Release Point Research Articles

Real-World Evidence on the Effectiveness of Plexiglass Barriers in Reducing Aerosol Exposure.

Barriers are commonly installed in workplace situations where physical distancing cannot be maintained to reduce the risk for transmission of respiratory viruses. Although some types of barriers have been shown to reduce exposure to aerosols in laboratory-based testing, limited information is available on the efficacy of barriers in real-world settings. In an acute care hospital, we tested the effectiveness of in-use plexiglass barriers in reducing exposure of staff to aerosolized particles. A nebulizer was used to release 5% NaCl aerosol 1 meter from staff members with and without the barrier positioned between the point of aerosol release and the hospital staff. Particle counts on the staff side of the barrier were measured using a 6-channel particle counter. A condensed moisture (fog) generating device was used to visualize the airflow patterns. Of 13 in-use barriers tested, 6 (46%) significantly reduced aerosol particle counts detected behind the barrier, 6 (46%) reduced particle counts to a modest, non-significant degree, and 1 (8%) significantly increased particle counts behind the barrier. Condensed moisture fog accumulated in the area where staff were seated behind the barrier that increased particle exposure, but not behind the other barriers. After repositioning the ineffective barrier, the condensed moisture fog no longer accumulated behind the barrier and aerosol exposure was reduced. In real-world settings, plexiglass barriers vary widely in effectiveness in reducing staff exposure to aerosols, and some barriers may increase risk for exposure if not positioned correctly. Devices that visualize airflow patterns may be useful as simple tools to assess barriers.

Sulfonate-functionalized ionic liquids for pH-sensitive alginate beads preparation: Macromolecular structure study and drug release evaluation

Aiming at a new application of ionic liquids in the formation of biomaterials, polymeric hydrogel beads sensitive to pH were produced based on alginate, using sulfonate ionic liquids (ILs) in a novel way as crosslinking agents. Among the tested ILs, the new functionalized IL A1 [1-(4-ethoxy-1-butylsulfonic)-3-methylimidazolium bromide] was synthesized for the first time. The IL A1 and the IL A2 (triethylammonium hydrogen sulfate) resulted in the formation of beads by drip method. Their structural representation was obtained from the molecular docking, allowing a study of their molecular interactions. Tests of variation in the degree of swelling showed that under pH 6.0 and 7.4, the beads dissolved in a few minutes; while under pH 1.2, they remain stable for at least 7 h. The lower degree of swelling in relation to time obtained for the systems resulted in beads with more compact structures, when compared to swelled beads formed with alginate and conventional bivalents ions. Cumulative release point of 5-fluorouracil and indomethacin remained sustained until at least 8 h, under pH 1.2. The lower energy conformations were calculated for each macromolecule combination of bead-drug, and was obtained that the 5-fluorouracil interacts more strongly with the beads structural network than indomethacin, resulting in a slower release that reached 9.84% (w/w) against 25.00% (w/w). These results indicate a potential application for the ionic liquids-beads as a site-specific drug carrier.

Can parasitism by Tamarixia radiata (Hymenoptera: Eulophidae) affect the movement and oviposition behavior of Diaphorina citri (Hemiptera: Psyllidae)?

Diaphorina citri is the vector of the bacterium that cause “huanglongbing” (HLB). The psyllid acquires the pathogen after feeding on infected plants and transmits it to other trees as it moves through the orchard. The psyllid’s movement is directly affected by abiotic and biotic factors, such as the presence of conspecific insects and natural enemies. We evaluated the effects of the presence of conspecific nymphs either not parasitized or parasitized by Tamarixia radiata on the movement and oviposition of adult female D. citri. Diaphorina citri females were released into cages containing a row of four equidistant Murraya paniculata plants. The first plant, the release point, had one of three conditions: no nymphs; non-parasitized nymphs (high and low densities); or previously parasitized nymphs. At 24, 48, and 72 h following release, the females on each plant in the cage were counted. At the end of the observations (72 h), the females were removed, and the eggs laid on the plants were counted. The presence of non-parasitized nymphs, at low and high densities, increased the tendency of adult movement and reduced the total number of laid eggs, compared with cases in which nymphs were absent. On the other hand, the presence of nymphs increased the egg distribution by females over all available plants in the cages. In these cases, higher number of adult females and eggs were observed in plants without nymphs, compared with the plant in which nymphs were present (release point). The conditions of nymphs, i.e., if parasitized or not, did not change the movement behavior and the distribution of eggs deposited over plants in the cages. However, the number of eggs laid by females was low for the cases in which the nymphs were parasitized. The findings can contribute to establishing the optimal of application of the psyllid management techniques, and improving the efficiency of natural enemy releases considering that the pest can be present at the field in different life stages.

