Trap Types Research Articles

The Effect of the Hight of the Pheromone Traps Type Delta in Trapping and Forecasting the Emergence of the Lesser Date Moth, Batrachedra amydraula Meyrick and Evaluating the Sensitivity of Some Palm Varieties to Insect Injury

El-Filahy, M.H.A. and M.Sh. Mansour. 2023. The Effect of the Hight of the Pheromone Traps Type Delta in Trapping and Forecasting the Emergence of the Lesser Date Moth, Batrachedra amydraula Meyrick and Evaluating the Sensitivity of Some Palm Varieties to Insect Injury. Arab Journal of Plant Protection, 41(3): 226-232. https://doi.org/10.22268/AJPP-41.3.226232 During the 2021-2022 season field study conducted in Anbar governorate to determine the population dynamics of Batrachedra amydraula using pheromone traps (Alpha scenes Inc. West Linn) and the effect of trap height on number of male insects traped. In addition, host preference and sensitivity of date palm varieties to infestation with the insect was also evaluated. The results obtained showed that the first appearance of the insect was at the end of the third week of March with an average of 2 insects/trap at a temperature of 16.5°C and 51.5% RH. The number of insects caught in the trap reached a peak during the first week of June at an average of 139 insect/trap, at a temperature of 32°C and 42% RH. The insect count then decreased after the third week of June to zero insects/trap until the third week of July. Field experiments also showed that the traps height had an effect on the number of insects caught. The average number of total insects caught in traps at 1.5 m was 45.5, whereas the average number of insects caught in traps placed at 2.5 m was 20.5. The results also showed that the highest total infestation rate in the Khistawi variety was 36.89%, followed by Zahdi (18.83%). The infestation rate of the variety kheyara was the lowest (12.61%). The results also showed the average larval density of the insect Batrachedra amydraula was the highest on the khestawi variety with total average injury severity of 0.14%, followed by zahdi variety with an average total injury severity of 0.05%. Therefore, by combining the infestation rate and average number of the insect larvae, it can be concluded that the Khistawi variety was the most sensitive to the insect, and the variety Kheyara was the most tolerant. In addition, the use of pheromone traps was instrumental in reducing the injury caused by the insect, and using resistant/tolerant varieties can effectively contributes to the reduction of the infestation rate of the insect to become below the economic injury level. Keywords: Date palm, Phoenix dactylifera L., Lesser date moth Batrachedra amydraula, Pheromone traps, Variety sensitivity

Use of Food Attractant to Monitor and Forecast Population Dynamics of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae), a Long-Distance Migratory Pest

The rice leaf folder, Cnaphalocrocis medinalis, is a significant migratory pest that restricts rice production in Asia and Africa, and monitoring and early warning measures are the basis for its management. Based on its regional migratory path in China, the pest population dynamics were monitored from 2020 to 2021 using food attractants. In this study, we also used internal reproductive system dissection to determine the adult age and reproductive developmental state. The monitoring results indicated that the trapping dynamics of C. medinalis males using food attractants and sex pheromones were approximately similar. Both trapping methods yielded C. medinalis males of different ages, with an identical age structure for both trap types. Dissection analysis of the reproductive system of females trapped using the food attractants indicated that in 2020, the population of C. medinalis in Liling, Hunan Province, was indigenous, while populations in other monitoring sites mainly comprised migrants from other areas. The ovarian development level of females trapped using food attractants showed a positive correlation with the age of males, and there was also a significant positive correlation between the index of ovarian development of females and the mating time. Furthermore, a dynamic prediction method for fecundity in field populations was established based on the quantity of eggs held by the females. This study provides a new method for the monitoring and early warning of the existence of C. medinalis populations.

