Analysis of sublethal responses in cold-stressed insects can provide important information about fitness costs and a better understanding of the physiological mechanisms used to prevent and/or to cope with cold injury. Yet, such responses are understudied and often neglected in the literature. Here, we analyzed the effects of cold stress applied to larvae on the mortality/survival and fitness parameters of survivor adults of the vinegar fly, Drosophila melanogaster. Third instar larvae (either cold-sensitive or cold-acclimated) were exposed to either supercooling or freezing stress, both at -5 °C. A whole array of sublethal effects were observed, from mortality that occurs with some delay after cold stress, through delayed development to the pupal stage, to shortened life-span of the adult, and decreased female fecundity. Taking the sublethal effects into account improves the ecological meaningfulness of cold hardiness assay outcomes. For instance, we observed that although more than 80% of cold-acclimated larvae survive freezing to -5 °C, less than 10% survive until adulthood, and survivor females exhibit more than 50% reduction in their fecundity relative to controls. Female fecundity was positively correlated with dry mass and negatively correlated with total protein and glycogen stores. Hence, these parameters may serve as good predictors of survivor adult female fecundity. Further, we provide the concept of a two-component defense system, which (based on analysis of sublethal effects on fitness parameters) distinguishes between physiological mechanisms that help insects to resist (reduce or avoid) or tolerate (survive or repair) injuries linked to cold stress.

• Keywords
• Fecundity, Fitness, Insect cold hardiness, Life-span, Resistance, Tolerance,
• MeSH
• Drosophila melanogaster growth & development   physiology   MeSH
• Stress, Physiological MeSH
• Genetic Fitness * MeSH
• Pupa physiology   MeSH
• Larva physiology   MeSH
• Cold Temperature MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Parasitoids acting as biocontrol agents provide farmers with valuable ecosystem services, but are sensitive to insecticides applied against pests. Besides lethal effects of insecticides, sublethal effects observed among survivors may further influence parasitoids' performance. However, information on sublethal effects is scattered across case studies, without a quantitative synthesis and evaluation of generality of respective data. We conducted an analysis of 85 primary empirical datasets to quantify sublethal effects of insecticide application on two key parameters of parasitoid fitness, offspring production and proportion of females among offspring (i.e. sex ratio). To create a direct link to existing agricultural practices, we primarily focused on studies in which parasitoids were exposed to field-recommended concentrations of insecticides. Insecticide-exposed females produced substantially fewer and more male-biased offspring, accounting for an average of about 28% cumulative loss in parasitoid reproductive capacity per generation. The magnitude of sublethal effects was significantly affected by insecticide mode of action, with broad-spectrum insecticides being particularly harmful to parasitoid reproductive performance. Transgenic crops and toxins derived from such plants were generally associated with weaker sublethal effects than majority of synthetic insecticides. Nevertheless, species responses, even to the same insecticides and transgenic crops, showed high variability, cautioning against extrapolating results from individual studies to a wider range of species. Overall, our results indicate that sublethal side-effects on parasitoid reproductive performance represent a significant and widespread cost of insecticides that should explicitly be taken into account when evaluating their harmfulness. Linking laboratory results to field situations remains a key challenge for future research.

• Keywords
• Biological control, Integrated pest management, Meta-analysis, Natural enemies, Non-target effects, Pesticides,
• MeSH
• Plants, Genetically Modified drug effects   growth & development   parasitology   MeSH
• Hymenoptera drug effects   growth & development   MeSH
• Insecticides toxicity   MeSH
• Host-Parasite Interactions drug effects   MeSH
• Lethal Dose 50 MeSH
• Reproduction * MeSH
• Sex Factors MeSH
• Crops, Agricultural drug effects   growth & development   parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Insecticides MeSH