A sterile insect technique pilot trial on Captiva Island: defining mosquito population parameters for sterile male releases using mark–release–recapture

BackgroundThe sterile insect technique (SIT), which involves area-wide inundative releases of sterile insects to suppress the reproduction of a target species, has proven to be an effective pest control method. The technique demands the continuous release of sterilized insects in quantities that ensure a high sterile male:wild male ratio for the suppression of the wild population over succeeding generations.MethodsFor these releases, it is important to determine several ecological and biological population parameters, including the longevity of the released males in the field, the dispersal of the released males and the wild pest population size. The Lee County Mosquito Control District initiated a study in a 47-ha portion of Captiva Island (Florida, USA), an island with a total area of 230 ha, to define biological SIT parameters for Aedes aegypti (L.), an invasive disease-vectoring mosquito known to be difficult to control due to a combination of daytime biting activity, use of cryptic breeding habitats that are difficult to target with conventional night-time ultra-low volume methods, and emerging resistance to commonly used insecticides. Another goal was to assess patterns of dispersal and survival for laboratory-reared sterile Ae. aegypti males released over time in the pilot site. These parameters will be used to evaluate the efficacy of a SIT suppression program for Ae. aegypti on Captiva Island.ResultsOver the course of seven mark-release-recapture studies using single- and multiple-point releases, 190,504 sterile marked males were released, for which the recapture rate was 1.5% over a mean period of 12 days. The mean distance traveled by sterile males of the local strain of Ae. aegypti that has colonized Captiva Island was 201.7 m from the release point, with an observed maximum traveled distance of 404.5 m. The released sterile mosquitoes had a probability of daily survival of 0.67 and an average life expectancy of ~ 2.46 days.ConclusionsThese data together with the population size estimate and sterile:wild ratio provide a solid basis for planning the SIT operational phase which is aimed at mosquito population suppression.Graphical abstract

Biodegradability enhancement of phenolic wastewater using hydrothermal pretreatment

A novel hydrothermal pretreatment was applied for the biochemical treatment of phenolic wastewater with high concentrations of phenolic substances. The results demonstrated that 250 °C was the reaction temperature dividing point for complete oxidation, hydrothermal gasification, and amino release from carbonaceous organics in phenolic wastewater. Before the dividing point reached, some of the large molecules were hydrolyzed into small molecules of volatile phenolic substances that were easily adsorbed by the activated sludge. After the integrated hydrothermal pretreatment and anaerobic/aeration process, the removal rate of volatile phenolswas respectively reached by 97 % and 88 % with hydrothermal temperature of 250 °C and without pretreatment. Functional microorganisms (i.e., Chloroflexi) responsible for aromatic compounds degradation were enriched, thus the dioxygenases, dehydrogenase reactions, and meta-cleavage of catechol were enhanced. This work provided an innovative approach to remove phenolic substances from phenolic wastewater, and in-depth understandings of microbial responses in biochemical systems.

The Release of Trichogrammatoidea armigera parasitoid for the Parasitization of Helicoverpa armigera Eggs in Maize

Background: Helicoverpa armigera (Hübner) is a common polyphagous pest on corn cob. H. armigera that is controllable through Trichogrammatoidea armigera (Nagaraja) parasitoid release. Successful inundated release of parasitoids depends on parasitization and parasitoid dispersal. Methods: The experiment consisted of 2 parasitoid release plots and 1 no release plot. T. armigera parasitoid was released twice, at 45 DAP and 52 DAP (Day after planting) in the middle of the experimental plot. The dose of parasitoid released during the corn generative phase was 1000 individuals per 254 m2 (~ 40000/ha). Evaluation was carried out by collecting the eggs of H. armigera 3 days after release at radius 1, 3, 6 and 9 m in all cardinal directions from the release point. Result: The release of parasitoids increased the eggs parasitization of H. armigera in 45 DAP tot he tune of 51.91% and 52 DAP was 38.57%. The wind direction did not affect the parasitoid movement which is active and almost uniform in all cardinal directions. Parasitoid movement was slightly similar in all distances and cardinal directions. The distribution of parasitoids reached 9 m from 40 release points ha-1 in colonies. T. armigera parasitoids were grouped hence, the monitoring in corn was carried out systematically.