Evaluation of trap type and attractant composition for potential mass trapping of Hylobius abietis

Abstract Different trap types and attractant compositions were tested with the goal of attracting as many individuals of Hylobius abietis as possible while assuring a minimal bycatch of nontarget species with regard to the family Carabidae on three study sites in the east of Germany. The results revealed a modified pitfall trap based on a model by Nordlander (1987, Scandinavian Journal of Forest Research, 2, 199–213.) as the most effective trap type with a high degree of selectivity and minimal ecological side effects. The modified Nordlander trap is suitable for potential H. abietis mass trapping as an instrument of integrated pest management. Two field trials testing different attractant compositions showed that a simple attractant combination of (−)‐α‐pinene and ethanol is as effective as other more complex combinations and thus preferable for mass trapping efforts. The addition of the monoterpenes camphene, Δ‐3‐carene, ocimene and terpinolene to the combination of (−)‐α‐pinene and ethanol did not increase trapping numbers significantly. Trapping numbers of H. abietis indicate that a reduction of the local H. abietis population by trapping is possible, though further research about the influence of mass trapping on regeneration damage is recommended.

Effect of dose and trap type on captures of striped and spotted cucumber beetles using synthetic vittatalactone.

Striped cucumber beetle, Acalymma vittatum (F.) and spotted cucumber beetle (Diabrotica undecimpunctata howardi Barber) are key pests of cucurbits. Pesticide applications directed against cucumber beetles can jeopardize bee pollination which is essential to crop yield. Alternative selective tactics, including behavioral control for managing cucumber beetles, are needed in order to improve pest management. The striped cucumber beetle pheromone vittatalactone is attractive to both male and female adults, and also to spotted cucumber beetles. We tested the response of both species to different doses of synthetic vittatalactone, and to different trap types, in field trapping experiments in Maryland. Both species showed strong dose-response in May-June and October 2020. Among 12 trap types tested during a 2-wk experiment in June, using 1 mg mixed vittatalactone, sticky panel traps caught the most of each species, with vittatalactone-baited traps exceeding unbaited traps by >8 fold for striped and >2 fold for spotted, and with significant response to yellow versus clear color absent in striped, but strong in spotted. Among nonsticky traps, those with yellow or yellow-green exceeded those without these colors for both beetle species, and a ground-placed boll weevil trap captured the most striped cucumber beetles. Bucket-style traps caught excessive nontarget bumblebees (Bombus spp.) if yellow, and a few beetles, if all green. Results allow field monitoring with a choice of sticky or nonsticky traps and suggested lure loading of 1 mg mixed vittatalactone, containing ~90 μg active isomer. These findings contribute to the development of multispecies behavioral monitoring and control as a component of cucurbit IPM.

Two sticky traps baited with synthetic host odors to capture Triatoma infestans, an important vector of Chagas disease

Chagas disease is a vector-borne disease caused by Trypanosoma cruzi, which is transmitted by triatomine insects. Triatoma infestans is one of the main vectors. Efforts to eliminate T. infestans have often failed in the Gran Chaco, the largest endemic area of this species. Known methods for assessing triatomine house infestation include timed-manual collections by skilled personnel, bug notifications by householders’ and/or non-baited detection devices. However, the detection sensitivity of those methods needs to be improved, especially when the bugs are present at low densities. In this work we design and evaluate the performance of two types of sticky traps (pitfall and climbing traps), when baited with a synthetic host odor lure, to capture T. infestans nymphs within an experimental box under semi-controlled laboratory conditions. Nine assays were conducted for each type of trap using a different experimental box per type of trap design and per treatment. These treatments were: test (T, trap baited with the synthetic lure), positive control (C+, trap baited with a mouse) and negative control (C−, empty trap). One hundred percent of the sticky pitfall and 89% of the climbing traps baited with the synthetic lure captured at least one insect. Moreover, the sticky pitfall trap and the sticky climbing trap, both baited with the synthetic lure, captured 30% and 40% of the insects in a single night, respectively. In both cases, the trap with the synthetic lure captured significantly more insects than the non-baited trap. However, the synthetic lure could be improved, as the traps with this lure captured significantly less insects than the traps with a live host. In summary, the two types of synthetically-baited traps tested were able to capture T. infestans nymphs, indicating that both designs are effective under the laboratory experimental conditions and insect abundance used in this work. These traps deserve to be tested in a field setting.