OBJECTIVES: The causative agent of tularemia Francisella tularensis is highly infectious and lagomorphs are important reservoirs and a source of human disease. The aim of the present study was to test the hypothesis that sublethal exposure to pesticides increases the susceptibility of hares to F. tularensis and modulates the course of the infection. METHODS: Experimental hares were allocated to a) control, b) paraoxon-treated, c) F. tularensis-treated, and d) paraoxon-and-F. tularensis-treated groups of five specimens on a random basis and subcutaneously inoculated with a wild F. tularensis subsp. holarctica strain (a single dose of 9 × 108 CFU pro toto) and/or injected a sublethal dose of paraoxon (100 μg/kg). Group differences were evaluated using survival curves, oxidative stress responses as well as caspase-3 and acetylcholinesterase activities in whole blood samples collected on day 2 post exposure. RESULTS: The paraoxon-and-F. tularensis-treated group showed a rapid onset of clinical signs and all deaths occurred on days 2 and 3 post exposure. F. tularensis-inoculated hares survived from 3 to 10 days, while only one hare died on day 12 in the paraoxon-treated group. Survival curves in the three exposed groups were significantly different from the control and median survival in F. tularensis-inoculated and paraoxon-and-F. tularensis-treated hares amounted to 7 and 2 days, respectively. Compared with controls, significant responses included an eight- and seven-fold activation of caspase-3 in F. tularensis-inoculated and paraoxon-and-F. tularensis-treated hares, respectively, and a 1.5-fold decrease of blood acetylcholinesterase activities in the paraoxon-treated and paraoxon-and-F. tularensis-treated groups. There was a 1.3- to 1.4-fold decrease of the ferric reducing antioxidant power in blood of F. tularensis-inoculated hares and the paraoxon-and-F. tularensis-treated group, respectively. The blood lipid peroxidation levels were of no differences among the four experimental groups. CONCLUSIONS: Results of this study can help understand the pathogenesis of tularemia and mortality of hares in agricultural habitats. Use of anticholinesterase agents in agriculture can pose a threat of infectious disease outbreaks and higher mortality in wildlife populations.

• MeSH
• Acetylcholinesterase blood   metabolism   MeSH
• Survival Analysis MeSH
• Antioxidants metabolism   MeSH
• Cholinesterase Inhibitors toxicity   MeSH
• Francisella tularensis pathogenicity   physiology   MeSH
• Insecticides toxicity   MeSH
• Caspase 3 blood   metabolism   MeSH
• Random Allocation MeSH
• Paraoxon toxicity   MeSH
• Tularemia blood   mortality   pathology   MeSH
• Environmental Exposure MeSH
• Hares * MeSH
• Disease Reservoirs MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Acetylcholinesterase MeSH
• Antioxidants MeSH
• Cholinesterase Inhibitors MeSH
• Insecticides MeSH
• Caspase 3 MeSH
• Paraoxon MeSH

Understanding the lethal and sublethal impacts of pesticides on biocontrol agents is crucial for the successful implementation of integrated pest management (IPM) programs. This study investigated the sublethal effects of fenpyroximate, a broad-spectrum acaricide/insecticide, on the fitness of Scolothrips longicornis Priesner (Thysanoptera: Thripidae), a key predator of the two-spotted spider mite, in controlled laboratory environments. Adult predators were exposed to pesticide residues on leaf discs to estimate parameters of concentration-mortality response models for females and males and calculate median lethal concentration (LC50) as well as sublethal concentrations (LC10, LC20 and LC30) used in subsequent bioassays. The estimated LC50 values for female and male predators were 18.32 and 15.49 µg a.i./mL, respectively. Results of sublethal concentrations experiments did not reveal any significant impact on the development of each stage or the survival rate of S. longicornis juveniles compared to those in the control group. However, the longevity of adult males and females was significantly lower at all sublethal concentrations than in the control. Moreover, the fecundity decreased significantly at all sublethal concentration treatments. With one exception (LC10), both the adult preoviposition period and total preoviposition period increased with increasing sublethal concentrations compared to those of the control. The shortest oviposition period (9.30 days) was observed at the LC30. For the life table parameters of S. longicornis females treated with sublethal concentrations, a significant decrease was found in the intrinsic rate of increase, net reproductive rate and finite rate of increase, whereas the mean generation time in the LC10 treatment was lower than that in the other treatments. This underscores the imperative need to consider sublethal concentration effects of fenpyroximate in the strategic design and implementation of IPM systems.