Adaptive mutant particle swarm optimization based precise cargo airdrop of unmanned aerial vehicles

Emerging unmanned system technologies and smart logistics have motivated logistics enterprises to use unmanned aerial vehicles (UAVs) for last-mile cargo delivery through the air so as to benefit from its flexibility and low cost. It is useful to deliver cargoes by airdrops from fixed-wing UAVs. However, wind and parameter errors of the UAV could make the cargo deviate from the desired landing point. To improve the accuracy of airdrop methods, this paper presents the Continuously Computed Release Point under conditions of strong wind (SW-CCRP) airdrop strategy to transport the cargo to a given position by a fixed-wing UAV. In this strategy, a set of differential equations are used to model the cargo motion and wind perturbations are considered. Based on the established motion model and the kinematic relationships between the cargo and the target position, the expected release point can be accurately predicted in real time. In order to satisfy the precision requirement, the precision assignment is studied to determine the permissible parameter error ranges. In view of that the conventional precision assignment methods are difficult to be applied in the airdrop system because of its complexity and strong nonlinearity, an adaptive mutant particle swarm optimization (AMPSO) algorithm is proposed to solve this problem, in which the adaptive inertia weight can balance the global and local search. In addition, the mutation factor of the AMPSO is able to avoid premature convergence and stagnation. Finally, two specific test scenarios are designed to validate the effectiveness of the proposed approaches.

Mangrove Propagule Dispersal in a Shallow and Narrow Coastal Lagoon: A Simulation-Based Assessment of the Setiu Wetlands, Malaysia

The short- to long-distance dispersal (SDD and LDD) of propagules is critical for the regeneration of mangrove forests. Mark–recapture experiments are considered to be a good tool for assessing such dispersal patterns. However, dense mangrove roots, exposed mudflats, shallow water, etc. often limit the number of recaptured propagules and their implication studies. Therefore, a combination of hydrodynamic and particle tracking models, together with a mark–recapture experiment, were applied to identify the dispersal behavior of Rhizophora mucronata Lamk. propagules in a coastal lagoon of Setiu Wetlands, Malaysia. The transport trajectories revealed that the dispersal of propagules is leptokurtic, with majority of them confined to very-short-distance dispersal (VSDD; 3–5 m) to SDD (1400 m). While higher obstacle density (e.g., mangrove roots) constrained the propagule dispersal, weaker tidal currents that coupled with less upstream discharge increased their retention time and settlement closer to the point of release. Under this scenario, the chances for propagules to exit from the lagoon mouth and their entry into the open waters for LDD are very limited. These results can explain the abundance of Rhizophora spp. in the northern sector of the Setiu Wetlands and be useful for species-level conservation/management.

Simultaneous external and internal marking of Triatoma sordida nymphs: trace element efficacy and microgeographic dispersal in a peridomestic Brazilian Cerrado rural household

BackgroundChagas disease (American trypanosomiasis) is an important neglected tropical illness, which has the flagellate protozoan Trypanosoma cruzi as etiological agent and blood-feeding insects of the Triatominae subfamily as vectors. Despite its importance for disease epidemiology, field studies targeting microgeographic dispersal of triatomines in endemic areas are rare. The ability wingless nymphs have to move (crawl) within peridomestic settings is a key component regarding the design and development of rational control strategies.MethodsWe double-marked Triatoma sordida fourth-instar nymphs (N4) with a reliable fluorescent dye and a trace element. This new methodology allowed us to simultaneously evaluate (i) nymph dispersal and (ii) the effectiveness of copper (Cu), chromium (Cr), and cadmium (Cd) trace elements as potential new markers. In the mark-release-recapture (MRR) experiment, 390 T. sordida N4 were released in the peridomicile of a single rural household, 130 individuals at each of three release points, at distances of 2, 5, and 10 m from the chicken coop (CC) and 27, 32, and 35 m away from the horse corral (HC). All specimens were double marked (Cu/blue, Cr/orange, Cd/green). Recaptures occurred in two intervals: 1–3 days and 15–17 days after release.ResultsSpecimens were successfully recaptured at all distances up to 10 m. A total of 19, 23, and 10 specimens were able to disperse 2, 5, and 10 m, respectively, to reach the CC. No insects were recaptured at the HC. Of the three analyte/paint combinations tested, Cr/orange gave the most promising results; Cu/blue marker and Cd/green marker performed very poorly with only 4/19 and 0/10 analyte/paint ratios, respectively.ConclusionsTriatoma sordida N4 could cover a distance of 10 m in 17 days. This indicates that nymphs seem to have a reduced dispersal capability compared to adults. Ninety-one percent of the 22 recaptured orange-marked nymphs were still Cr positive after the 17-day period evaluated. This makes this analyte a good candidate for future investigations that will apply this marking method in MRR studies.Graphical

