Ant nests increase litter decomposition to mitigate the negative effect of warming in an alpine grassland ecosystem.

Warming can decrease feeding activity of soil organisms and affect biogeochemical cycles. The ant Formica manchu is active on the nest surface and prefers a hot, dry environment; therefore, warming may provide a favourable environment for its activities. We hypothesized that F. manchu benefit from warming and mitigate the negative effects of warming on litter decomposition. We examined the effects of ant nests (nest absence versus nest presence) and warming (+1.3 and +2.3°C) on litter decomposition, soil properties and the plant community in alpine grassland. Decomposition stations with two mesh sizes were used to differentiate effects of microorganisms (0.05 mm) and macroinvertebrates (1 cm) on decomposition. Ant nests increased litter decomposition with and without macroinvertebrates accessing the decomposition station when compared to plots without ant nests. Only litter decomposition in ant nests with macroinvertebrates having access to the decomposition station was not affected negatively by warming. Plots with ant nests had greater soil carbon, nutrient contents and plant growth than plots without ant nests, regardless of warming. Our results suggest that ant nests maintain ecosystem processes and functions under warming. Consequently, a management strategy in alpine grasslands should include the protection of these ants and ant nests.

Twilight activity patterns and angling vulnerability of yellowmouth barracuda (Sphyraena viridensis Cuvier, 1829), a range-expanding thermophilic fish.

Among the thermophilic fishes that have become established in the north-western Mediterranean as a consequence of sea warming, the yellowmouth barracuda (Sphyraena viridensis Cuvier, 1829) appears to be one of the most successful and abundant in the coastal rocky environment, having increasingly become the object of recreational and commercial exploitation in the study area. Lure-fishing sessions were carried out from May 2016 to November 2018 in the Catalan Sea (NE Spain) at dawn and dusk, with the aim of providing new insight into the behavioural, spatial and feeding ecology and vulnerability to angling of this poorly known species. Generalized mixed-effects linear models showed that S. viridensis is a crepuscular inshore dweller, whose vulnerability to angling is significantly influenced by solar and lunar light intensities, being highest in the pre-spawn and spawning periods. Asymmetries between dawn and dusk activity patterns were detected, evidently related to a drop in aggressiveness at dusk following the spawning period. The simple study design adopted may be applied to other contexts, aiming to the recognition of several levels of fish vulnerability to angling.

Short-term effects of two fungicides on enchytraeid and earthworm communities under field conditions.

Because of the wide use of pesticides in agriculture, there is still a need of higher-tier field studies to assess ecotoxicological effects of commercial formulations on a wider variety of non-target soil organisms such as soil annelids. We here tested the effects of different concentrations of two fungicide formulations, i.e., Cuprafor Micro® (composed of 500 g kg-1 copper oxychloride) and Swing Gold® (composed of 50 g l-1 epoxiconazole and 133 g l-1 dimoxystrobin) on two families of terrestrial oligochaetes (Lumbricidae and Enchytraeidae) after 1 month of exposure. We also assessed the feeding activity of soil organisms using the bait lamina method. Along with the feeding activity, the enchytraeid density, diversity and communities were not different in the control and the contaminated plots. By contrast, epigeic earthworms were absent and earthworm diversity and densities of anecic species decreased significantly in the plots contaminated at ten times the recommended dose of the Swing Gold® formulation. The copper fungicide (at 0.75 and 7.5 kg Cu ha-1) and the treatment with the pesticide mixture (Cuprafor Micro® at 0.75 kg Cu ha-1 and Swing Gold® at the recommended dose) did not affect Oligochaeta communities compared with the control, except the Shannon index for earthworms in the mixture of both fungicides. Responses of the two annelid families to the tested pesticides were different with higher effects observed on the diversity and the community structure of earthworms compared with enchytraeids. This study allowed detecting early changes on oligochaete populations after pesticide application.

Effects of the herbicide Roundup® on the metabolic activity of Gammarus fossarum Koch, 1836 (Crustacea; Amphipoda).

