The Colorado potato beetle (CPB; Leptinotarsa decemlineata) is an important potato pest with known resistance to pyrethroids and organophosphates in Czechia. Decreased efficacy of neonicotinoids has been observed in last decade. After the restriction of using chlorpyrifos, thiacloprid and thiamethoxam by EU regulation, growers seek for information about the resistance of CPB to used insecticides and recommended antiresistant strategies. The development of CPB resistance to selected insecticides was evaluated in bioassays in 69 local populations from Czechia in 2017-2022 and in 2007-2022 in small plot experiments in Zabcice in South Moravia. The mortality in each subpopulation in the bioassays was evaluated at the field-recommended rates of insecticides to estimate the 50% and 90% lethal concentrations (LC50 and LC90, respectively). High levels of CPB resistance to lambda-cyhalothrin and chlorpyrifos were demonstrated throughout Czechia, without significant changes between years and regions. The average mortality after application of the field-recommended rate of lambda-cyhalothrin was influenced by temperature before larvae were sampled for bioassays and decreased with increasing temperature in June. Downwards trends in the LC90 values of chlorpyrifos and the average mortality after application of the field-recommended rate of acetamiprid in the bioassay were recorded over a 6-year period. The baseline LC50 value (with 95% confidence limit) of 0.04 mg/L of chlorantraniliprole was established for Czech populations of CPBs for the purpose of resistance monitoring in the next years. Widespread resistance to pyrethroids, organophosphates and neonicotinoids was demonstrated, and changes in anti-resistant strategies to control CPBs were discussed.
- MeSH
- brouci * účinky léků MeSH
- dursban * farmakologie MeSH
- insekticidy * farmakologie MeSH
- larva účinky léků MeSH
- neonikotinoidy * farmakologie MeSH
- nitrily farmakologie MeSH
- pyrethriny farmakologie MeSH
- rezistence k insekticidům * MeSH
- Solanum tuberosum parazitologie MeSH
- thiamethoxam MeSH
- thiaziny * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- cyhalothrin MeSH Prohlížeč
- dursban * MeSH
- insekticidy * MeSH
- neonikotinoidy * MeSH
- nitrily MeSH
- pyrethriny MeSH
- thiacloprid MeSH Prohlížeč
- thiamethoxam MeSH
- thiaziny * MeSH
Despite several restrictions to their use, neonicotinoid insecticides are still widely employed worldwide. Residual sub-lethal amounts of these chemicals can have detrimental effects on the behavior of non-target insects. Toxic effects on economically important species such as bees have been widely documented, but less is known about their toxic action on other social insects, such as ants. In this study, we assessed the effect of different sub-lethal doses of the neonicotinoid imidacloprid on the ability of colonies of the invasive ant Lasius neglectus to select the most profitable resource. We used Y-shaped mazes having an imidacloprid-polluted or an unpolluted sucrose solution on the two branches. Two sucrose (0.1 M, 0.5 M) and two imidacloprid (1 μg/ml, 10 μg/ml) concentrations were used. In parallel, we evaluated the marking activity of foragers who fed on the same solutions. We found that the 0.1 M sugar solution polluted with 1 μg/ml imidacloprid was significantly more frequently selected in binary choices experiments than the unpolluted resource. Moreover, the ingestion of the same combination of sugar and imidacloprid significantly increased the marking rate of foragers. The higher concentration of the pollutant had lower effects, probably because of the hormesis phenomenon. Results suggest that the lower sub-lethal dose of imidacloprid can lead ants to select again the polluted resource. This "active" selection of the pollutant may magnify the negative effects on the colonies. Due to their ecological role, any impairment of ant survival or behavior may have detrimental cascade effects on the whole ecosystem.