• Keywords
• Tetranychus urticae, Acaricide, Demographic parameters, Predatory thrips, Side effects, Two-sex life table,
• MeSH
• Acaricides * toxicity   MeSH
• Benzoates MeSH
• Longevity drug effects   MeSH
• Propionates * toxicity   MeSH
• Pyrazoles * toxicity   MeSH
• Tetranychidae MeSH
• Thysanoptera * physiology   drug effects   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Letter MeSH
• Names of Substances
• Acaricides * MeSH
• Benzoates MeSH
• fenpyroximate MeSH Browser
• Propionates * MeSH
• Pyrazoles * MeSH

Spiders were recently shown to be adversely affected by field-realistic concentrations of a broad scale of neonicotinoid insecticides. Among the reported effects of neonicotinoids on invertebrates were declines in lipid biosynthesis and upregulation of β-oxidation, while vertebrate models suggest increased adipogenesis following treatment with neonicotinoids. Therefore, we hypothesized that there exists synergy between the effects of diet and concurrent exposure to field-realistic concentrations of neonicotinoid insecticides. To address this hypothesis, we fed first instars of the large wolf spider Hogna antelucana with two types of diets and exposed them to field-realistic concentrations of three formulations of neonicotinoids (thiamethoxam, thiacloprid and acetamiprid). We then measured the growth of the tested spiders; the lipid and protein content of their bodies; and their behavior, including ballooning, rappelling, and locomotor parameters. The two tested diets consisted of casein-treated and sucrose-treated Drosophila melanogaster. The dietary treatments affected the lipid and protein content of the spiders, their body weight and carapace length but did not affect any of the measured behavioral parameters. Surprisingly, we did not find any effects of acute exposure to neonicotinoid insecticides on the lipid or protein reserves of spiders. Exposure to neonicotinoids altered the behavior of the spiders as reported previously in other spider species; however, these effects were not affected by dietary treatments. Overall, the dietary treatments did not have any major synergy with acute exposure to field-realistic concentrations of neonicotinoid insecticides.

• MeSH
• Drosophila melanogaster drug effects   physiology   MeSH
• Insecticides toxicity   MeSH
• Lipids analysis   MeSH
• Neonicotinoids toxicity   MeSH
• Nutritional Status * MeSH
• Spiders drug effects   physiology   MeSH
• Arthropod Proteins metabolism   MeSH
• Body Weight MeSH
• Toxicity Tests methods   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Insecticides MeSH
• Lipids MeSH
• Neonicotinoids MeSH
• Arthropod Proteins MeSH

The aim of the experiment was to obtain new knowledge on the biological effectiveness of high-energy (300 MeV/nucleon) helium ions, which represent a part of the spectrum of cosmic rays. Male (CBA x C57BL)F1 mice, 4 months old, were exposed to a dose of 4 Gy helium ions (exposure rate 0.05 Gy/min). As a comparative standard irradiation the same dose of 4 Gy of 137Cs gamma-rays (exposure rate 0.07 Gy/min) was used. Material sampling was performed 6-8 h, 4 days and 9 days after irradiation for both experimental groups mentioned above. There were 7 animals in each group including the control group of non-irradiated mice. Eight basic hematological parameters of peripheral blood, bone marrow, spleen and thymus were studied. On day 4 after the irradiation with helium ions, the values of leukocyte counts in peripheral blood, bone marrow cellularity and spleen cellularity were reduced to about 10% of the respective control values while the decline after irradiation with gamma-rays amounted to about 50%. These and other results presented reflect a high relative biological effectiveness of 300 MeV/nucleon helium ions.

