Effects Of Sublethal Concentrations Research Articles

Sublethal Effects of Spirotetramat, Cyantraniliprole, and Pymetrozine on Aphis gossypii (Hemiptera: Aphididae).

The toxicity and sublethal effects of three insecticides (spirotetramat, cyantraniliprole, and pymetrozine) on Aphis gossypii, a major agricultural pest, were investigated. The nymphal stage showed greater susceptibility than the adult stage to all the insecticides, with a difference of up to 8.9 times at the LC50 of spirotetramat. The effects of sublethal concentrations (LC10, LC30, LC50, and LC70) of the insecticides on the on the developmental period, survival rate, adult longevity, fecundity, and deformity rate were compared with those of the control. Compared with the control, cyantraniliprole and pymetrozine did not significantly affect the developmental period in the parental or F1 generation when applied at the nymphal stage at any concentration. Nonviable nymphs occurred in the F1 generation when both nymphs and adults were treated with spirotetramat and cyantraniliprole but not in the F2 generation. The age-specific maternity (lxmx) of A. gossypii treated with sublethal concentrations (LC10, LC30) decreased with increasing concentration. Spirotetramat at the LC30 resulted in significant differences in all life table parameters (R0, rm, λ, T, DT) compared with those of the control. Similarly, compared with that of the control (43.8), the net reproductive rate (R0) significantly decreased for all the insecticides except cyantraniliprole at the LC10 (37.5). Therefore, this study indicated that sublethal concentrations (over the LC30) of spirotetramat, cyantraniliprole, or pymetrozine might be useful for the density management of A. gossypii.

Impacts of the insecticide thiamethoxam on the native stingless bee Plebeia catamarcensis (Hymenoptera, Apidae, Meliponini)

Agricultural production and the indiscriminate use of insecticides such as thiamethoxam have put at risk the biodiversity and ecosystem services provided by bees, including native stingless species. Since most of the native species do not present economic importance, they may suffer “silent extinction”, due to lack of monitoring of their colonies. Therefore, this study aimed to determine the lethal and sublethal concentrations of the insecticide thiamethoxam, with evaluation of its sublethal effects on mobility, in the stingless bee Plebeia catamarcensis (Holmberg, 1903). Foraging bees were collected and exposed to thiamethoxam to determine lethal (LC50) and sublethal concentrations. The 24 h LC50 was 0.408 ng a.i./μL, a value demonstrating that this species may be as sensitive as other stingless bees already studied. Sublethal concentrations influenced the locomotion abilities of the bees, making them hyperactive when exposed to LC50/10 and lethargic when exposed to LC50/100. The effects of sublethal concentrations on individuals may have collective consequences, especially in colonies with few individuals, as is the case of P. catamarcensis. The findings reinforce the hypothesis that thiamethoxam may contribute to the decline of native stingless bees, which can be significantly impacted when chronically exposed to agricultural production systems that use this insecticide, consequently affecting the ecosystem services provided by these bees.

Cyantraniliprole seed treatment effectively controls wireworms (Pleonomus canaliculatus Faldermann) and white grubs (Anomala corpulenta Motschulsky) in maize fields

Wireworms and white grubs are destructive underground pests in maize fields in China. Cyantraniliprole has good control effect on coleoptera pests. Here, we evaluated the toxicity of cyantraniliprole to the second instar larvae of Anomala corpulenta Motschulsky and third-instar of larvae of Pleonomus canaliculatus Faldermann and the effects of sublethal concentrations on the activity of antioxidant and detoxification enzymes. We also explored the efficacy of cyantraniliprole on underground pests under indoor and field conditions. The LC50 of cyantraniliprole for the third instar larvae of P. canaliculatus was 23.3712 mg/L, and that for the second instar larvae of A. corpulenta was 5.9715 mg/L. Cyantraniliprole can activate the activity of superoxide dismutase (SOD), peroxidase (POD), and glutathione S-transferase (GST) to different degrees at a sublethal dose. According to the pot experiment and the control efficacy test in the field, the indoor control effect of cyantraniliprole seed treatment on P. canaliculatus and white grubs was approximately 80%, and the maximum increase in yield achieved through cyantraniliprole application was approximately 15% in the field efficacy test. Cyantraniliprole has a strong control effect on wireworms and white grubs, so it can be used to treat seeds to control underground pests in maize fields.