- Klíčová slova
- Ants, Binary choice, Invasive species, Neonicotinoids, Resource selection, Symmetry breaking,
- MeSH
- dusíkaté sloučeniny toxicita MeSH
- ekosystém MeSH
- Formicidae * MeSH
- insekticidy * toxicita MeSH
- neonikotinoidy farmakologie MeSH
- preference v jídle MeSH
- sacharidy MeSH
- sacharosa MeSH
- včely MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- dusíkaté sloučeniny MeSH
- imidacloprid MeSH Prohlížeč
- insekticidy * MeSH
- neonikotinoidy MeSH
- sacharidy MeSH
- sacharosa MeSH
Neonicotinoid insecticides are increasingly recognized for their role as information disruptors by modifying the chemical communication system of insects and therefore decreasing the chances of reproduction in target insects. However, data from spiders are lacking. In the present study, we tested the responses of males of a common agrobiont spider, Pardosa agrestis, to the application of field-realistic concentration of acetamiprid, which was formulated as Mospilan, and trace amounts of thiacloprid, which was formulated as Biscaya. We applied fresh or 24-h-old residues of Mospilan or Biscaya to the males just prior to the experiment or treated only the surface of a tunnel containing female draglines. We evaluated the ability of the males to recognize female cues from female dragline silk in a Y-maze. The field-realistic, sublethal doses of Mospilan altered pheromone-guided behavior. The choice of the tunnel with female draglines by males was hampered by tarsal treatment of the males with 24 h-old residues of Mospilan. The mating dance display was commonly initiated in control males that came into contact with female draglines and was suppressed by the Mospilan treatments in all three experimental settings. Some males only initiated the mating dance but did not manage to complete it; this was particularly true for males that were treated tarsally with fresh Mospilan residues, as none of these males managed to complete the mating dance. All three experimental settings with Mospilan decreased the frequency of males that managed to both select the tunnel with female draglines and complete the mating dance. The responses to the low-dose Biscaya were much milder and the study was not sufficiently powered to confirm the effects of Biscaya; however, the surprisingly observed trends in responses to very low Biscaya concentrations call for further analyses of long-term effects of trace amounts of neonicotinoids on the pheromone-guided behavior of spiders. These are the first conclusive data regarding the effects of commercially available formulations of neonicotinoid insecticides on the intraspecific chemical communication of spiders.
- MeSH
- chemoreceptory účinky léků MeSH
- neonikotinoidy farmakologie MeSH
- pavouci účinky léků metabolismus fyziologie MeSH
- sexuální chování zvířat MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- neonikotinoidy MeSH
Neonicotinoid insecticides are associated with a decline in the diversity and distribution of bees and wasps (Hymenoptera: Aculeata). The effects of neonicotinoids on the metamorphosis of aculeates have never been addressed in detail; however, recent evidence suggests that neonicotinoids induce wing abnormalities. We hypothesized that the metamorphosis success of bees and wasps differs in response to contact exposure to field-realistic concentrations of neonicotinoid insecticides or in response to combined exposure to neonicotinoid insecticides and benzimidazole fungicides. We treated prepupae of the model crabronid wasp Pemphredon fabricii with field-realistic concentrations of four neonicotinoids, acetamiprid, imidacloprid, thiacloprid and thiamethoxam, and/or with the benzimidazole fungicide thiabendazole. Treatment with acetamiprid or imidacloprid decreased the pupation rates to only 39% and 32%, respectively. Treatment with thiacloprid or thiamethoxam did not affect the pupation rate when applied alone, but the subsequent treatment of thiacloprid- or thiamethoxam-treated prepupae with thiabendazole led to significant decreases in pupation rates. A high concentration of acetamiprid, which severely affected the pupation rates, had moderate effects on metamorphosis into adults, resulting in 53% metamorphosis success (as opposed to 95% metamorphosis success in the water-treated group). However, imidacloprid or thiamethoxam treatment resulted in only 5%-10% metamorphosis success into adults. Overall survival decreased in response to treatment with any of the neonicotinoids or benzimidazoles or their combinations, with extremely low survival (<2%) following combined treatment with imidacloprid and thiabendazole or thiamethoxam and thiabendazole. In conclusion, neonicotinoids alter insect metamorphosis success, which can be further potentiated by their combination with other agrochemicals, such as benzimidazoles.