Seasonal Dynamics of the Brown Marmorated Stink Bug, Halyomorpha halys (Hemiptera: Pentatomidae), in Apple Orchards of Western Slovenia Using Two Trap Types

The invasive Halyomorpha halys is a serious pest for several fruit trees, causing millions of dollars of crop damage every year across the world’s major fruit-growing regions. Once established in an orchard, H. halys quickly becomes the predominant stink bug species and is a major season-long pest. Annual increases in the population size of H. halys have resulted in increased pest pressure and a growing risk of severe crop damage. Reliable monitoring is indispensable for H. halys control and management, providing comprehensive information on the seasonality of pest population dynamics, abundance, and interaction with the environment, and is essential for the successful implementation of integrated pest management (IPM) strategies to prevent crop damage. Our study followed the seasonal population dynamics of H. halys in three apple orchards in the Goriška region of western Slovenia over the period 2019–2021. Pherocon® Dual Panel Adhesive Traps (Trece Inc.) and pyramidal Rescue® Stink Bug Traps, both baited with Trécé lures (two-component H. halys aggregation pheromone + pheromone synergist), were used to monitor H. halys adults and nymphs weekly from late March to the end of November. Captures taken with both types of trap clearly describe the seasonal dynamics of H. halys, with the first occurrence of overwintering adults in April and May, and with two peak occurrences in adults, in the middle of summer and in the beginning of autumn, corresponding to the appearance of two generations per year in the study area. The growing trap captures observed during the 3-year monitoring period suggest that H. halys was only recently introduced to the area and that natural enemies have not yet been fully recruited. Pyramid traps captured significantly more adults and nymphs than clear sticky traps and provided accurate monitoring of H. halys life stages throughout the season. Regardless of the lower trap catches of adults and juveniles, clear sticky traps clearly displayed H. halys seasonal dynamics pattern. Therefore, their use is recommended as an early detection tool in areas where pests are not yet present, or in areas with small H. halys populations. Halyomorpha halys adult trap captures were higher in Šempeter orchards, within areas of great landscape diversity and a large share of urban land. The seasonal dynamics of H. halys over the 3-year period were closely related to weather conditions, with temperature and relative humidity as the major factors affecting population growth.

Armadilha Adultrap® otimizada para coleta de ovos, larvas e adultos de mosquitos vetores

ABSTRACT The productivity of the Adultrap® trap was compared to that of modified adultrap traps. Two structural changes were tested, a cover was placed at the entrance of the trap at two different heights. A comparison was also made with traps containing hydrogel to replace the water in the reservoir. The positivity rates of all the trap types were calculated and compared. The hydrogel models were more productive because they collected eggs, larvae, and adults. The trap that removed the protective screen and replaced the water with the hydrogel was 18.5 times larger than the original trap (p = 0.001). There was an increase in the productivity for the total collection of mosquitoes. The collection of eggs, larvae, and adults can contribute to the construction of more robust infestation indices. In addition, it allows for the collection of live specimens and the development of studies.

Towards reliable estimates of abundance trends using automated non‐lethal moth traps

Abstract Monitoring insect abundance or species richness at high spatial and temporal resolution is difficult due to personnel, maintenance, and post‐processing costs as well as ethical considerations. Non‐invasive automated insect monitoring systems could provide a solution to address these constraints. However, every new insect monitoring design needs to be evaluated with respect to reliability and bias based on comparisons with conventional methods. In this study, we evaluate the effectiveness of an automated moth trap (AMT), built from off‐the‐shelf‐hardware, in capturing declines in moth abundance, by comparing it to a conventional, lethal trap. Both trap types were operated five times on 16 plots from the beginning of July 2021 to the end of August 2021. On average AMTs recorded fewer individuals than conventional traps. However, both trap types depicted the same seasonal decline of approximately 3% per day, which corresponded to a total difference of ~85% over the sampling period. Given our sample size, both trap types had the same limitations in their reliability to detect smaller changes in abundance trends. This first proof of concept demonstrated that AMTs depict large magnitude events such as phenological patterns just as well as conventional, lethal traps. Therefore, AMTs are a promising tool for future autonomous and non‐lethal monitoring, which paves the way for high temporal coverage and resolution in insect monitoring. However, this initial quantitative field test revealed that its long‐term applicability must be preceded by several adjustments to the image quality, power supply and to data transfer.