Pesticides can easily reach surface waters via runoff and their potential to have detrimental impacts on freshwater organisms is high. Not much is known about how macroinvertebrates react to glyphosate contamination. In this study we investigated lethal and sublethal effects of the exposure of Gammarus fossarum to Roundup®, a glyphosate-based herbicide. The LC10 and LC50 values after 96 h were determined to be 0.65 ml/L Roundup® (230 mg/L glyphosate) and 0.96 ml/L Roundup® (340 mg/L glyphosate), respectively. As a sublethal measure of toxicity we conducted eight experiments with the feeding activity and the respiratory electron transport system (ETS) activity as endpoints. All experiments lasted seven days. Although the LC10 concentration of Roundup® was used for the feeding activity tests, 49% of the gammarids died before the end of the experiments, which is inconsistent with the calculated LC10-values. The feeding activity was significantly higher in Roundup®-enriched water (mean = 0.18 mg/mg x d) in comparison to pure spring water (mean = 0.079 mg/mg x d). No significant difference was observed between the ETS activity, which was determined after 24, 48 or 96 h after the start of the experiment, of the gammarids in Roundup® solution and in the control. The LC-values determined here are rather high, and exceed background glyphosate concentrations in most anthropogenically influenced surface waters. The increased feeding activity when exposed to Roundup® in combination with an unchanged ETS activity suggests effects on the metabolic efficiency of G. fossarum. We argue that Roundup® enhances the anabolic activity (feeding activity) in order to maintain the catabolic activity (ETS activity).

Serotonergic regulation of the buccal (feeding) rhythm of the pond snail, Lymnaea stagnalis. An immunocytochemical, biochemical and pharmacological approach.

Hatching is an important phase of the development of pulmonate gastropods followed by the adult-like extracapsular foraging life. Right before hatching the juveniles start to display a rhythmic radula movement, executed by the buccal complex, consisting of the buccal musculature (mass) and a pair of the buccal ganglia. In order to have a detailed insight into this process, we investigated the serotonergic regulation of the buccal (feeding) rhythm in 100% stage embryos of the pond snail, Lymnaea stagnalis, applying quantitative immunohistochemistry combined with the pharmacological manipulation of the serotonin (5-HT) synthesis, by either stimulating (by the 5-HT precursor 5-hydroxytryptophan, 5-HTP) or inhibiting (by the 5-HT synthesis blocker para-chlorophenylalanine, pCPA) it. Corresponding to the direction of the drug effect, significant changes of the fluorescence intensity could be detected both in the cerebral ganglia and the buccal complex. HPLC-MS assay demonstrated that 5-HTP increased meanwhile pCPA decreased the 5-HT content both of the central ganglia and the buccal complex. As to the feeding activity, 5-HTP induced only a slight (20%) increase, whereas the pCPA resulted in a 20% decrease of the radula protrusion frequency. Inhibition of 5-HT re-uptake by clomipramine reduced the frequency by 75%. The results prove the role of both central and peripheral 5-HTergic processes in the regulation of feeding activity. Application of specific receptor agonists and antagonists revealed that activation of a 5-HT1-like receptor depressed the feeding activity, meanwhile activation of a 5-HT6,7-like receptor enhanced it. Saturation binding plot of [3H]-5-HT to receptor and binding experiments performed on membrane pellets prepared from the buccal mass indicated the presence of a 5-HT6-like receptor positively coupled to cAMP. The results suggest that 5-HT influences the buccal (feeding) rhythmic activity in two ways: an inhibitory action is probably exerted via 5-HT1-like receptors, while an excitatory action is realized through 5-HT6,7-like receptors.

Predatory beetles feed more pest beetles at rising temperature.