- MeSH
- biologická proměna účinky léků MeSH
- insekticidy farmakologie MeSH
- kukla růst a vývoj MeSH
- neonikotinoidy farmakologie MeSH
- sršňovití růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- insekticidy MeSH
- neonikotinoidy MeSH
Agroecosystems are subject to regular disturbances that cause extinction or migration of much of their fauna, followed by recolonization from surrounding refuges. In small-sized aeronaut spiders, such recolonization is potentiated by their ability to rappel and balloon. These are complex behaviors that we hypothesized to be affected by neurotoxins, namely, neonicotinoids. We tested this hypothesis using two common farmland spider species, Oedothorax apicatus (Linyphiidae) and Phylloneta impressa (Theridiidae). The spiders were topically exposed by dorsal wet application or tarsal dry exposure to commercial neonicotinoid formulations Actara 25 WG, Biscaya 240 OD, Mospilan 20 SP and Confidor 200 OD at concentrations that are recommended for application in agriculture. Contact exposure to neonicotinoids suppressed the ability of spiders to produce the major ampullate fiber and anchor it to the substratum by piriform fibrils. Contact exposure to neonicotinoids also suppressed the ballooning behavior that was manifested by climbing to elevated places, adopting a tiptoe position and producing silk gossamer in the wind. Impaired ability of affected common farmland spiders to quickly recolonize disturbed agroecosystems by silk-mediated dispersal may explain their decline in multiple farmland ecosystems, in which neonicotinoids are applied.
- MeSH
- ekosystém * MeSH
- farmy * MeSH
- hedvábí metabolismus MeSH
- insekticidy farmakologie MeSH
- neonikotinoidy farmakologie MeSH
- pavouci metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hedvábí MeSH
- insekticidy MeSH
- neonikotinoidy MeSH
Synthetic chemical pesticides can enhance crop yields but also have undesired effects. Alternative 'botanical insecticides' may also have non-target effects on pollinators and biocontrol services. Employing action thresholds (ATs) can reduce pesticide (whether synthetic or botanical) use compared to fixed-interval applications. Here the azadirachtin-based botanical formulation NeemAzal and a neem seed extract (NSE) were evaluated in field spraying trials alongside commonly-used synthetics (Voliam Flexi [chlorentraniliprole plus thiamethoxam] and imidacloprid) in developing ATs for the regular and cosmopolitan cauliflower pests Brevicoryne brassicae, Plutella xylostella and Spodoptera litura. We considered the size of the S. litura larvae infesting the crop in order to derive ATs. ATs per plant were higher for NeemAzal (0.55 larvae for P. xylostella and 3 larvae for large-sized S. litura) than for Voliam Flexi (0.30 larvae for P. xylostella and 0.80 larvae for S. litura) but were similar for B. brassicae (50 individuals). Higher ATs when using azadirachtin were associated with the diverse modes of action of botanicals, for instance NeemAzal and NSE deterred oviposition of S. litura. Although the exact values of ATs are likely to have regional limits, our approach can be applied for determining ATs against common lepidopteran and aphid pests in many other vegetable crop agro-ecosystems.
- MeSH
- Brassica * MeSH
- druhová specificita MeSH
- dusíkaté sloučeniny farmakologie MeSH
- glyceridy farmakologie MeSH
- insekticidy chemická syntéza farmakologie MeSH
- larva účinky léků MeSH
- limoniny farmakologie MeSH
- mšice účinky léků MeSH
- můry účinky léků růst a vývoj MeSH
- neonikotinoidy farmakologie MeSH
- ovum účinky léků MeSH
- roční období MeSH
- terpeny farmakologie MeSH
- thiamethoxam farmakologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Indie MeSH
- Názvy látek
- azadirachtin MeSH Prohlížeč
- dusíkaté sloučeniny MeSH
- glyceridy MeSH
- imidacloprid MeSH Prohlížeč
- insekticidy MeSH
- limoniny MeSH
- neem oil MeSH Prohlížeč
- neonikotinoidy MeSH
- terpeny MeSH
- thiamethoxam MeSH
Neonicotinoids are very effective in controlling crop pests but have adverse effects on predators and pollinators. Spiders are less sensitive to neonicotinoids compared to insects because of the different structure of their acetylcholine receptors, the binding targets of neonicotinoids. We tested whether short-term exposure to neonicotinoids affected the predation rate in different densities of prey of spiders and led to their paralysis or eventual death. To examine these effects, we topically exposed dominant epigeic, epiphytic and sheet-weaving farmland spiders to four widely used neonicotinoids (imidacloprid, thiamethoxam, acetamiprid and thiacloprid). We applied the neonicotinoids at concentrations recommended by the manufacturers for spray application under field conditions. Short-term exposure to the formulations of all four tested neonicotinoids had adverse effects on the predation rate of spiders, with imidacloprid (Confidor) associated with the most severe effects on the predation rate and exhibiting partial acute lethality after one hour (15-32%). Acetamiprid also displayed strong sublethal effects, particularly when applied dorsally to Philodromus cespitum. Day-long exposure to dorsally applied acetamiprid or thiacloprid led to paralysis or death of multiple Linyphiidae spp., with the effects particularly prominent in males. To conclude, we provided multiple lines of evidence that short-term exposure to neonicotinoids, which were applied at recommended field concentrations, caused severe health effects or death in multiple families of spiders. Even acetamiprid caused strong effects, despite being subject to less strict regulations in the European Union, compared with those for imidacloprid because of claims of its negligible off-target toxicity.