Pan trapping is an effective method to trap adults of the jujube gall midge, Dasineura jujubifolia (Diptera: Cecidomyiidae).

Jujube gall midge (Dasineura jujubifolia Jiao & Bu) (Diptera: Cecidomyiidae) is an important pest in jujube (Ziziphus jujuba Mill.) orchards in Aksu, Xinjiang, China. Yellow sticky traps are the main device used for monitoring jujube gall midge adults, but their efficacy is low. Here, we compared the effectiveness of yellow sticky traps with water pan traps (are commonly used for trapping Diptera insects) to monitor jujube gall midge adults. Yellow sticky traps and pan traps were deployed for 2 consecutive years in jujube orchards in Aksu, Xinjiang, China. The midge's population dynamics as revealed by these 2 trap types were consistent, but the effectiveness of pan traps was about 5 times greater than that of the yellow sticky traps. In addition, pan traps captured fewer non-target species (e.g., parasitic wasps, lacewings, and lady beetles) than yellow sticky traps. Our study suggests that pan trap is an effective device to monitor jujube gall midge adults with minimal harm to natural enemies.

A data-driven approach to estimating post-discovery parameters of unexplored oilfields

Consider a typical situation where an investor is considering acquiring an unexplored oilfield. The oilfield has undergone a preliminary geological and geophysical study in which pre-discovery data such as lithology, depth, depositional system, diagenetic overprint, structural compartmentalization, and trap type are available. In this situation, investors usually estimate production rates using a volumetric approach. A more accurate estimation of production rates can be obtained using analytical methods, which require additional data such as net pay, porosity, oil formation volume factor, permeability, viscosity, and pressure. We call these data post-discovery parameters because they are only available after discovery through exploration drilling. A data-driven approach to estimating post-discovery parameters of an unexplored oilfield is developed based on its pre-discovery data by learning from proven reservoir data. Using the Gaussian mixture model, and a data-driven reservoir typology based on the joint probability distribution of post-discovery parameters is established. We came up with 12 reservoir types. Subsequently, an artificial neural network classification model with the resilient backpropagation algorithm is used to find relationships between pre-discovery data and reservoir types. Based on k-fold cross-validation with k = 10, the accuracy of the classification model is stable with an average of 87.9%. With our approach, an investor considering acquiring an unexplored oilfield can classify the oilfield's reservoir into a particular type and estimate its post-discovery parameters' joint probability distribution. The investor can incorporate this information into a valuation model to calculate the production rates more accurately, estimate the oilfield's value and risk, and make an informed acquisition decision accordingly.

Oxide and Interface Defect Analysis of lateral 4H-SiC MOSFETs through CV Characterization and TCAD Simulations

We investigated oxide and interface defects of lateral 4H-SiC MOSFETs through capacitance-voltage (C-V) and conductance-voltage (G-V) characterization at various frequencies and temperatures. By employing consecutive up and down sweeps of the gate voltage at three different temperatures, we experimentally characterized the hysteresis width as the difference between up and down sweeps in the depletion to accumulation (d-a) and depletion to inversion (d-i) regions. We observed an increase in the hysteresis width with decreasing temperature. Although the hysteresis width is not affected by the small-signal frequency, at the same time, increasing the frequency leads to a strong stretch-out effect, especially in the d-i region.Our measurement results indicate that the hysteresis deformation of the C-V curves is dominated by three different trap types. First, interface acceptor-like defects located close to the conduction band can follow the small-signal frequency. Slower acceptor-like border traps with trap levels both close to the conduction band and in the middle of the band gap are however responsible for the increase of trapped negative charge with increasing gate voltage. Finally, we assume the presence of a fixed positive charge.