Effect of sub lethal concentrations of textile bleaching effluent in the total protein content in the fish, Cyprinus carpio

Proteins can be expected to be involved in the compensatory mechanism of stressed organisms. Toxic effect of treated textile bleaching effluent on the fish Cyprinus carpiowas assessed. Alteration in the protein content in muscle, liver, gill and intestine was determined after exposure to sublethal concentrations of the effluent for a period of 28 days. Data showed that total protein content was decreased in all test tissues compared to control. Results indicated the toxic nature of the effluent.

ACUTE TOXICITY, OXIDATIVE STRESS AND DAMAGES TO GILLS OF CARDIOSOMA ARMATUM (RAINBOW CRAB) INDUCED BY EXPOSURE TO PESTICIDES (DICHLORVOS AND CYPERMETHRIN)

The relative acute toxicity of Dichlorvos and Cypermethrin acting singly against Rainbow crab, Cardiosoma armatum was evaluated. The effects of sub lethal concentrations of the pesticides on the oxidative responses and histopathological effects in the gills of the crab were also investigated over a 30 days period. On the basis of 96 hrs LC50 value, Dichlorvos with 96 hr LC50 of 8.86 ?g/L was 2 times more toxic to the crabs than Cypermethrin with 96 hr LC50 of 17.80 ?g/L. The exposures to sub lethal concentrations (1/10th and 1/100th 96 hr LC50) of both pesticides each resulted in increase in the levels of lipid peroxidation product, malondialdehyde (MDA) in the gills compared to the control group at both day 15 and 30 of the bioassay . Super oxide dismutase (SOD) activity was inhibited by day 30 relative to control for both pesticides but the activities of Catalase (CAT) did not show a significant trend (P > 0.05). Exposure to sub lethal concentration (1/10th and 1/100th LC50) of both pesticides resulted in various histopathological effects such as curved filaments, fused filaments, epithelial lifting, congestion and odema. The damages to the gills were more severe in those exposed to Dichlorvous. The findings from this study indicates that both pesticides are potential threats to non- target rainbow crab populations and there is a risk of bioaccumulation and transport in the food chain under sub lethal exposures

Study on the effect of sublethal concentrations of antimicrobials on the growth and development of probiotic lactobacilli

The objective of this study was to investigate the effect of sublethal concentrations of 5 antibiotics (tetracycline, erythromycin, penicillin G, lincomycin, ciprofloxacin) and 2 preservatives (benzoic and sorbic acid) on the growth and development of 8 probiotic Lactobacillus strains. All lactobacilli were subjected to a large range of concentrations, growth curves were plotted and MICs were determined for each antimicrobial. The results showed correlation between the sublethal concentrations and the growth rate of the studied microorganisms. Based on the obtained data two groups of strains could be defined – sensitive and relatively resistant. The first group includes L. bulgaricus S2. L. bulgaricus S4. L. bulgaricus S19 and L. gasseri S20. The most resistant of this group was L. gasseri S20. The second group showed more sensitivity and the most affected by the antimicrobials was L. bulgaricus S28.

Effects of essential oil components exposure on biological parameters of Caenorhabditis elegans

The extensive use of essential oil components in an increasing number of applications can substantially enhance exposure to these compounds, which leads to potential health and environmental hazards. This work aimed to evaluate the toxicity of four widely used essential oil components (carvacrol, eugenol, thymol, vanillin) using the in vivo model Caenorhabditis elegans. For this purpose, the LC50 value of acute exposure to these components was first established; then the effect of sublethal concentrations on nematodes’ locomotion behaviour, reproduction, heat and oxidative stress resistance and chemotaxis was evaluated. The results showed that all the components had a concentration-dependent effect on nematode survival at moderate to high concentrations. Carvacrol and thymol were the two most toxic compounds, while vanillin had the mildest toxicological effect. Reproduction resulted in a more sensitive endpoint than lethality to evaluate toxicity. Only pre-exposure to carvacrol and eugenol at the highest tested sublethal concentrations conferred worms oxidative stress resistance. However, at these and lower concentrations, both components induced reproductive toxicity. Our results evidence that these compounds can be toxic at lower doses than those required for their biological action. These findings highlight the need for a specific toxicological assessment of every EOC application.