A systematic methodological approach to estimate the impacts of a classical biological control agent’s dispersal at landscape: Application to fruit fly Bactrocera dorsalis and its endoparasitoid Fopius arisanus

Following the invasion of Africa by the oriental fruit fly, Bactrocera dorsalis, Classical biological control (CBC) has been exploited as a safer alternative for its suppression by the introduction and release of the koinobiont endoparasitoid, Fopius arisanus. Although the parasitoids have been released in several African countries, the extent of their dispersal and the resulting extent in benefits to fruit growers have not yet been elucidated. This paper proposes an innovative, multi-level CBC impact analysis that combines cellular automata (CA) and ecological niche models to estimate parasitoid dispersal ranges and the range of farmers who benefit from it. Firstly, we provided a generic, systematic methodological approach using CA rules incorporated into species distribution. Secondly, the model was used to estimate the dispersal range of the parasitoid, based on the life history and bioecology of the host insect (fruit fly) and the parasitoid. Finally, the parasitoid dispersal coverage was mapped across fruit crops attacked by the target fruit fly, and the number of households that benefited from the parasitoids release programme was extracted from the area of the dispersal. The data was projected across all countries where the parasitoid has been released and validated. In Kenya, the model showed that F. arisanus had covered a total area of 50.34 km2 from the initial point of open field release; and at the continental scale, the model predicted that the parasitoid had covered a total area of 229.97 km2. The model estimated that 351,855 and 3,731,330 households had directly benefited from the release of F. arisanus between 2013 and 2018 in Kenya and at the continental level, respectively. The study's outcome is appropriate for providing feedback information on the impact of CBC to government and development partners to assist in making informed decisions on technological interventions.

Urea-Bond Scission Induced by Therapeutic Ultrasound for Biofunctional Molecule Release.

Ultrasound-triggered remote control of biomolecular functions in cells provides unique advantages for us to interrogate nature. However, strategies to design therapeutic ultrasound-responsive functional molecules remain elusive, and rare ultrasound-cleavable chemical bonds have been developed to date. Herein, therapeutic ultrasound (1 MHz)-induced scission of urea bonds for drug release is demonstrated for the first time. Such a transformation has been verified to be initiated by hydroxyl radicals generated in the interior of cavitation bubbles, occurring specifically at the cavitation bubble-liquid interface. A series of urea-bond-containing prodrugs based on methylene blue (MB), namely MBUs, are designed. Upon sonication with low-intensity therapeutic ultrasound, the urea bonds linked with primary amines can be selectively cleaved, and free MB is released in a physiologically relevant environment, accompanied by recovered absorbance, fluorescence, and photosensitivity. Moreover, an FDA-approved alkylating agent (i.e., melphalan) bearing urea bond is also developed (MBU-Mel), successfully achieving ultrasound-triggered drug release in deep-seated cancer cells (mimic with 1 cm pigskin), showing the scalability of our ultrasound-responsive molecule platform in bioactive molecules release. This may set the starting point for therapeutic ultrasound-induced drug release, making a forward step in "sonopharmacology".

A Proposed DISE Approach for Tourist Destination Crisis Management

Novel coronavirus (COVID-19) has had a huge impact on the global tourism industry over the past couple of years. Most previous studies investigated tourism crises after the pandemic period. Hence, to minimize the research gap, the present study investigates the impact of COVID-19 on tourism during the pandemic period. By assessing this impact, this paper proposes a D (big data) I (impact module) S (strategy module) E (evaluation module) model to cope with the crisis in order to bring about feasible implications for tourism practitioners and governments. This paper is to provide real-time destination management adjustments. This model is based on a crisis management framework and governance theory through retrieving big data from China Unicom and major travel information delivery sources. The major finding shows that the detailed time points of pandemic information release in the early stage of crisis. In conclusion, through proposing a DISE model, the present study assesses the impact of the major emergency public health crisis, assists destination managers in adjusting tourism-related policy and reflects the priority of recovering tourism after the crisis for effective tourist destination management.