FIELD EVALUATION OF LURES AS CANDIDATE ATTRACTANTS FOR COASTAL CULICOIDES IN FLORIDA

Biting midges (Diptera: Ceratopogonidae: Culicoides) along the coast of Florida are a severe biting nuisance that can impede outdoor activities. Methods currently available for biting midge control are limited due to environmentally sensitive larval habitats and the lack of adulticide techniques available for area-wide population suppression.Homeowners that live along the coast can protect their homes with the use of fine- meshed window screens and fans, coarse low volume adulticide applications, and adult removal via commercial mosquito traps. There are known attractants that have been used to enhance trap captures for adult mosquitoes, and it is logical to test these attractants against closely related adult hematophagous Diptera such as Culicoides. This study compared four attractant lures, octenol, BG lure, R-octenol, and USDA red blend, known to be attractive to mosquitoes, and tested them against C. furens and C. mississippiensis as an addition to increase trap capture. Although all attractants increased trap capture above the control, results from this study could not identify a lure that was significantly more attractive to Culicoides species captured in Cedar Key, Florida. Further studies evaluating species specific trap types as well as attractants are needed to develop an effective Culicoides adult trapping control system as part of an integrated biting insect control program.

Trap Characterization of Trench-Gate SiC MOSFETs Based on Transient Drain Current

The SiC/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interface state is one of the main factors that limit the performance and reliability of the SiC metal-oxide-semiconductor field-effect transistor (MOSFET). In this paper, we use a Bayesian deconvolution algorithm to optimize trap feature extraction based on the transient current method and improve the trap extraction accuracy. Using this method, we study the trap capture mechanism in SiC MOSFETs and mainly characterize the trap position, the trap energy level, and the capture time constant. The results obtained show that there are three different types of traps and defects, two of which are SiC interface traps at the gate-source and gate-drain interfaces, with activation energies of 0.089 eV and 0.035 eV, respectively; the third trap type is an oxide trap, and its time constant does not vary with temperature. The characterization results are verified via deep level transient spectroscopy, and the results show reasonable agreement with those obtained by the method proposed in this paper. This method can be combined with electrical stress testing in long-term reliability research to realize nondestructive characterization of the defects of SiC MOSFETs.

Different Trap Types Depict Dissimilar Spatio-Temporal Distribution of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Cotton Fields

Pheromone-baited traps have been widely used for the monitoring of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), in order to time any control measures during the growing season. Different monitoring techniques may provide differential results regarding adult captures. However, studies on the comparative evaluation of the performance of different trap types on the captures of H. armigera are limited. To close this gap, in the present study, three different funnel traps (striped, green, and colored) were simultaneously evaluated in Central Greece, one of the main cotton-producing geographical zones in the European Union, in order to compare trap performance on the captures of H. armigera, as well as to depict the distribution of this species per trap in the study area. A differential performance of the different trap types tested, expressed as numbers of adults captured, was recorded. Specifically, the striped trap captured many more adult moths than the other two trap types. Given that the only difference among these traps was the color of the external trap surface, we hypothesize that trap color does matter in the case of H. armigera, and it is likely that brighter colors may be more attractive than darker ones.

Trap‐Dependent Optical/Thermal Stimulated Luminescence of Gallate Phosphors Charged by UV–visible–NIR light for Multiplexed Data Storage

AbstractUV‐charged optical stimulated single‐band phosphors are being used for single‐level optical data storage because of their ability to easily write/read information by light. In contrast, UV–visible–NIR rechargeable optical stimulated double‐band phosphor is urgently necessary for multiplexed high‐throughput optical data storage. Here, the authors design and synthesize Mn2+,Cr3+ co‐doped zinc gallate storage persistent phosphor that exhibits strong red‐green bicolor persistent luminescence (PersL). Besides the traditional ultraviolet charging, the phosphor can be effectively and repeatedly charged by using visible and NIR light by one‐ or two‐photon process. Interestingly, red and green PersL exhibit the opposite temperature dependence, which is extremely important for multilevel information storage. The mechanism of temperature‐dependent PersL intensity based on different trap types and filling approaches for the double luminescence centers is proposed. The phosphor promises a sophisticated application in optical data storage of wavelength multiplexing.

