed on insects that are attracted to light‐emitting ultraviolet radiation (10–400 nm). Several countries are currently focused on replacing mercury vapour lamps, which emit ultraviolet light, with more cost‐efficient light‐emitting diode (LED) lights, which emit less ultraviolet radiation. This reduction in ultraviolet light may cause declines in insect densities in cities, predatory fast‐flying bats, and some edge‐foraging and slow‐flying bats. Capitalising on a scheme to update streetlights from high ultraviolet mercury vapour to low ultraviolet LED in Sydney, Australia, we measured the activity of individual bat species, the activity of different functional groups and the bat and insect communities, before and after the change in technology. We also surveyed sites with already LED lights, sites with mercury vapour lights and unlit bushland remnants. Species adapted to foraging in cluttered vegetation, and some edge‐space foraging species, were more active in unlit bushland sites than in all lit sites and decreased in activity at lit sites after the change to LED lights. The change to LED streetlights caused a decrease in the fast‐flying Chalinolobus gouldii but not Miniopterus schreibersii oceanensis, the latter being more influenced by seasonal and environmental variables. Insect biomass was not affected by changing light types, but instead was negatively correlated with the moon's percentage illuminance. Changing streetlights to LEDs could result in a decline in some insectivorous bats in cities. This study confirms that unlit urban bushland remnants are important refuges for high bat diversity, particularly for more clutter‐adapted species and some edge‐space foraging species. Preventing light penetration into unlit bushland patches and corridors remains essential to protect the urban bat community. 相似文献
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E. B. Jang 《Journal of Applied Entomology》2011,135(6):456-466
Trapping trials were conducted in two locations on the island of Hawaii with plastic‐matrix formulations of methyl eugenol (ME) (1‐2‐dimethoxy‐4‐allylbenzene) and cuelure (CL) [4‐(p‐acetoxyphenyl)‐2‐butanone] in traps with or without a toxicant (2, 2‐dichlorovinyl dimethyl phosphate, DDVP) against wild fly populations of oriental fruit fly, Bactrocera dorsalis (Hendel) and melon fly, Bactrocera cucurbitae (Coquillett) respectively. Both 5 g disks and 10 g cones of ME and 2 g plugs of CL caught flies for >9 months which varied relative to the population fluctuations. In all of these trials a one‐way entrance design trap caught more flies than the toxicant‐baited trap. The similar‐sized entrance holes (0.70 cm) of the latter may have slowed the dispersal of the toxicant vapour, thus causing flies to be repelled or killed outside the entrance to the trap when DDVP vapour was evolving at a maximum rate. The effect decreased as the toxicant aged. One‐way entrance traps are appropriate where toxicant traps are not allowed (e.g. organic farms), present a health hazard (e.g. yards with children), or would need to be replaced more frequently than lures. The results of these studies are discussed in relation to areawide fruit fly suppression programs where large populations of these flies are persistent, as well as to detection programs in areas where fruit flies have not established. 相似文献
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María Soledad Fernández Mariela Florencia Martínez Adriana Alicia Pérez María Soledad Santini Ignacio Tomás Gould Oscar Daniel Salomón 《Journal of vector ecology》2015,40(2):373-378
The performance of two light‐emitting diode traps with white and black light for capturing phlebotomine sand flies, developed by the Argentinean Leishmaniasis Research Network (REDILA‐WL and REDILA‐BL traps), were compared with the traditional CDC incandescent light trap. Entomological data were obtained from six sand fly surveys conducted in Argentina in different environments. Data analyses were conducted for the presence and the abundance of Lutzomyia longipalpis, Migonemyia migonei, and Nyssomyia whitmani (106 sites). No differences were found in presence/absence among the three types of traps for all sand fly species (p>0.05). The collection mean of Lu. longipalpis from the REDILA‐BL didn´t differ from the CDC trap means, nor were differences seen between the REDILA‐WL and the CDC trap collection means (p>0.05), but collections were larger from the REDILA‐BL trap compared to the REDILA‐WL trap (p<0.05). For Mg. migonei and Ny. whitmani, no differences were found among the three types of traps in the number of individuals captured (p>0.05). These results suggest that both REDILA traps could be used as an alternative capture tool to the original CDC trap for surveillance of these species, and that the REDILA‐BL will also allow a comparable estimation of the abundance of these flies to the CDC light trap captures. In addition, the REDILA‐BL has better performance than the REDILA‐WL, at least for Lu. longipalpis. 相似文献