Oviposition preferences of the oriental fruit moth Grapholita molesta (Lepidoptera: Tortricidae) to pear HIPVs

Herbivore-induced plant volatiles (HIPVs) are regarded as an indirect plant defense against herbivores, since they attract natural enemies to infested plants. On the other hand, HIPVs also affect behavioral responses of herbivores. In a previous study, Lytopylus rufipes, a parasitoid of the oriental fruit moth (Grapholita molesta), showed positive responses to pear HIPVs, but the influence of pear HIPVs on G. molesta is still unclear. To better understand these responses, we first tested oviposition preferences of G. molesta to uninfested and infested pear shoots (US and IS, respectively) and uninfested mature leaves (ML) in dual-choice bioassays using a cylindrical tube. Then, preferences to volatile components were also assessed. G. molesta females preferred US-, IS-, and ML-treated areas compared to the control area (no leaves), respectively. Subsequently, G. molesta females preferred IS over US, and US more than ML in bioassays. Furthermore, G. molesta females did not show any significant preference for individual volatile components, but more eggs were laid in an area treated with a synthetic pear HIPV blend, compared to the hexane-treated area (control). These results indicate that G. molesta females do not avoid infested pear shoots nor HIPVs. Moreover, HIPVs may recruit not only natural enemies, but also G. molesta females to the release point of HIPVs. Thus, it is important to examine responses of G. molesta females to HIPVs in the field before employing them for pest management.

Contaminant release, mixing and microbial fluctuations initiated by infiltrating water within a replica field-scale legacy radioactive waste trench

Numerous legacy near-surface radioactive waste sites dating from the mid 20th century have yet to be remediated and present a global contamination concern. Typically, there is insufficient understanding of contaminant release and redistribution, with invasive investigations often impractical due to the risk of disturbing the often significantly radiotoxic contaminants. Consequently, a replica waste trench (~5.4 m3), constructed adjacent to a legacy radioactive waste site (Little Forest Legacy Site, LFLS), was used to assist our understanding of the release and mixing processes of neodymium (Nd) — a chemical analogue for plutonium(III) and americium(III), two significant radionuclides in many contaminated environments. In order to clarify the behaviour of contaminants released from buried objects such as waste containers, a steel drum, representative of the hundreds of buried drums within the LFLS, was placed within the trench. Dissolved neodymium nitrate was introduced as a point-source contaminant to the base of the trench, outside the steel drum. Hydrologic conditions were manipulated to simulate natural rainfall intensities with dissolved lithium bromide added as a tracer. Neodymium was primarily retained both at its point of release at the bottom of the trench (>97 %) as well as at a steel container corrosion point, simulated through the emplacement of steel wool. However, over the 8-month field experiment, advective mixing initiated by surface water intrusions rapidly redistributed a small proportion of Nd to shallower waters (~1.5–1.7 %), as well as throughout the buried steel drum. Suspended particulate forms of Nd (>0.2 μm) were measured at all depths in the suboxic trench and were persistent across the entire study. Analyses of the microbial communities showed that their relative abundances and metabolic functions were strongly influenced by the prevailing geochemical conditions as a result of fluctuating water depths associated with rainfall events. The site representing steel corrosion exhibited divergent biogeochemical results with anomalous changes (sharp decrease) observed in both dissolved contaminant concentration as well as microbial diversity and functionality. This research demonstrates that experimental trenches provide a safe and unique method for simulating the behaviour of subsurface radioactive contaminants with results demonstrating the initial retention, partial shallow water redistribution, and stability of particulate form(s) of this radioactive analogue. These results have relevance for appropriate management and remediation strategies for the adjacent legacy site as well as for similar sites across the globe.

Movement Patterns of Juvenile Loggerhead Turtles (Caretta caretta L. 1758) and Green Turtles (Chelonia mydas L. 1758) Hatched in Captivity and Released in the Korean Waters.