Invertebrate’s diversity on persimmon crop (Diospyros kaki Thunb.) at low altitude in Mechtras region, North Algeria

The inventory of invertebrates on persimmon cultivation using two methods of sampling, Barber traps and colored traps in Mechtras region (Tizi-Ouzou) Algeria, allowed us to collect 115 species divided into 58 families, belonging to 13 orders and 6 classes. The values of the centesimal frequencies applied to invertebrates orders identified in the studied plot vary from one type of trapping to another, each sampling method relates to a representative order group. The diets of insects are extremely diverse, due to the structures and function of the mouthparts, the structural and functional division of the digestive tract; we have established 8 trophic classes. Shannon-Weaver diversity index values are quite high in the study plot. The fairness obtained for each type tend towards 1, which reflects a balance between the species.

Can morphological traits explain species-specific differences in meta-analyses? A case study of forest beetles.

Meta-analyses have become a valuable tool with which to synthesize effects across studies, but in ecology and evolution, they are often characterized by high heterogeneity, where effect sizes vary between studies. Much of this heterogeneity can be attributed to species-specific differences in responses to predictor variables. Here, we aimed to incorporate a novel trait-based approach to explain species-specific differences in a meta-analysis by testing the ability of morphological traits to explain why the effectiveness of flight-intercept trap design varies according to beetle species, a critical issue in forest pest management. An existing morphological trait database for forest beetles was supplemented, providing trait data for 97 species, while data from a previous meta-analysis on capture rates of bark or woodboring beetles according to different trap designs were updated. We combined these sources by including nine morphological traits as moderators in meta-analysis models, for five different components of trap design. Traits were selected based on theoretical hypotheses relating to beetle movement, maneuverability, and sensory perception. We compared the performance of morphological traits as moderators versus guild, taxonomic family, and null meta-analysis models. Morphological traits for the effect of trap type (panel vs. multiple-funnel) on beetle capture rates improved model fit (AICc ), reduced within-study variance (σ2 ), and explained more variation (McFadden's pseudo-R2 ) compared with null, guild, and taxonomic family models. For example, morphological trait models explained 10% more of the variance (pseudo-R2 ) when compared with a null model. However, using traits was less informative to explain how detailed elements of trap design such as surface treatment and color influence capture rates. The reduction of within-study variance when accounting for morphological traits demonstrates their potential value for explaining species-specific differences. Morphological traits associated with flight efficiency, maneuverability, and eye size were particularly informative for explaining the effectiveness of trap type. This could lead to improved predictability of optimal trap design according to species. Therefore, morphological traits could be a valuable tool for understanding species-specific differences in community ecology, but other causes of heterogeneity across studies, such as forest type and structure, require further investigation.