BACKGROUND: Climate warming is a challenge for many plants and animals as they have to respond to rising temperature. Rising temperature was observed to affect herbivores and predators. Activity-density of abundant predatory carabid beetles, which are considered important natural control agents of agricultural pests, was observed to increase at rising temperature. The pollen beetle Meligethes aeneus is one of the most important insect pests in European oilseed rape fields, and its larvae were observed to be important prey to carabid beetles. Therefore, we performed a laboratory experiment to detect whether rising temperature affects the number of pollen beetle larvae killed by five abundant carabids, and larval biomass ingested by carabids. In three climate chambers actual temperature (T1) was compared to temperatures increased by 3 °C (T2) and 5 °C (T3). This is the first study investigating the feeding of carabid predators on an arable pest insect spanning a realistic forecasted climate warming scenario of 3 and 5 °C, thus providing basic knowledge on that neglected research area. We hypothesized that carabids kill more pollen beetle larvae at rising temperature, and biomass intake by carabids increases with rising temperature. RESULTS: Both beetle species and temperature had significant effects on the number of killed Meligethes larvae and larval biomass ingested by carabids. Amara ovata, Harpalus distinguendus and Poecilus cupreus killed significantly more pollen beetle larvae at T2 and T3 compared to T1. Anchomenus dorsalis killed significantly more larvae at T2 than T1, and Harpalus affinis showed no significant differences among temperatures. Biomass intake by A. ovata, H. distinguendus and A. dorsalis was significantly larger at T2 and T3 compared to T1. Biomass intake by H. affinis and P. cupreus did not significantly differ among temperatures. Among the five carabids tested P. cupreus exhibited the highest values for both number of killed larvae and biomass intake. CONCLUSIONS: Our lab results suggest a clear potential for higher feeding of pollen beetle larvae by carabid beetles at rising temperature. As rising temperature leads to increased activity of abundant arable carabids in the field, it may be expected that there is enhanced pest suppression under warmer field conditions.

Diel variations in the assemblage structure and foraging ecology of larval and 0+ year juvenile fishes in a man-made floodplain waterbody.

This study investigated diel variations in zooplankton composition and abundance, and the species composition, density, size structure, feeding activity, diet composition and prey selection of larval and 0+ year juvenile fishes in the littoral of a man-made floodplain waterbody over five 24 h periods within a 57 day period. There was a significant difference in the species composition of diurnal and nocturnal catches, with most species consistently peaking in abundance either during daylight or at night, reflecting their main activity period. There were no consistent diel patterns in assemblage structure or the abundance of some species, however, most likely, respectively, due to the phenology of fish hatching and ontogenetic shifts in diel behaviour or habitat use. There were few clear diel patterns in the diet composition or prey selection of larval and 0+ year juvenile roach Rutilus rutilus and perch Perca fluviatilis, with most taxa consistently selected or avoided irrespective of the time of day or night, and no obvious shift between planktonic and benthic food sources, but dietary overlap suggested that interspecific interactions were probably strongest at night. It is essential that sampling programmes account for the diel ecology of the target species, as diurnal surveys alone could produce inaccurate assessments of resource use. The relative lack of consistent diel patterns in this study suggests that multiple 24 h surveys are required in late spring and early summer to provide accurate assessments of 0+ year fish assemblage structure and foraging ecology.

Variation in outcomes of the Melbourne Infant, Feeding, Activity and Nutrition Trial (InFANT) Program according to maternal education and age.

OBJECTIVE: To assess the effectiveness of the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program according to maternal education and age. METHODS: A cluster-randomised controlled trial involving 542 mother/infant pairs from 62 existing first-time parent groups was conducted in 2008 in Melbourne, Australia. The intervention involved 6 × 2-hour dietitian-delivered sessions, DVD and written resources from infant age 4-15 months. Outcomes included infant diet (3 × 24 h diet recalls), physical activity (accelerometry), television viewing and body mass index. We tested for moderation by maternal education (with/without a University degree) and age (< 32 and ≥ 32 years). The trial was registered with the ISRCTN Register (identifier 81847050). RESULTS: Interaction effects with the treatment arm were observed for maternal education and age. The intervention effects on vegetable (positive effect) and sweet snack consumption (negative effect) were greater in children with higher educated mothers while intervention effects on water consumption (positive effect) were greater in infants with lower educated mothers. The intervention was also more effective in increasing both vegetable and water consumption in infants with mothers aged < 32 years. CONCLUSIONS: Child obesity prevention interventions may be differentially effective according to maternal education and age. Evidence of differential effects is important for informing more sensitively targeted/tailored approaches.

Time-place learning and leader-follower relationships in Arctic charr Salvelinus alpinus.