Impact of Cymbopogon flexuosus (Poaceae) essential oil and primary components on the eclosion and larval development of Aedes aegypti

The current study describes the effects of sub-lethal concentrations and constituent compounds (citral and geranyl acetate) of Cymbopogon flexuosus essential oil (EO) on the development of Aedes aegypti. We treated eggs with 6, 18, or 30 mg L−1 and larvae with 3 or 6 mg L−1 of EO and its major compounds (citral and geranyl acetate). Citral and geranyl acetate were evaluated at 18, 30, and 42 mg L−1 and compared with commercial growth inhibitors (diflubenzuron and methoprene). We measured larval head diameter, siphon length, and larval length. Finally, we examined concentrations of molt hormone (MH) and juvenile hormone III (JH III) using high-performance liquid chromatography coupled to mass spectrometry. All geranyl acetate concentrations decreased egg hatching, while EO altered molting among larval instars and between larvae and pupae, with an increase in the larval length (3 mg L−1: 6 ± 0.0 mm; 6 mg L−1: 6 ± 0.7 mm) and head width (3 mg L−1: 0.8 ± 0 mm; 6 mg L−1: 0.8 ± 0.0 mm) compared with the control group. We did not detect chromatographic signals of MH and JH III in larvae treated with C. flexuosus EO or their major compounds. The sub-lethal concentrations C. flexuosus EO caused a similar effect to diflubenzuron, namely decreased hormone concentrations, an extended larval period, and death.

Effects of Chlorpyrifos Ethyl on Cholinesterase and Growth of Silver Barb (Barbonymus gonionotus)

Chlorpyrifos ethyl is a popular insecticide widely used in agriculture within the Vietnamese Mekong delta, including for rice farming. Here, local farmers often apply pesticides at very high rates which leads to contamination of the surrounding environment. Silver barb (Barbonymus gonionotus) is a fish species indigenous to the delta, which resides in a variety of water bodies and is also commonly cultivated in rice–fish systems. As a result, this species is at high risk of exposure to chlorpyrifos ethyl. This study aims to determine the lethal concentration (LC50) of chlorpyrifos ethyl, as well as the effects of sub-lethal concentrations on the activity of cholinesterase and growth of Silver barb. Lethal concentration testing was conducted in a static non-renewed system. Three concentrations of chlorpyrifos ethyl (1%, 10% and 20% LC50-96 h) were conducted in triplicate to assess the effects of chlorpyrifos ethyl on the brain cholinesterase (ChE) of fingerling fish for 15 days, and on their growth for 60 days. Results showed that chlorpyrifos ethyl was highly toxic to fingerling Silver barb with a LC50-96 h of 0.119 ppm. The lowest observed effect concentration (LOEC) was 1%LC50-96 h for ChE and 10%LC50-96 h for growth. No observed effect concentration (NOEC) of chlorpyrifos ethyl for growth was 1%LC50-96 h. The result from this study suggests that ChE activity is significantly inhibited at environmentally realistic concentrations in the Vietnamese Mekong delta and can be used as a biomarker of pesticide exposure. Further study in the rice fields as well as in the canals or rivers is required.

Effects of sodium fluoride and Ocimum sanctum extract on the lifespan and climbing ability of Drosophila melanogaster

BackgroundFluoride may induce oxidative stress and apoptosis. It may also lead to neurobehavioural defects including neuromuscular damage. The present study aimed to explore the effects of sub lethal concentrations of sodium fluoride (NaF) on the lifespan and climbing ability of Drosophila melanogaster. In total, 0.6 mg/L and 0.8 mg/L of NaF were selected as sublethal concentrations of NaF for the study. Lifespan was measured and climbing activity assay was performed.ResultsThe study showed significant decrease in lifespan of flies treated with fluoride. With increasing age, significant reduction in climbing activity was observed in flies treated with sodium fluoride as compared to normal (control) flies. Flies treated with tulsi (Ocimum sanctum) and NaF showed increase in lifespan and climbing activity as compared to those treated with NaF only. Lipid peroxidation assay showed significant increase in malondialdehyde (MDA) values in the flies treated with NaF as compared to control. The MDA values decreased significantly in flies treated with tulsi mixed with NaF.ConclusionsThe results indicate that exposure to sub lethal concentration of NaF may cause oxidative stress and affect the lifespan and climbing activity of D. melanogaster. Tulsi extract may help in reducing the impact of oxidative stress and toxicity caused by NaF.