- MeSH
- dusíkaté sloučeniny farmakologie MeSH
- insekticidy farmakologie MeSH
- neonikotinoidy farmakologie MeSH
- pavouci účinky léků MeSH
- predátorské chování účinky léků MeSH
- thiaziny farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- acetamiprid MeSH Prohlížeč
- dusíkaté sloučeniny MeSH
- imidacloprid MeSH Prohlížeč
- insekticidy MeSH
- neonikotinoidy MeSH
- thiacloprid MeSH Prohlížeč
- thiaziny MeSH
Determining the side effects of pesticides on pollinators is an important topic due to the increasing loss of pollinators. We aimed to determine the effects of chronic sublethal exposure of the neonicotinoid pesticide imidacloprid on the bumblebee Bombus terrestris under laboratory conditions. The analytical standard of imidacloprid in sugar solution was used for the treatment. Verification of pesticides using UHPLC-QqQ-MS/MS in the experimental bumblebees showed the presence of only two compounds, imidacloprid and imidacloprid-olefin, which were found in quantities of 0.57 ± 0.22 and 1.95 ± 0.43 ng/g, respectively. Thus, the level of the dangerous metabolite imidacloprid-olefin was 3.4-fold higher than that of imidacloprid. Label-free nanoLC-MS/MS quantitative proteomics of bumblebee heads enabled quantitative comparison of 2883 proteins, and 206 proteins were significantly influenced by the imidacloprid treatment. The next analysis revealed that the highly downregulated markers are members of the terpenoid backbone biosynthesis pathway (KEGG: bter00900) and that imidacloprid treatment suppressed the entire mevalonate pathway, fatty acid synthesis and associated markers. The proteomics results indicate that the consequences of imidacloprid treatment are complex, and the marker changes are associated with metabolic and neurological diseases and olfaction disruption. This study provides important markers and can help to explain the widely held assumptions from biological observations. SIGNIFICANCE: The major finding is that all markers of the mevalonate pathway were substantially downregulated due to the chronic imidacloprid exposure. The disbalance of mevalonate pathway has many important consequences. We suggest the mechanism associated with the novel toxicogenic effect of imidacloprid. The results are helpful to explain that imidacloprid impairs the cognitive functions and possesses the delayed and time cumulative effect.
- Klíčová slova
- Bombus terrestris, Endocrine disruptor, Imidacloprid-olefin, Pesticide exposure, Proteomics, Terpenoid backbone biosynthesis pathway,
- MeSH
- dusíkaté sloučeniny farmakologie MeSH
- insekticidy farmakologie MeSH
- kyselina mevalonová metabolismus MeSH
- mastné kyseliny biosyntéza MeSH
- neonikotinoidy farmakologie MeSH
- včely metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- dusíkaté sloučeniny MeSH
- imidacloprid MeSH Prohlížeč
- insekticidy MeSH
- kyselina mevalonová MeSH
- mastné kyseliny MeSH
- neonikotinoidy MeSH
A 2-year longitudinal study of enzyme-linked immunosorbent assay (ELISA) antibodies against Phlebotomus perniciosus and Phlebotomus papatasi (Diptera: Psychodidae) sandfly saliva was performed in 32 Beagle dogs treated preventively with an imidacloprid-permethrin topical insecticide in an endemic area in Spain. Dogs were grouped into three sandfly exposure groups according to the time of inclusion in the study. Assays analysed immunoglobulin G (IgG) against salivary gland homogenates (SGH) of both species and recombinant P. papatasi rSP32 and P. perniciosus rSP03B proteins in serum. The dogs were participating in a Leishmania infantum (Kinetoplastida: Trypanosomatidae) vaccine trial and were experimentally infected with the parasite in the second year. No dog acquired natural L. infantum infections during the first year, but most developed anti-saliva antibodies, and median log-transformed optical densities (LODs) were seasonal, mimicking those of local sandflies. This indicates that the repellent efficacy of the insecticide used is below 100%. Multi-level modelling of LODs revealed variability among dogs, autocorrelation and differences according to the salivary antigen and the dog's age. However, dog seroprevalence, estimated using pre-exposure LODs as cut-offs, was relatively low. This, and the fact that dogs did not become naturally infected with L. infantum, would support the efficacy and usefulness of this imidacloprid-permethrin topical insecticide in canine leishmaniasis control.