Feeding activity from a larger refuge site into two visually separated feeding sites with temporally restricted food availability, one in the morning and one in the evening was studied in duplicate groups of Arctic charr Salvelinus alpinus. A passive integrated transponder (PIT) system enabled continuous monitoring of individual movements between the sites. Both groups synchronized their diel pattern of visit activity to the two feeding sites when food was available. One group showed significant anticipatory visit activity into both feeding sites during the hours before the feed was available, suggesting a time and place learning of resource availability. The anticipatory activity of the other group was, however, less pronounced and only occurred into one of the feeding sites. Individual S. alpinus entered the feeding sites independently and no obvious patterns of leaders and followers were identified. All S. alpinus gained mass and moved between a refuge and the feeding sites. Different strategies of how individual S. alpinus utilized the feeding sites were not correlated with growth.

Leptin gene expression in the brain is associated with the physiological onset of estivation in western sand lance Ammodytes japonicus.

Dormancy is an essential ecological characteristic for the survival of organisms that experience harsh environments. Although factors that initiate dormancy vary, suppression or cessation of feeding activities are common among taxa. To distinguish between extrinsic and intrinsic causes of metabolic reduction, we focused on estivation, which occurs in summer when the feeding activity is generally enhanced. Sand lances (genus Ammodytes) are a unique marine fish with a long estivation period from early summer to late autumn. In the present study, we aimed to elucidate the control mechanisms of estivation in western sand lance (A. japonicus), and firstly examined behavioral changes in 8 months including a transition between active and dormant phases. We found that swimming/feeding behavior gradually decreased from June, and completely disappeared by late August, indicating all individuals had entered estivation. Next, we focused on leptin, known as a feeding suppression hormone in various organisms, and examined leptin-A gene (AjLepA) expression in the brain that may regulate the seasonal behavioral pattern. AjLepA expression decreased after 7 days of fasting, suggesting that leptin has a function to regulate feeding in this species. The monthly expression dynamics of AjLepA during the feeding (active) and non-feeding (estivation) periods showed that the levels gradually increased with the onset of estivation and reached its peak when all the experimental fish had estivated. The present study suggests that the suppression of feeding activity by leptin causes shift in the physiological modes of A. japonicus before estivation.

Pyrifluquinazon baseline susceptibility and inhibition of Tomato chlorosis virus transmission by Bemisia tabaci.

BACKGROUND: Tomato chlorosis virus (ToCV) is associated with tomato yellow leaf disorder diseases in more than 20 countries. ToCV can be transmitted in a semipersistent manner by whitefly vectors such as Bemisia tabaci. Controlling the vector pests by using chemical insecticides is an efficient and effective approach to reduce and interrupt the virus transmission. Pyrifluquinazon is a new pyridine azomethine derivative, showing insecticidal toxicity to sucking pests by disturbing their feeding behavior. However, limited attention has been paid to the performance of pyrifluquinazon against B. tabaci and ToCV transmission. RESULT: This study showed the lethal concentration of 50% (LC50 ) values of pyrifluquinazon to 22 B. tabaci field populations ranged from 0.54 to 2.44 mg L-1 , and the baseline susceptibility of B. tabaci to pyrifluquinazon was 1.24 mg L-1 with a 95% confidence limit of 0.35-1.85 mg L-1 . Pyrifluquinazon and afidopyropen did not show cross-resistance to dinotefuran and pymetrozine in B. tabaci, which both inhibited the feeding activities of B. tabaci. The antifeedant concentration of 50% (AFC50 ) values at 48 h were 0.70 mg L-1 for pyrifluquinazon and 2.13 mg L-1 for afidopyropen. Foliar application of pyrifluquinazon and afidopyropen reduced the ToCV transmission by 40.91% and 33.33%, respectively and significantly decreased the ToCV loads in tomato plants under laboratory conditions. CONCLUSION: These results provided new information about the effects of modulators of the vanilloid-type transient receptor potential channel on the toxicity to B. tabaci and inhibition of ToCV transmission. © 2023 Society of Chemical Industry.

Effects of artificial light at night on the feeding behaviour of three marine benthic grazers from the Adriatic Sea are species-specific and mostly short-lived.