Neonicotinoid-contaminated diet causes behavior changes in forager honey bees (Apis mellifera) that may reduce colony survival during late fall

Neonicotinoid insecticides are often detected in pollen and nectar, which are the main food resources for honey bees. Sub-lethal and chronic exposure to these insecticides may have a prolonged effect on honey bees who are solely dependent on the stored food inside of the hive during cold weather. Our study investigated the effects of sub-lethal concentrations of imidacloprid on late fall forager honey bees’ behavior by accessing their activity levels and walking performance after being fed ad libitum with six different concentrations (2—125 μg/kg) of imidacloprid-dosed syrup for up to 48 h in the laboratory. Numbers of honey bees that walked after being released into a UV light illuminated tunnel decreased significantly as dosages of neonicotinoid in their diet increased. However, their walking speeds were not significantly affected by imidacloprid. The behavioral changes we observed in honey bees chronically exposed to neonicotinoid via diet could negatively affect individual honey bee performance of hive duties and consequently, colony survival during cold weather.

Effect of Sublethal Dose of Dichlorvos on the Biochemical Parameters of African Catfish

The present study investigated the effects of sublethal concentrations of dichlorvos on liver marker enzymes (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase), acid phosphatase (ACP), serum total protein (STP), bilirubin, urea and creatinine in African Catfish (Clarias gariepinus) juveniles at sub acute period under laboratory conditions. A total of 90 juveniles of Clarias gariepinus with average weight and length of 200.15 ± 0.09g and 26.00 ± 0.00cm respectively were kept in three experimental groups of 30 per group in triplicate of 10 fishes. Groups 1 and 2 were exposed to dichlorvos at dosages of 21 and 43mg/l respectively and group 3 served as control for 15 experimental days. Analyses were carried out on days 1, 5, 10 and 15. From the results, there was no significant changes in the biochemical parameters tested on day 1 of the experiment but levels of the liver enzymes, ACP and bilirubin increased significantly (p<0.05) on other experimental days when compared with the control group. However, there was insignificant increase in the urea level and also a non-significant decrease in the creatinine and Serum total protein (STP) levels of the experimental groups when compared with the control group. From the analyses and observations made, we conclude that the administration of sublethal concentrations of dichlorvos to African catfish induced some damages to the liver which affected the levels of the liver enzymes and the increase in ACP level is indicative of carcinogenicity.

Effects of Sub Lethal Concentrations of Sodium Fluoride on Sperm Activity and on the level of Sex Hormones of Adult Male Albino Rats

In recent years, fluorosis caused many problems in humans and animals bodies. Dental fluorosis, skeletal fluorosis, bone fractures, decreased birth rates, adverse effects on the male genital system, like damaging the structure of testes and epididymis and loosing fertilization ability can be considered as good examples of fluorosis. Thus, the current study aimed to determine the toxicity of sodium fluoride (NaF) on the activity of sperm and the level of sex hormones including testosterone, follicle stimulating hormone, and luteinizing hormone. For achieving this purpose, thirty adult albino male rats, aged between 90-100 days, were divided randomly into two treated groups with 10 rats for each group which were treated with 150, 300 ppm of sodium fluoride,respectively. In addition, 10 rats were kept as a control group. Sodium fluoride was offered to the treated groups in the drinking water to evaluate the toxic effect of NaF on male reproductive system, sperm concentration, sperm motion, and sperm velocity compared with control group. The findings revealed a significant decrease in the sperm concentration, sperm count, sperm motion, sperm velocity and the level of sexual hormones in comparison with the control group. It can be concluded that NaF may reduce the efficiency of male reproductive system, and reduce the levels of sexual hormones in rats

Toxicity and effects of combined agrochemical in Scaptotrigona bipunctata bees

The commercial insecticide Fastac Duo is a combined insecticide, widely used in different crops, acting on insects, affecting both pests and pollinators, such as bees. In this study, the effects of sublethal concentrations of Fastac Duo in stingless bees Scaptotrigona bipunctata were evaluated. Worker forager bees were exposed to the insecticide and histochemical and morphological analyses were conducted after 24, 48 and 72 h of ingestion. Brain analysis of S. bipunctata revealed changes in the chromatin condensing state according to exposure time and insecticide concentration when compared to the control group. Morphological changes were observed in the midgut in all concentrations and exposure times, which may interfere in several physiological processes. In conclusion, although the concentrations used in the study did not cause high mortality, it induced changes in the internal morphology that can lead to changes in bee activity.