- Klíčová slova
- Antibodies, antigens, dogs, insecticides, saliva, sandfly,
- MeSH
- biologické markery krev MeSH
- dusíkaté sloučeniny aplikace a dávkování farmakologie MeSH
- kousnutí a bodnutí hmyzem prevence a kontrola MeSH
- longitudinální studie MeSH
- neonikotinoidy aplikace a dávkování farmakologie MeSH
- permethrin aplikace a dávkování farmakologie MeSH
- Phlebotomus účinky léků MeSH
- protilátky krev účinky léků MeSH
- psi imunologie MeSH
- repelenty proti hmyzu aplikace a dávkování farmakologie MeSH
- zvířata MeSH
- Check Tag
- psi imunologie MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Španělsko MeSH
- Názvy látek
- biologické markery MeSH
- dusíkaté sloučeniny MeSH
- imidacloprid MeSH Prohlížeč
- neonikotinoidy MeSH
- permethrin MeSH
- protilátky MeSH
- repelenty proti hmyzu MeSH
The Colorado potato beetle (CPB), Leptinotarsa decemlineata developed resistance to imidacloprid after exposure to this insecticide for multiple generations. Our previous studies showed that xenobiotic transcription factor, cap 'n' collar isoform C (CncC) regulates the expression of multiple cytochrome P450 genes, which play essential roles in resistance to plant allelochemicals and insecticides. In this study, we sought to obtain a comprehensive picture of the genes regulated by CncC in imidacloprid-resistant CPB. We performed sequencing of RNA isolated from imidacloprid-resistant CPB treated with dsRNA targeting CncC or gene coding for green fluorescent protein (control). Comparative transcriptome analysis showed that CncC regulated the expression of 1798 genes, out of which 1499 genes were downregulated in CncC knockdown beetles. Interestingly, expression of 79% of imidacloprid induced P450 genes requires CncC. We performed quantitative real-time PCR to verify the reduction in the expression of 20 genes including those coding for detoxification enzymes (P450s, glutathione S-transferases, and esterases) and ABC transporters. The genes coding for ABC transporters are induced in insecticide resistant CPB and require CncC for their expression. Knockdown of genes coding for ABC transporters simultaneously or individually caused an increase in imidacloprid-induced mortality in resistant beetles confirming their contribution to insecticide resistance. These studies identified CncC as a transcription factor involved in regulation of genes responsible for imidacloprid resistance. Small molecule inhibitors of CncC or suppression of CncC by RNAi could provide effective synergists for pest control or management of insecticide resistance.
- Klíčová slova
- ABC transporter, Insecticide resistance, P450, RNA interference, RNA sequencing, Xenobiotic transcription factor,
- MeSH
- brouci * genetika metabolismus MeSH
- dusíkaté sloučeniny farmakologie MeSH
- hmyzí geny fyziologie MeSH
- hmyzí proteiny * genetika metabolismus MeSH
- léková rezistence * účinky léků genetika MeSH
- neonikotinoidy farmakologie MeSH
- transkripční faktory * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- dusíkaté sloučeniny MeSH
- hmyzí proteiny * MeSH
- imidacloprid MeSH Prohlížeč
- neonikotinoidy MeSH
- transkripční faktory * MeSH