Artificial light at night (ALAN) has the potential to change the day-night activity of marine benthic grazers, and can therefore alter the top-down control they exert on macroalgal communities. In laboratory experiments, we investigated the influence of three realistic ALAN regimes on food consumption and feeding rhythmicity in the sea urchins Arbacia lixula and Paracentrotus lividus as well as in the snail Cerithium spp. from the Adriatic Sea. Food consumption was assessed in assays with algal pellets, while feeding rhythms were documented with 24 h time-lapse photography. Both was done in ALAN-acclimated and in non-acclimated animals. We observed temporary and potential long-term changes in the feeding rhythms of Cerithium spp. and Paracentrotus lividus, respectively, but found no lasting influence of ALAN on consumption rates. Effects were weaker when ALAN was applied only part-night, which suggests a possible mitigation measure to reduce the impact of nighttime lighting on coastal ecosystems.

Symbiont-regulated serotonin biosynthesis modulates tick feeding activity.

Ticks are obligate hematophagous arthropods. Blood feeding ensures that ticks obtain nutrients essential for their survival, development, and reproduction while providing routes for pathogen transmission. However, the effectors that determine tick feeding activities remain poorly understood. Here, we demonstrate that reduced abundance of the symbiont Coxiella (CHI) in Haemaphysalis longicornis decreases blood intake. Providing tetracycline-treated ticks with the CHI-derived tryptophan precursor chorismate, tryptophan, or 5-hydroxytryptamine (5-HT; serotonin) restores the feeding defect. Mechanistically, CHI-derived chorismate increases tick 5-HT biosynthesis by stimulating the expression of aromatic amino acid decarboxylase (AAAD), which catalyzes the decarboxylation of 5-hydroxytryptophan (5-HTP) to 5-HT. The increased level of 5-HT in the synganglion and midgut promotes tick feeding. Inhibition of CHI chorismate biosynthesis by treating the colonized tick with the herbicide glyphosate suppresses blood-feeding behavior. Taken together, our results demonstrate an important function of the endosymbiont Coxiella in the regulation of tick 5-HT biosynthesis and feeding.

Are structural and functional endpoints of soil communities similarly affected by metal mixtures? - A terrestrial model ecosystem approach.

Soils are habitat to a variety of flora and fauna in a linked ecosystem which provides essential ecosystem services. In soil, metals can accumulate at high concentrations, because of anthropogenic activities, leading to toxic effects, threatening the ecosystem and the services it provides. In most real-world contamination scenarios, metals occur as complex mixtures which can interact and produce different toxicity than predicted from individual metal data. Current regulatory guidelines are based on single species responses to individual metals and ignore indirect effects inherent to the inter-linked nature of ecosystems. Also, the evaluation of anthropogenic impacts to the soil communities is usually measured through structural endpoints (e.g. abundance) disregarding functional measurements (e.g. organic matter decomposition rates), which are often seen as tightly related, and thus, similarly affected. In this study we tested three mixture ratios of five metal oxides (lead, copper, nickel, zinc, cobalt) at three dose levels (Low, Med, High) in a terrestrial model ecosystem experiment and measured structural and functional endpoints. Exposure to metal mixtures for 16 weeks did not affect the microarthropod community, but produced severe effects on soil microbial activity (PNR and DHA) reducing activity below 50% compared to control levels, in all dosed treatments. Metal contamination also significantly affected feeding activity and organic matter decomposition, but effects were not as pronounced as on microbial activity. Data suggest that, in the risk assessment of metals and their mixtures, effects on ecosystem structure and functions must be considered to provide adequate environmental protection.

Progestogen-induced alterations and their ecological relevance in different embryonic and adult behaviours of an invertebrate model species, the great pond snail (Lymnaea stagnalis).