Effects of sub-lethal concentrations of corexit 9500® dispersant on growth and condition factor of juvenile Clarias gariepinus (Burchell 1822), Rivers state, Nigeria

The effects of sub-lethal concentrations of Corexit 9500 on growth and condition factor of juveniles of Clarias gariepinus was investigated after 21days, in 2018. 160 fishes were used as test organisms with a loading of 10/treatment and were exposed to 0.00, 0.0125, 0.025 and 0.05 ml/L concentrations of Corexit 9500. Treatments were in triplicate and Complete Randomised Design was adopted. The growth in length and weight of C. gariepinus was significantly higher in the control than the test treatments (P<0.05). The increase in weight of the control was significantly different from the three treatments. Temperature was not significantly different (P>0.05); however, the DO of control was significantly higher (P < 0.05) than that of the treatments, with the lowest DO in the 0.05ml/l treatment. pH was acidic for all treatments including the control but was more acidic with increasing concentration of Corexit 9500. The pH value for each treatment was significantly different (P<0.05). The conductivity was significantly different from each other (P<0.05) with higher values at the 0.025 ml/L concentrations. The condition factor (K) decreased with increasing toxicant concentration and was significantly different (P<0.05) at 0.0125ml/L and at Weeks 2 and 3 of 0.05 ml/L. Corexit 9500 dispersants should be appropriately assessed before deployment, and their use near fish breeding grounds should be avoided.
 Key words: Clarias gariepinus, dispersant, growth, physicochemical parameters, sub-lethal

Histopathological Alterations In Organs of Nile Tilapia Fingerlings Exposed To Sub-Lethal Concentrations of Aqueous Crude Leaves Extract of Desert Date

Background: Histopathological changes have been widely used as biomarkers in determining the effects of pollutants on fish. Leaves of Balanites aegyptiaca, a deep-rooted, evergreen or semi-deciduous, multi-branched, spiny tree have been reported to have pesticidal, anaesthetic and ichthyotoxic effects. This study sought to find out the effect of sub-lethal concentrations (5.00, 11.00, 21.00, 43.00, and 86.00 mg/L) of B. aegyptiaca on histopathology of gills, kidney, and liver of mixed-sex Oreochromis niloticus fingerlings Methods: A total of 120 O. niloticus fingerlings (mean weight 23±0.03 g and mean total length 12.50±0.39 cm) were exposed to aqueous crude leaves extract of B. aegyptiaca. The gills, kidney, and liver were excised and processed routinely for the elucidation of histopathological changes Results: Dose-dependent histopathological changes were observed in the three organs (gills, kidney and liver) of O. niloticus exposed to graded concentrations of B. aegyptiaca. Gills showed moderate to severe secondary lamellae fusion, desquamation, and primary lamellae congestion while the kidney displayed mild to severe renal tubular epithelial cell degeneration and necrosis as well as pigmentation of renal tissues. The liver showed varying degrees of histo-architectural alterations such as hepatocellular degeneration and necrosis, cellular infiltrations, kupffer cell proliferation, portal, and sinusoidal congestions Conclusion: Owing to these histological alterations in the gills, kidney, and liver observed in this study, prolonged exposure of fish to B. aegyptiaca should be discouraged to preserve fish diversity

Histological, microbiological, physicochemical and heavy metals evaluation of effluent from Kara Cow Market, Ogun State, Nigeria in guppy fish (<i>Poecilia reticulata</i>)