Simple SummaryDespite the continuous observation and drift of globally endangered sea turtles in Korean waters, relevant research and protection policies are deficient. To restore sea turtle populations near Korea, the Ministry of Oceans and Fisheries, Republic of Korea, has been hatching and rearing sea turtles in captivity and releasing juveniles into the sea. We satellite-tracked juvenile loggerhead and green turtles to confirm their movement patterns and adaptability in the wild. The tracked sea turtles used sea currents for movement, and the tracking duration and movement patterns differed according to their body size. In addition, while the loggerhead turtles moved to the Northeast East Sea, the green turtles tended to move west or southwest from the release point. By considering the release time and location, according to the growth level and species, the adaptability of artificially hatched and reared turtles to natural habitats is expected to be high.With most sea turtle populations declining, activities to conserve their habitat and nesting grounds and restore their populations are being implemented worldwide. To preserve the Northwestern Pacific populations, the National Marine Biodiversity Institute of Korea has been releasing artificially propagated sea turtles, but whether these individuals join the wild population remains unknown. The present study aimed to determine the movement patterns of artificially propagated juvenile loggerhead (Caretta caretta) and green (Chelonia mydas) turtles fitted with satellite transmitters on their carapaces and released in the waters of Jeju or Yeosu, Republic of Korea, between August 2018 and April 2022. Loggerheads traveled northward to the East Sea, whereas green turtles moved west or southwest. Two 36-month-old and two 48-month-old loggerheads moved toward their potential nursery grounds and toward their feeding grounds, respectively. Three green turtles with a curved carapace length (CCL) of <40 cm moved toward their nursery or feeding grounds, while three individuals (CCL > 45 cm) moved toward their inshore foraging areas. The travel paths were closely related to the direction of local sea currents. Our results implied that releasing artificially propagated sea turtles, considering their age and CCL, can positively contribute to the conservation of Northwestern Pacific populations.

Standoff Infrared Measurements of Chemical Plume Dynamics in Complex Terrain Using a Combination of Active Swept-ECQCL Laser Spectroscopy with Passive Hyperspectral Imaging

Chemical plume detection and modeling in complex terrain present numerous challenges. We present experimental results from outdoor releases of two chemical tracers (sulfur hexafluoride and Freon-152a) from different locations in mountainous terrain. Chemical plumes were detected using two standoff instruments collocated at a distance of 1.5 km from the plume releases. A passive long-wave infrared hyperspectral imaging system was used to show time- and space-resolved plume transport in regions near the source. An active infrared swept-wavelength external cavity quantum cascade laser system was used in a standoff configuration to measure quantitative chemical column densities with high time resolution and high sensitivity along a single measurement path. Both instruments provided chemical-specific detection of the plumes and provided complementary information over different temporal and spatial scales. The results show highly variable plume propagation dynamics near the release points, strongly dependent on the local topography and winds. Effects of plume stagnation, plume splitting, and plume mixing were all observed and are explained based on local topographic and wind conditions. Measured plume column densities at distances ~100 m from the release point show temporal fluctuations over ~1 s time scales and spatial variations over ~1 m length scales. The results highlight the need for high-speed and spatially resolved measurement techniques to provide validation data at the relevant spatial and temporal scales required for high-fidelity terrain-aware microscale plume propagation models.

Bases for the development of management strategies for fruit flies (Diptera: tephritidae)

Ceratitis capitata and Anastrepha fraterculus (Diptera: Tephritidae) are polyphagous pests that cause yield and quality losses in fruit trees and increase production costs because they are quarantine pest in some export destination countries. The sterile insect technique (SIT), highly selective, has been implemented in several countries to control C. capitata, while for A. fraterculus the technique development is being investigated. The following were carried out: 1-analysis of fluctuation and spatial distribution of both wild pest species, and the correlation between the captures in traps and the levels of fruit damage, 2-analysis of sexual compatibility between local A. fraterculus and a population from Argentina and 3-dispersion analysis of sterile males of C. capitata in two regions. Seventy-nine Jackson traps with trimedlure and 88 McPhail traps with torula were monitored, and 5,700 fruits were sampled, in three fruit farms, during two seasons. In field cages, the sexual isolation index (ISI), and the kind of pairs formed according to the origin of sexes were determined. Besides, 20,000 sterile males of C. capitata TslV8 were released in two areas, and a network of 54 Jackson traps with trimedlure was installed, forming five rings concentric to the release points. Dispersion and longevity were estimated. Spearman's correlation coefficient between captures and percentage of infested fruits was 0.62 (P = 0.0001) for C. capitata with captures in McPhail traps, 0.34 (P = 0.02) with captures in Jackson trap, and for A. fraterculus 0.59 (P = 0.0001) with captures in McPhail traps. The ISI was significantly different from zero due to higher performance of Argentine adults. There were no differences between the frequency of the Uruguayan homotypic couples and the heterotypic couples, while the frequency of the Argentine homotypic couples was higher than the rest. Sterile males of C. capitata dispersed a standard distance of 127 m and 131 m to Salto and San José, respectively.