The presence of oral contraceptives (basically applying estrogens and/or progestogens) poses a challenge to animals living in aquatic ecosystems and reflects a rapidly growing concern worldwide. However, there is still a lack in knowledge about the behavioural effects induced by progestogens on the non-target species including molluscs. In the present study, environmental progestogen concentrations were summarised. Knowing this data, we exposed a well-established invertebrate model species, the great pond snail (Lymnaea stagnalis) to relevant equi-concentrations (1, 10, 100, and 500 ng L-1) of mixtures of four progestogens (progesterone, drospirenone, gestodene, levonorgestrel) for 21 days. Significant alterations were observed in the embryonic development time, heart rate, feeding, and gliding activities of the embryos as well as in the feeding and locomotion activity of the adult specimens. All of the mixtures accelerated the embryonic development time and the gliding activity. Furthermore, the 10, 100, and 500 ng L-1 mixtures increased the heart rate and feeding activity of the embryos. The 10, 100, and 500 ng L-1 mixtures affected the feeding activity as well as the 1, 10, and 100 ng L-1 mixtures influenced the locomotion of the adult specimens. The differences of these adult behaviours showed a biphasic response to the progestogen exposure; however, they changed approximately in the opposite way. In case of feeding activity, this dose-response phenomenon can be identified as a hormesis response. Based on the authors' best knowledge, this is the first study to investigate the non-reproductive effects of progestogens occurring also in the environment on molluscan species. Our findings contribute to the global understanding of the effects of human progestogens, as these potential disruptors can influence the behavioural activities of non-target aquatic species. Future research should aim to understand the potential mechanisms (e.g., receptors, signal pathways) of progestogens induced behavioural alterations.

Plant Viruses Can Alter Aphid-Triggered Calcium Elevations in Infected Leaves.

Alighting aphids probe a new host plant by intracellular test punctures for suitability. These induce immediate calcium signals that emanate from the punctured sites and might be the first step in plant recognition of aphid feeding and the subsequent elicitation of plant defence responses. Calcium is also involved in the transmission of non-persistent plant viruses that are acquired by aphids during test punctures. Therefore, we wanted to determine whether viral infection alters calcium signalling. For this, calcium signals triggered by aphids were imaged on transgenic Arabidopsis plants expressing the cytosolic FRET-based calcium reporter YC3.6-NES and infected with the non-persistent viruses cauliflower mosaic (CaMV) and turnip mosaic (TuMV), or the persistent virus, turnip yellows (TuYV). Aphids were placed on infected leaves and calcium elevations were recorded by time-lapse fluorescence microscopy. Calcium signal velocities were significantly slower in plants infected with CaMV or TuMV and signal areas were smaller in CaMV-infected plants. Transmission tests using CaMV-infected Arabidopsis mutants impaired in pathogen perception or in the generation of calcium signals revealed no differences in transmission efficiency. A transcriptomic meta-analysis indicated significant changes in expression of receptor-like kinases in the BAK1 pathway as well as of calcium channels in CaMV- and TuMV-infected plants. Taken together, infection with CaMV and TuMV, but not with TuYV, impacts aphid-induced calcium signalling. This suggests that viruses can modify plant responses to aphids from the very first vector/host contact.

Effects of sediment-associated Cu on Tubifex tubifex - Insights gained by standard ecotoxicological and novel, but simple, bioturbation endpoints.

Sediments serve as both source and sink of contaminants (e.g., Cu) and biologically important materials (e.g., metals, nutrients). Bioturbation by benthic organisms is ecologically relevant as bioturbation affects the physio-chemical characteristics of sediments, thus altering nutrient and contaminant distribution and bioavailability. We examined the effects of sediment-associated Cu on T. tubifex with conventional toxicity endpoints, such as mortality and growth, and less commonly used non-destructive endpoints, such as bioturbation and feeding. An experimental approach was developed to examine the applicability of simple methods to detect effects on bioturbation and feeding. Two experiments were conducted with 7-day exposures to uncontaminated or Cu-spiked natural sediment at six Cu concentrations to examine Cu bioaccumulation and effects. Endpoints included worm mortality, feeding rate and growth (experiment A) and worm bioturbation (particle diffusion and maximum penetration depth, experiment B). A microparticle tracer was placed on the sediment surface and vertical particle transport was followed over time. Adverse effects were detected for all endpoints (bioturbation, feeding rate, growth and survival): a slight positive effect at the lowest Cu concentrations followed by adverse effects at higher concentrations indicating hormesis. These simple, non-destructive endpoints, provided valuable information and demonstrated that sediment-associated contaminants, such as Cu, can influence bioturbation activity, which in turn may affect the distribution of sediment-bound or particulate pollutants, such as the plastic microparticles studied here. Thus, we suggest to use simple endpoints, such as bioturbation and feeding rate, in ecotoxicity testing since these endpoint account for the influence of interactions between pollutants and benthos and, thus, increase ecological relevance.