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Sung Heo Gabseok Seo Kyung Taek Cho Yonghui Lee Sanghyun Paek Sung Kim Minsu Seol Seong Heon Kim Dong‐Jin Yun Kihong Kim Jucheol Park Jaehan Lee Lorenz Lechner Thomas Rodgers Jong Won Chung Ju‐Sik Kim Dongwook Lee Suk‐Ho Choi Mohammad Khaja Nazeeruddin 《Liver Transplantation》2019,9(45)
Although 2D|3D has shown potential for application in multifunctional devices, the principle of operation for multifunction devices (SOLAR Cell‐LED: SOLED) has not yet been revealed. However, most studies have reported that the devices have only one auspicious characteristic. Here in this study the SOLED devices are monitored and investigated in a 2D|3D heterostructure with a multidimensional perovskite. It is fond that a 2D|3D heterostructure with a multidimensional perovskite interface induces carrier transmission from the interface, increasing the density of electrons and holes, and increasing their recombination. An interface‐engineered perovskite 2D|3D‐heterojunction structure is employed to realize the multifunctional photonic device in on‐chip, exhibiting overall power conversion efficiencies of photovoltaics up to 21.02% under AM1.5, and external quantum efficiency of the light‐emitting diode up to 5.13%. This novel phenomenon is attributed to carrier transfer resulting in a high carrier density and enhanced carrier recombination at the 2D|3D interface. 相似文献
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E. Gaten 《Marine and Freshwater Behaviour and Physiology》2013,45(2):169-183
In Nephrops norvegicus damage to the compound eye following exposure to excess light is not restricted to the photoreceptor layer, but is followed by morphological changes to the dioptric apparatus. Retinula cell damage results in the disruption of the cone cell processes leading to distal retraction of the crystalline tracts. The shape of the cones is also affected and there is a redistribution of the distal pigments. Within two months of exposure the reflective properties of subcorneal elements are changed and damage may be seen in the intact eye. A method based on external observations of the intact eye has been developed for quantitatively estimating the damage to the dioptric layer. The figures obtained were compared with estimates of retinula cell damage in the same eyes calculated using measurements from serially sectioned material. The estimation of ommatidial damage without recourse to sectioning should be of immediate practical benefit. 相似文献
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Triple whitlockite‐type structure‐based red phosphors Ca8MgBi1?x(PO4)7:xEu3+ (x = 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80 and 1.00) were synthesized by a conventional solid‐state reaction route and characterized by their X‐ray crystal structures. The X‐ray diffraction (XRD) patterns, Fourier transform infrared spectra, morphologies, photoluminescence spectra, UV/Vis reflectance spectra, decay times and the International Commission on Illumination (CIE) chromaticity coordinates of Ca8MgBi1?x(PO4)7:xEu3+ were analyzed. Eu‐doped Ca8MgBi(PO4)7 phosphors exhibited strong red luminescence with peaks at 616 nm due to the 5D0 → 7 F2 electric dipole transition of Eu3+ ions after excitation at 396 nm. The UV/Vis spectra indicated that the band gap of Ca8MgBi0.30(PO4)7:0.70Eu3+ is larger than that of Ca8MgBi(PO4)7. The phosphor developed in this study has great potential as a red‐light‐emitting phosphor for UV light‐emitting diodes. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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One well‐studied bacterial factor recognized by the host immune system is lipopolysaccharides (LPS) that stimulate host cells, resulting in cell inflammation. Although photobiomodulation (PBM) therapy demonstrates its potency on anti‐inflammatory activity, the complete mechanism of action in the host–bacteria interaction model is still elusive. In addition, many studies were performed regarding a distance between the light source and biological sample (non‐contact therapy) that may result in disparate reports on the efficacy of PBM therapy. Thus, it is critical to clearly understand the effect of this approach to maximize efficacy and minimize side effects. Here, a custom‐built light‐emitting diode (LED) platform that mimics near‐contact therapy is developed. The effect and mechanism of PBM therapy on epithelial cells in response to LPS is systematically investigated under various conditions (wavelength, irradiation‐time, pulse‐frequency). The data show that the irradiation of near‐infrared (NIR‐LED) significantly improves the viability of inflamed cells. It reveals that NIR‐LED inhibits the production of reactive oxygen species by regulating the Nox4‐NF‐κB pathway. Interestingly, however, high‐pulse frequency stimulus causes the collapse of the mitochondrial membrane potential (ΔΨm) of cells, resulting in cell death. These results suggest that the optimized “PBM condition” is critical to assist the healthy immune system of the host against bacterial invasion. 相似文献