Three trap designs evaluated for a deepwater lionfish fishery

A deepwater (&amp;gt;40 m) fishery for invasive lionfish (Pterois volitans/miles) offers a potential means to control invasive lionfish densities and mitigate their impacts on reefs too deep for SCUBA removals. Trapping could provide a scalable solution—if an effective fishing gear with minimal environmental impacts could be permitted and adopted by fishers. We tested the efficacy of wooden slat lobster traps, wire sea bass traps, and experimental non-containment Gittings traps. One hundred deployments of each trap type were made at 120 mesophotic (38–78 m deep) natural reef sites in the northeastern Gulf of Mexico (29.6–30.1°N, 86.1–87.6°W). Reef sites were surveyed with remotely operated vehicles (ROV) before and after trap deployments, and remote time-lapse video cameras were affixed above 86 traps to sample in situ recruitment to the traps. The video data showed that lionfish were attracted to the vicinity of the three trap types at similar rates, but that lionfish rarely entered the lobster or sea bass traps. The high bycatch rates of sea bass traps suggested their use is likely unsuitable for targeting lionfish. Lobster traps had lower rates of bycatch, but their relatively high ratio of bycatch-to-lionfish catches suggests that modifications will be needed to make them more efficient. The Gittings traps had the highest lionfish catch rates and lowest bycatches of native fishes, but operational issues were also identified. They failed to open on 20% of deployments and one entangled a green sea turtle (Chelonia mydas). Even with the best-performing trap design, the average catch rate of lionfish was less than one lionfish per trap. A potential explanation could be the low biomass of lionfish observed during the ROV surveys, which averaged 0.3 kg lionfish per site. The time-lapse video data suggested that lionfish recruitment to Gittings traps could increase with higher densities of lionfish on the nearby reefs, if traps were retrieved after approximately two days of deployment, and if traps were retrieved during dawn or dusk. Further research, development, and testing is needed for lionfish traps, and critical bio- and techno-economic assessments appear warranted to evaluate the feasibility of a deepwater lionfish fishery.

Predicting the Excitation Dynamics in Lanthanide Nanoparticles

AbstractWith their dipole‐forbidden 4f transitions, lanthanides doped in nanoparticles promise high excited state lifetimes and quantum yields that are required for applications such as composite lasers or nanoscale quantum memories. Quenching at the nanoparticle surface, however, severely reduces the lifetime and quantum yield and requires resource‐consuming experimental optimization that could not be replaced by simulations due to the limitations of existing approaches until now. Here, a versatile approach is presented that fully accounts for spatiotemporal dynamics and reliably predicts the lifetimes and quantum yields of lanthanide nanoparticles. LiYF4:Pr3+nanoparticles are synthesized as a model system, and the lifetimes of a concentration series (≈10 nm, 0.7−1.47 at%) are used to match the model parameters to the experimental conditions. Employing these parameters, the lifetimes and quantum yields of a size series (≈5 at%, 12−21 nm) are predicted with a maximum uncertainty of 12.6%. To demonstrate the potential of the model, a neutral shell is added around the core particles in the model which extends the lifetime by up to 44%. Furthermore, spatiotemporal analysis of single nanoparticles points toward a new type of energy trapping in lanthanide nanoparticles. Consequently, the numerical optimization brings applications such as efficient nanoparticle lasers or quantum memories within reach.

First Evidence of Electron Trapped Ln2+ Promoting Afterglow on Eu2+, Ln3+ Activated Persistent Phosphor‐Example of BaZrSi3O9:Eu2+, Sm3+

AbstractBaZrSi3O9:Eu2+, Sm3+ (Em:525 nm) is prepared. The role played by the trivalent co‐doping ion Sm3+ in the afterglow and the type of trap are clarified. BaZrSi3O9:Eu2+, Sm3+ is found to produce Sm2+ during the excitation by X‐ray absorption near‐edge structure (XANES), etc., and it is thus proved that Sm3+ exists as an electron trap in the afterglow process. In the field of persistent phosphors activated by Eu2+ and Re3+ such as Sm3+ or Dy3+ having been widely utilized as emergency guide lights, clock faces, etc. for &gt; 25 years, for the first time it is successfully observed that after excitation Re2+ is formed, transferring its electron to 5d band of Eu2+, returning to Re3+ by itself, where the decrease in Sm2+ coincides with the increase in Sm3+, and the two decay time τ1 and τ2 of PL (5D0→7F0) of Sm2+ coincides with the two evolution time of PL (5d→4f) of Eu2+. The behavior of electron transfer from Sm2+ to Eu2+ as a key of afterglow is detected. The detailed afterglow mechanism is proposed by analysis of thermoluminescence and defect reaction, which is very important for the in‐depth investigation of the long afterglow material and the further improvement of the mechanism.