The Ogun River is a sink for untreated effluents discharged from the Kara Cow Market, Ogun State. In this study, microbiological, physicochemical and heavy metals evaluation were carried out on effluent from the market. Standard methods were utilised for the examination of physicochemical and microbiological parameters of the effluent. The histological effects of sublethal concentrations of the effluent were assessed in the gills, intestine and skin of Poecilia reticulata (guppy fish) over a period of 56 days following standard methods and international ethical guidelines. None of the physicochemical parameters were within the set limits by the National Environmental Standards and Enforcement Agency (NESREA) for effluent discharges into surface waters. Coliforms, pathogens and fungi were observed in the effluent with a total plate count of 2.14 x 107 cfu/mL. The median lethal concentration (96 h LC50) of the effluent to P. reticulata was 71.50 mL/L (7.15%). Histological alterations such as distorted mucosal architecture with shortening and widening of intestinal villi were observed in the intestine of exposed groups of P. reticulata at day 56. The observed adverse physicochemical parameters, histological alterations and pathogenic microbes may pose ecological and public health risks to aquatic organisms and humans respectively. It is recommended that an effluent treatment plant should be installed at the market to reduce the pollutants load of the effluent before discharge into the Ogun River.
 Keywords: Effluents; histological effects; Kara Market; Ogun River; physicochemical parameters; pathogenic microorganisms; Poecilia reticulate

Effects of sublethal and realistic concentrations of the commercial herbicide atrazine in Pacu (Piaractus mesopotamicus): Long-term exposure and recovery assays.

Background and Aim:The commercial formulations of the herbicide atrazine (cATZ) are widely employed in Brazilian agriculture, and, as a consequence, ATZ has been found at levels above that established by law in the river basins in Brazil. Although the toxicity of ATZ in fish is well documented, there are few studies on the recovery capacity after cATZ exposure. This work aimed to evaluate, using several biomarkers, the toxic effects of long-term exposure to the sublethal (3.57 mg/L) and nonlethal realistic (3.00 µg/L) cATZ concentrations followed by a recovery assay, in fingerlings of a Brazilian teleost, the Piaractus mesopotamicus (pacu).Materials and Methods:Pacu fingerlings were housed in glass tanks and divided into the following experimental groups (two tanks/group): Exposure control = EC, recovery control = RC, the sublethal groups exposed to 3.57 mg/L of cATZ, (sublethal exposure group = SLE and sublethal recovery group = SLR) and the nonlethal groups treated with 3.00 µg/L of cATZ (nonlethal exposure group = NLE and nonlethal recovery group = NLR). The exposure assay was semi-static with a duration of 30 days and the recovery assay (after cATZ withdrawal) lasted 14 days. Several biomarkers were evaluated in fingerlings from all groups: The swimming behavior, the body weight gain, the micronucleus formation and nuclear alterations in erythrocytes, and the hepatic and renal histopathology analyzed by qualitative and semi-quantitative morphological methods (using light and electron microscopy).Results:No significant difference in weight gain was observed among the groups after the exposure and recovery assays. The sublethal exposure induced impaired swimming movements, significant histopathological alterations, including necrosis in the liver and kidney, and a significant increase in the frequency of micronuclei in erythrocytes. The nonlethal exposure induced only subtle histopathological changes in the liver and kidney. After recovery assay, no genotoxic alteration was noted in pacu exposed to sublethal concentration, while the cATZ-induced kidney damage was partially reversed but not the hepatic injury.Conclusion:cATZ exhibits long-term toxic effects on pacu, even at relatively low concentrations, affecting mainly the liver and the kidney, and the effects of sublethal concentration are only partially reversed after cATZ withdrawal.

Effect of sub-lethal concentration of Cadmium and Lead on Oreochromis niloticous

Effect of sub-lethal concentration of Cadmium and Lead on Oreochromis niloticous

Lethal and sublethal effects of thiacloprid on Schizaphis graminum (Rondani) (Hemiptera: Aphididae) and its predator Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae)

Lethal effects of thiacloprid were determined on Schizaphis graminum (Rondani) and Hippodamia variegata (Goeze) at 27 ± 1 °C, 65 ± 10% RH, and 16:8 (L:D) h. The effect of sublethal concentrations (LC10 and LC30) was estimated by the International Organization for Biological Integrated Control (IOBC). The LC50 values of thiacloprid for H. variegata and S. graminum were 730.3 and 212.7 mg a.i.L−1, respectively. Both tested sublethal concentrations negatively affected the demography of H. variegata and S. graminum. The LC30 treatments had a higher negative effect on demographic parameters of both tested insects compared to the LC10 one. Based on the IOBC classification, the LC10 and LC30 treatments were found to be harmless for H. variegata and slightly harmful for S. graminum. Therefore, thiacloprid can be suggested to be used in cereal fields where S. graminum and its predators are active.