• MeSH
• Time Factors MeSH
• Radiation Dosage MeSH
• Erythrocytes radiation effects   MeSH
• Granulocytes radiation effects   MeSH
• Helium * MeSH
• Hematopoietic System radiation effects   MeSH
• Ions MeSH
• Cosmic Radiation * MeSH
• Leukocytes radiation effects   MeSH
• Lymphocytes radiation effects   MeSH
• Mice MeSH
• Relative Biological Effectiveness MeSH
• Spleen cytology   radiation effects   MeSH
• Thymus Gland radiation effects   MeSH
• Gamma Rays * MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Helium * MeSH
• Ions MeSH

The effect of long-term (30 days) exposure to PCZ (0.2, 50, and 500 microg l(-1)) on intestine-related biochemical markers in rainbow trout was investigated. Multiple biomarkers were measured, including digestive enzymes (proteolytic enzymes and amylase), antioxidant responses (TBARS, CP, SOD, CAT, GR and GPx) and energy metabolic parameters (RNA/DNA ratio, Na(+)-K(+)-ATPase). Exposure to 500 microg l(-1) PCZ led to significantly inhibited (p<0.01) proteolytic enzyme and amylase activity. Activities of the antioxidant enzymes SOD, CAT, and GPx gradually increased at lower PCZ concentrations (0.2 and 50 microg l(-1)). At the highest concentration (500 microg l(-1)), oxidative stress was apparent as significant higher (p<0.05) lipid peroxidation and protein carbonyls, associated with an inhibition of antioxidant enzymes activity. Moreover, energy metabolic parameters (RNA/DNA ratio, Na(+)-K(+)-ATPase) were significantly inhibited (p<0.01) in the intestines of fish exposed to 500 microg l(-1) PCZ, compared with controls. We suggest that long-term exposure to PCZ could result in several responses in intestine-related biochemical markers, which potentially could be used as indicators for monitoring residual PCZ present in the aquatic environment.

• MeSH
• Amylases metabolism   MeSH
• Antioxidants metabolism   MeSH
• Biomarkers analysis   MeSH
• Water Pollutants, Chemical pharmacology   MeSH
• Protein Carbonylation drug effects   MeSH
• Oncorhynchus mykiss metabolism   MeSH
• Oxidative Stress MeSH
• Lipid Peroxidation drug effects   MeSH
• Peptide Hydrolases metabolism   MeSH
• Intestines drug effects   MeSH
• Intestinal Mucosa metabolism   MeSH
• Triazoles pharmacology   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Amylases MeSH
• Antioxidants MeSH
• Biomarkers MeSH
• Water Pollutants, Chemical MeSH
• propiconazole MeSH Browser
• Peptide Hydrolases MeSH
• Triazoles MeSH

Propiconazole (PCZ), a triazole fungicide, is widely present in the aquatic environment, but little is known regarding its chronic toxicity in the fish brain. This study assessed the effects of long-term exposure to PCZ on the antioxidant defense system and Na(+)-K(+)-ATPase activity of rainbow trout brain. Fish were exposed to sublethal concentrations of PCZ (0.2, 50, and 500 microg/l) for 7, 20, and 30 days, respectively. Oxidative stress indices (reactive oxygen species, lipid peroxidation, and carbonyl protein) and antioxidant parameters (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and reduced glutathione) were measured, as well as Na(+)-K(+)-ATPase activity. Adaptive responses to PCZ-induced stress were observed at 7 days. With prolonged exposure, significantly higher levels of oxidative indices were indicative of oxidative stress, as also were the significant inhibition of antioxidant enzyme activity and reduced glutathione content. Na(+)-K(+)-ATPase activity was significantly inhibited after prolonged exposure. Chemometrics of all parameters by principal component analysis, enabled the separation of sampled individuals into four groups with 93.39% of total accumulated variance. A low level of oxidative stress can induce the adaptive responses of the antioxidant defense system, while prolonged exposure to PCZ may lead to serious oxidative damage in fish brain. We suggest that selected biochemical markers in fish brain could be used as potential biomarkers for monitoring residual fungicides present in the aquatic environments.