Development of nocturnal feeding and photosensitivity in early juveniles of the warty sea cucumber Stichopus cf. horrens.

Behavioral responses to light of early life stages provide insights on the development of photosensitivity in nocturnal species such as Stichopus cf. horrens. In this study, the onset of nocturnal feeding behavior, growth, and survival during early juvenile development (0.56 ±â€¯0.16 cm; 47 days post-settlement) of the species were investigated for 30 days, in the presence (S) or absence (W) of artificial shelters and under three light regimes: constant light (24 L), constant dark (24D), and a 12 -h light, 12 -h dark period (12 L:12D). Juveniles in all treatments fed initially during daytime hours but eventually exhibited a shift to nocturnal feeding by day 11. This behavioral shift to nocturnality was delayed among individuals under constant dark conditions. Continuous light exposure without shelter resulted in low juvenile survival and mass mortality in some replicates of the treatment. In contrast, growth and survival were highest for juveniles in constant dark. This study showed the endogenous control of feeding in this species. It also demonstrated that growth increases significantly when early juveniles are reared with shelters or in constant dark. Optimizing the light regime and type of shelter can improve food accessibility and juvenile growth without hindering the development of photosensitivity in early juveniles. Further studies are needed to enhance the nursery culture of this species.

Ecotoxicity Assessment of Graphene Oxide by Daphnia magna through a Multimarker Approach from the Molecular to the Physiological Level including Behavioral Changes.

The extensive use of engineered nanomaterials, such as graphene oxide (GO), is stimulating research about its potential environmental impacts on the aquatic ecosystem. This study is aimed to comprehensively assess the acute toxicity of a well-characterized GO suspension to Daphnia magna. Conventional ecotoxicological endpoints (lethality, immobilization) and more sensitive, sublethal endpoints (heartbeat rate, feeding activity, and reactive oxygen species (ROS)) production were used. The possible normalization of the heartbeat rate and feeding activity in clean test medium was also investigated. The fate, time-dependent, and concentration-dependent aggregation behaviour of GO was followed by dynamic light scattering, UV-Vis spectroscopy, and zeta potential measurement methods. The EC20 value for immobilization was 50 mg/L, while, for physiological and behavioural endpoints, it ranged from 8.1 mg/L (feeding activity) to 14.8 mg/L (immobilization). The most sensitive endpoint was the ROS production with EC20 = 4.78 mg/L. 24-h recovery experiments revealed that feeding activity was restored only up to a certain level at higher concentrations, indicating that the potential environmental health effects of GO cannot be neglected. Alterations of normal physiology (heart rate) and feeding activity may be associated with increased risk of predation and reproductive decline, highlighting that GO may have impacts on population and food web dynamics in aquatic ecosystems.

Efficacy of Emamectin Benzoate Trunk Injection Against the Asian Long-Horned Beetle [Anoplophora glabripennis (Coleoptera: Cerambycidae)].

The efficacy of tree injected with emamectin benzoate (EB) against the Asian long-horned beetle (ALB) was tested in a heavily infested willow forest in Beijing, China. In a 1.7-ha plot, 240 out of 310 trees were treated with two EB formulations at various rates. After fall application, the larval population decreased by 89% in the following spring and by >99% during the second year detected by monitoring new frass emission from marked holes. Consequently, the number of exit holes of emerging adults decreased to 0 in the second year. Re-infestation occurred in the third year after application. This high efficacy and lasting activity might be contributed to: a) a favorable translocation of EB in trees when injected into the sapwood; b) the high intrinsic activity against ALB larvae with LC50 of 20-30 ppb; and c) a reduced lifespan of ALB adults by over 60% when feeding on twigs of EB-treated trees. On untreated control trees, the larval population decreased during the first winter. In the second year after application, the larval population was wiped out during winter and a re-infestation started from border trees by adults flying in from outside the trial plot. This pattern indicates an eradication of the ALB population in the 1.7-ha plot can be expected 2 yr after EB treatment. The benefit of treating with EB on the surrounding population was observed in both the untreated trees and imidacloprid-treated trees, suggesting that treatment of EB benefits both the treated trees and the surrounding trees in the area.