Release strategies of Telenomus podisi for control of Euschistus heros: a computational modeling approach.

The egg-parasitoid wasp Telenomus podisi has received attention as a biological-control agent for one of the most important soybean pests in Brazil, the stink bug Euschistus heros. As yet, no studies have conclusively established strategies for the release of T. podisi. We developed a computational model using cellular automata in the C programming language to investigate release strategies for T. podisi in soybean crops, in order to optimize the use of these wasps in managing E. heros, assuming a two-dimensional grid of cells corresponding to a soybean field. The release strategies capable of maintaining an E. heros population below the Economic Threshold level involved releasing a total of at least 15 000 female parasitoids per hectare, in three or four releases of 5000 or more (equivalent to approximately 7142 or more male and female parasitoids per hectare, assuming a sex ratio of 0.70). A 25-m spacing between release points or strips was indicated. The model is very sensitive to the variation in the number of parasitoids per release and in the number of releases, but little sensitive to the release mode and spacing values. The theoretical results produced by the computational model are expected to guide future field studies to improve T. podisi release plans for managing E. heros in soybeans. Therefore, we recommend the release strategy of three to four releases of 5000 or more female parasitoids per hectare, at points or strips spaced 25 m apart, to be tested in field experiments for proper implementation by producers. © 2022 Society of Chemical Industry.

The Spatial and Temporal Variations in the Superparasitism ofDiachasmimorpha longicaudataPopulation Lines on Different Hosts After Field Release.

Evaluating the behavior of the parasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) in the field allows improving strategies for its release. Thus, the aim of this study was to evaluate spatial and temporal variations in the superparasitism of two populations of D. longicaudata on two fruit fly hosts after releasing them in a guava (Psidium guajava L.; cultivar 'Paluma') orchard. The two parasitoid populations used were CS and AS, which were reared on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann), respectively. Four releases were carried out without host choice. Host larvae were offered to the parasitoids in sentinel traps attached at varying heights on the plant, and in plants located at eight different directions and seven distances (7.0, 21.0, 35.0, 49.0, 59.4, 63.0, and 69.3m) from the center of the parasitoid release point. The traps remained in the orchard for 24, 48, and 168h after release. After removing the traps, they were taken to the laboratory for scar counting. The percentages of parasitism, superparasitism, mortality, and emergence of parasitoids were determined. Data were analyzed using the generalized linear mixed-effect model (GLMM). The AS females were more active, as they exerted higher parasitism and superparasitism at the first distance and 48h after release, leaving a higher number of oviposition scars on the host A. fraterculus. Additionally, higher host mortality was observed in A. fraterculus at the closest points and the first 48h. The highest percentage of parasitoid emergence was observed in C. capitata parasitized by AS females.

Biliary Polycyclic Aromatic Hydrocarbon Metabolite Equivalents Measured in Fish and Subtidal Invertebrates Following the Refugio Beach Oil Spill.

Monterey formation crude oil spilled from an onshore pipeline and entered the surf zone near Refugio State Beach, Santa Barbara County, CA, USA on 19 May 2015. Exposure to nearshore fish was evaluated by measuring biliary polycyclic aromatic hydrocarbon (PAH) metabolite concentrations in surfperch (Embiotocidae), collected near the release point, at a lesser oiled area, Gaviota State Beach, and near the Coal Oil Point oil seep, Campus Point, at both four days and approximately one year after the oil spill. Three to four weeks after the spill, fish, invertebrates, and kelp were collected near the same three sites for PAH analysis of edible tissues to support the fishery closure assessment. Additionally, thirteen days after the spill, vegetation, and invertebrate tissue samples from the seafloor near Refugio State Beach were analyzed for PAHs. In surfperch bile, mean naphthalene, phenanthrene and benzo(a)pyrene metabolite equivalents were significantly higher at Refugio State Beach, compared to Gaviota State Beach or Campus Point in 2015. One year later, there was no significant difference between the three sites. Spatial and depth zone patterns of PAH tissue concentrations from composited invertebrate, vegetation and fish showed highest concentrations were measured in invertebrates collected near Refugio State Beach. Overall, results show elevated PAH levels in nearshore organisms and provide a useful reference for potential PAH exposures in fish and subtidal invertebrates following a large nearshore oil spill.