• MeSH
• Antioxidants metabolism   MeSH
• Time Factors MeSH
• Water Pollutants, Chemical administration & dosage   toxicity   MeSH
• Brain drug effects   enzymology   metabolism   MeSH
• Oncorhynchus mykiss physiology   MeSH
• Oxidative Stress drug effects   MeSH
• Fungicides, Industrial administration & dosage   toxicity   MeSH
• Sodium-Potassium-Exchanging ATPase metabolism   MeSH
• Triazoles administration & dosage   toxicity   MeSH
• Environmental Exposure adverse effects   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antioxidants MeSH
• Water Pollutants, Chemical MeSH
• propiconazole MeSH Browser
• Fungicides, Industrial MeSH
• Sodium-Potassium-Exchanging ATPase MeSH
• Triazoles MeSH

In addition to their active ingredients, pesticides contain also additives - surfactants. Use of surfactants has been increasing over the past decade, but their effects on non-target organisms, especially natural enemies of pests, have been studied only very rarely. The effect of three common agrochemical surfactants on the foraging behavior of the wolf spider Pardosa agrestis was studied in the laboratory. Differences in short-term, long-term, and overall cumulative predatory activities were investigated. We found that surfactant treatment significantly affected short-term predatory activity but had no effect on long-term predatory activity. The surfactants also significantly influenced the cumulative number of killed prey. We also found the sex-specific increase in cumulative kills after surfactants treatment. This is the first study showing that pesticide additives have a sublethal effect that can weaken the predatory activity of a potential biological control agent. More studies on the effects of surfactants are needed to understand how they affect beneficial organisms in agroecosystems.

• Keywords
• Agrochemicals, Foraging behavior, Pardosa, Spider, Surfactant,
• MeSH
• Agrochemicals chemistry   toxicity   MeSH
• Spiders drug effects   MeSH
• Pesticides chemistry   MeSH
• Surface-Active Agents toxicity   MeSH
• Predatory Behavior drug effects   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Agrochemicals MeSH
• Pesticides MeSH
• Surface-Active Agents MeSH

The effects of single (1 X 5 Gy) and repeated (4 X 5 Gy) gamma-ray doses, separated by 21 days, on femoral CFU-S numbers in mice during the 12 months after irradiation were compared. Nucleated cell and CFU-S numbers were recovered 21 days after whole-body irradiation with 5 Gy. Marrow regeneration was not sufficient after the second irradiation, and nucleated cell and CFU-S numbers reached 50% of the level of the control 21 days after the second dose. The decrease in CFU-S numbers was more marked after the third and fourth doses, reaching 35% of the control. While CFU-S numbers were recovered by the 21st day after a single dose of 5 Gy, the level of the control group was reached 60 days after the last dose of repeated (4 X 5 Gy) gamma irradiation. A decrease in femoral CFU-S numbers occurred in both irradiated groups 6 months after the last dose, the decrease having been more marked in the group exposed to repeated irradiations. The decrease was more pronounced 12 months after irradiation although bone marrow cellularity was at the level of the unirradiated group. Femoral CFU-S numbers were lower in unirradiated 480-day-old mice than in those at 120 days of age.

• MeSH
• Cell Division radiation effects   MeSH
• Time Factors MeSH
• Hematopoietic Stem Cells radiation effects   MeSH
• Mice, Inbred C57BL MeSH
• Mice, Inbred CBA MeSH
• Mice MeSH
• Age Factors MeSH
• Dose-Response Relationship, Radiation MeSH
• Gamma Rays MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH