As an important guarantee for stable and bumper crops, chemical pesticides play an irreplaceable role in pest control. Neonicotinoids are the most important chemical pesticides in the world. They have been registered for use in China and more than 120 countries including the European Union, the United States, and Canada. The market share accounts for more than 25% of the world. It selectively controls nicotinic acetylcholinesterase receptors (nAChRs) in the insect nervous system, paralyzes the central nervous system and causes insect death, and has excellent control effects on Homoptera, Coleoptera, Lepidoptera, and even resistant target pests. As of September 2021, there are 12 neonicotinoid pesticides registered in my country, namely imidacloprid, thiamethoxam, acetamiprid, clothianidin, dinotefuran, nitenpyram, thiacloprid, sflufenamid There are more than 3,400 kinds of preparation products including nitrile, piperazine, chlorothiline, cycloploprid and fluoropyranone, among which compound preparations account for more than 31%. Amine, dinotefuran, nitenpyram and so on.
With the continuous large-scale investment of neonicotinoid insecticides in the agricultural ecological environment, a series of scientific problems such as target resistance, ecological risks, and human health have also become prominent. In 2018, the cotton aphid field population in Xinjiang region developed moderate and high levels of resistance to neonicotinoid insecticides, among which the resistance to imidacloprid, acetamiprid and thiamethoxam increased by 85.2-412 times and 221-777 times, respectively and 122 to 1,095 times. International studies on the drug resistance of Bemisia tabaci populations also pointed out that from 2007 to 2010, Bemisia tabaci showed high resistance to neonicotinoid pesticides, especially imidacloprid and thiacloprid. Secondly, neonicotinoid insecticides not only seriously affect the population density, feeding behavior, spatial dynamics and thermoregulation of bees, but also have a significant negative effect on the development and reproduction of earthworms. In addition, from 1994 to 2011, the detection rate of neonicotinoid pesticides in human urine increased significantly, indicating that the indirect intake and body accumulation of neonicotinoid pesticides increased year by year. Through microdialysis in the rat brain, it was found that clothianidin and thiamethoxam stress can induce the release of dopamine in rats, and thiacloprid can induce the increase of thyroid hormone levels in rat plasma. It is inferred that neonicotinoid pesticides can affect lactation Damage to the nervous and endocrine systems of animals. The in vitro model study of human bone marrow mesenchymal stem cells confirmed that nitenpyram can cause DNA damage and chromosomal aberrations, resulting in the increase of intracellular reactive oxygen species, which in turn affects osteogenic differentiation. Based on this, the Canadian Pest Management Agency (PMRA) initiated a re-evaluation process for some neonicotinoid insecticides, and the European Food Safety Authority (EFSA) also banned and restricted imidacloprid, thiamethoxam and clothianidin.
The compounding of different pesticides can not only delay the resistance of a single pesticide target and improve the pesticide activity, but also reduce the amount of pesticides and reduce the risk of environmental exposure, providing broad prospects for the mitigation of the above scientific problems and the sustainable application of pesticides. Therefore, this paper aims to describe the research on the compounding of neonicotinoid pesticides and other pesticides that are widely used in actual agricultural production, covering organophosphorus pesticides, carbamate pesticides, pyrethroids In order to provide scientific reference for the rational use and effective management of neonicotinoid pesticides.
1 Progress in compounding with organophosphorus pesticides
Organophosphorus pesticides are typical insecticides in early pest control in my country. They inhibit the activity of acetylcholinesterase and affect normal neurotransmission, leading to the death of pests. Organophosphorus pesticides have a long residual period, and the problems of ecological toxicity and human and animal safety are prominent. Combining them with neonicotinoid pesticides can effectively alleviate the above scientific problems. When the compound ratio of imidacloprid and typical organophosphorus pesticides malathion, chlorpyrifos and phoxim is 1:40-1:5, the control effect on leek maggots is better, and the co-toxicity coefficient can reach 122.6-338.6 (see Table 1). . Among them, the field control effect of imidacloprid and phoxim on rape aphids is as high as 90.7% to 95.3%, and the effective period is more than 7 months. At the same time, the compound preparation of imidacloprid and phoxim (the trade name of Diphimide) was applied at 900 g/hm2, and the control effect on rape aphids in the whole growth period was more than 90%. The compound preparation of thiamethoxam, acephate and chlorpyrifos has good insecticidal activity against cabbage, and the co-toxicity coefficient reaches 131.1 to 459.0. In addition, when the ratio of thiamethoxam and chlorpyrifos was 1:16, the half-lethal concentration (LC50 value) for S. striatellus was 8.0 mg/L, and the co-toxicity coefficient was 201.12; Excellent effect. When the compound ratio of nitenpyram and chlorpyrifos was 1∶30, it had a good synergistic effect on the control of white-backed planthopper, and the LC50 value was only 1.3 mg/L. The combination of cyclopentapyr, chlorpyrifos, triazophos, and dichlorvos has a good synergistic effect on the control of wheat aphids, cotton bollworm and flea beetle, and the co-toxicity coefficient is 134.0-280.0. When fluoropyranone and phoxim were mixed in a ratio of 1:4, the co-toxicity coefficient was 176.8, which showed an obvious synergistic effect on the control of 4-year-old leek maggots.
To sum up, neonicotinoid pesticides are often combined with organophosphorus pesticides such as malathion, chlorpyrifos, phoxim, acephate, triazophos, dichlorvos, etc. The control efficiency is improved, and the impact on the ecological environment is effectively reduced. It is recommended to further develop the compound preparation of neonicotinoid insecticides, phoxim and malathion, and further exert the control advantages of compound preparations.
2 Progress in compounding with carbamate pesticides
Carbamate pesticides are widely used in agriculture, forestry, and animal husbandry by inhibiting the activities of insect acetylcholinease and carboxylesterase, resulting in the accumulation of acetylcholine and carboxylesterase and killing insects. The period is short, and the problem of pest resistance is serious. The use period of carbamate pesticides can be extended by compounding with neonicotinoid pesticides. When imidacloprid and isoprocarb were used in the control of white-backed planthopper at a ratio of 7:400, the co-toxicity coefficient reached the highest, which was 638.1 (see Table 1). When the ratio of imidacloprid and iprocarb was 1∶16, the effect of controlling rice planthopper was the most obvious, the co-toxicity coefficient was 178.1, and the duration of effect was longer than that of single dose. The study also showed that the 13% microencapsulated suspension of thiamethoxam and carbosulfan had good control effect and safety on wheat aphids in the field. d increased from 97.7% to 98.6%. After 48% acetamiprid and carbosulfan dispersible oil suspension was applied at 36～60 g a.i./hm2, the control effect on cotton aphids was 87.1%～96.9%, and the effective period could reach 14 days, and the cotton Aphid natural enemies are safe.
To sum up, neonicotinoid insecticides are often compounded with isoprocarb, carbosulfan, etc., which can delay the resistance of target pests such as Bemisia tabaci and aphids, and can effectively prolong the duration of pesticides. , the control effect of the compound preparation is significantly better than that of the single agent, and it is widely used in actual agricultural production. However, it is necessary to be alert to carbosulfur, the degradation product of carbosulfan, which is highly toxic and has been banned in vegetable cultivation.
3 Progress in compounding with pyrethroid pesticides
Pyrethroid insecticides cause neurotransmission disorders by affecting sodium ion channels in nerve membranes, which in turn lead to the death of pests. Due to excessive investment, the detoxification and metabolism ability of pests is enhanced, the target sensitivity is reduced, and drug resistance is easily generated. Table 1 points out that the combination of imidacloprid and fenvalerate has better control effect on potato aphid, and the co-toxicity coefficient of 2:3 ratio reaches 276.8. The compound preparation of imidacloprid, thiamethoxam and etherethrin is an effective method to prevent the flooding of brown planthopper population, wherein imidacloprid and etherethrin are best mixed in a ratio of 5:1, thiamethoxam and etherethrin in a ratio of 7:1 The mixing is the best, and the co-toxicity coefficient is 174.3-188.7. The microcapsule suspension compound of 13% thiamethoxam and 9% beta-cyhalothrin has a significant synergistic effect, and the co-toxicity coefficient is 232, which is in the range of 123.6- Within the range of 169.5 g/hm2, the control effect on tobacco aphids can reach 90%, and it is the main compound pesticide for the control of tobacco pests. When clothianidin and beta-cyhalothrin were compounded at a ratio of 1:9, the co-toxicity coefficient for flea beetle was the highest (210.5), which delayed the occurrence of clothianidin resistance. When the ratios of acetamiprid to bifenthrin, beta-cypermethrin and fenvalerate were 1:2, 1:4 and 1:4, the co-toxicity coefficient was the highest, ranging from 409.0 to 630.6. When the ratios of thiamethoxam:bifenthrin, nitenpyram:beta-cyhalothrin were all 5:1, the co-toxicity coefficients were 414.0 and 706.0, respectively, and the combined control effect on aphids was the most significant. The control effect of clothianidin and beta-cyhalothrin mixture (LC50 value 1.4-4.1 mg/L) on melon aphid was significantly higher than that of single agent (LC50 value 42.7 mg/L), and the control effect at 7 days after treatment was higher than 92%.
At present, the compound technology of neonicotinoid pesticides and pyrethroid pesticides is relatively mature, and it is widely used in the prevention and control of diseases and insect pests in my country, which delays the target resistance of pyrethroid pesticides and reduces the neonicotinoid pesticides. high residual and off-target toxicity. In addition, the combined application of neonicotinoid insecticides with deltamethrin, butoxide, etc. can control Aedes aegypti and Anopheles gambiae, which are resistant to pyrethroid pesticides, and provide guidance for the prevention and control of sanitary pests worldwide. significance.
4 Progress in compounding with amide pesticides
Amide insecticides mainly inhibit the fish nitin receptors of insects, causing the insects to continue to contract and stiffen their muscles and die. The combination of neonicotinoid insecticides and their combination can alleviate pest resistance and prolong their life cycle. For the control of target pests, the co-toxicity coefficient was 121.0 to 183.0 (see Table 2). When thiamethoxam and chlorantraniliprole were mixed with 15∶11 to control the larvae of B. citricarpa, the highest co-toxicity coefficient was 157.9; thiamethoxam, clothianidin and nitenpyram were mixed with snailamide When the ratio was 10:1, the co-toxicity coefficient reached 170.2-194.1, and when the ratio of dinotefuran and spirulina was 1:1, the co-toxicity coefficient was the highest, and the control effect on N. lugens was remarkable. When the ratios of imidacloprid, clothianidin, dinotefuran and sflufenamid were 5:1, 5:1, 1:5 and 10:1, respectively, the control effect was the best, and the co-toxicity coefficient was the best. They were 245.5, 697.8, 198.6 and 403.8, respectively. The control effect against cotton aphid (7 days) could reach 92.4% to 98.1%, and the control effect against diamondback moth (7 days) could reach 91.9% to 96.8%, and the application potential was huge.
To sum up, the compounding of neonicotinoid and amide pesticides not only alleviates the drug resistance of target pests, but also reduces the amount of drug use, reduces the economic cost, and promotes the compatible development with the ecosystem environment. Amide pesticides are prominent in the control of resistant target pests, and have a good substitution effect for some pesticides with high toxicity and long residual period. The market share is gradually increasing, and they have broad development prospects in actual agricultural production.
5 Progress in compounding with benzoylurea pesticides
Benzoylurea insecticides are chitinase synthesis inhibitors, which destroy pests by affecting their normal development. It is not easy to produce cross-resistance with other kinds of pesticides, and can effectively control the target pests resistant to organophosphorus and pyrethroid pesticides. It is widely used in neonicotinoid pesticide formulations. It can be seen from Table 2: the combination of imidacloprid, thiamethoxam and diflubenzuron has a good synergistic effect on the control of leek larvae, and the effect is the best when thiamethoxam and diflubenzuron are compounded at 5:1. The poison factor is as high as 207.4. When the mixing ratio of clothianidin and flufenoxuron was 2:1, the co-toxicity coefficient against the larvae of the leek larvae was 176.5, and the control effect in the field reached 94.4%. The combination of cyclofenapyr and various benzoylurea pesticides such as polyflubenzuron and flufenoxuron has a good control effect on diamondback moth and rice leaf roller, with a co-toxicity coefficient of 100.7 to 228.9, which can effectively reduce the investment of pesticides quantity.
Compared with organophosphorus and pyrethroid pesticides, the combined application of neonicotinoid pesticides and benzoylurea pesticides is more in line with the development concept of green pesticides, which can effectively expand the control spectrum and reduce the input of pesticides. The ecological environment is also safer.
6 Progress in compounding with necrotoxin pesticides
Neretoxin insecticides are nicotinic acetylcholine receptor inhibitors, which can cause insect poisoning and death by inhibiting the normal transmission of neurotransmitters. Because of its wide application, no systemic suction and fumigation, it is easy to develop resistance. The control effect of the rice stem borer and tri stem borer populations that have developed resistance by compounding with neonicotinoid insecticides is good. Table 2 points out: when imidacloprid and insecticidal single are compounded in a ratio of 2:68, the control effect on the pests of Diploxin is the best, and the co-toxicity coefficient is 146.7. When the ratio of thiamethoxam and insecticidal single agent is 1:1, there is a significant synergistic effect on corn aphids, and the co-toxicity coefficient is 214.2. The control effect of 40% thiamethoxam·insecticide single suspension agent is still as high as the 15th day 93.0%～97.0%, long lasting effect, and safe for corn growth. The 50% imidacloprid·insecticide ring soluble powder has excellent control effect on the apple golden stripe moth, and the control effect is as high as 79.8% to 91.7% 15 days after the pest is in full bloom.
As an insecticide independently developed by my country, insecticide is sensitive to grasses, which limits its use to a certain extent. The combination of necrotoxin pesticides and neonicotinoid pesticides provides more control solutions for the control of target pests in actual production, and is also a good application case in the development journey of pesticide compounding.
7 Progress in compounding with heterocyclic pesticides
Heterocyclic pesticides are the most widely used and the largest number of organic pesticides in agricultural production, and most of them have a long residual period in the environment and are difficult to degrade. The compounding with neonicotinoid pesticides can effectively reduce the dosage of heterocyclic pesticides and reduce phytotoxicity, and the compounding of low-dose pesticides can play a synergistic effect. It can be seen from Table 3: when the compound ratio of imidacloprid and pymetrozine is 1:3, the co-toxicity coefficient reaches the highest 616.2; Planthopper control is both quick-acting and lasting. Imidacloprid, dinotefuran and thiacloprid were combined with mesylconazole respectively to control the larvae of the giant black gill beetle, the larvae of the small cutworm, and the ditch beetle. Thiacloprid, nitenpyram and chlorothiline were respectively combined with The combination of mesylconazole has excellent control effect on citrus psyllids. The combination of 7 neonicotinoid insecticides such as imidacloprid, thiamethoxam and chlorfenapyr had a synergistic effect on the control of leek maggots. When the compounding ratio of thiamethoxam and fipronil is 2:1-71:1, the co-toxicity coefficient is 152.2-519.2, the compounding ratio of thiamethoxam and chlorfenapyr is 217:1, and the co-toxicity coefficient is 857.4 , has obvious control effect on termites. The combination of thiamethoxam and fipronil as a seed treatment agent can effectively reduce the density of wheat pests in the field and protect crop seeds and germinated seedlings. When the mixed ratio of acetamiprid and fipronil was 1:10, the synergistic control of drug-resistant housefly was the most significant.
In summary, the heterocyclic pesticide compound preparations are mainly fungicides, including pyridines, pyrroles and pyrazoles. It is often used in agricultural production to dress seeds, improve the germination rate, and reduce pests and diseases. It is relatively safe for crops and non-target organisms. Heterocyclic pesticides, as combined preparations for the prevention and control of pests and diseases, have a good role in promoting the development of green agriculture, reflecting the advantages of saving time, labor, economy and increasing production.
8 Progress in compounding with biological pesticides and agricultural antibiotics
Biological pesticides and agricultural antibiotics are slow to take effect, have a short duration of effect, and are greatly affected by the environment. By compounding with neonicotinoid pesticides, they can play a good synergistic effect, expand the control spectrum, and also prolong the efficacy and improve the stability. It can be seen from Table 3 that the combination of imidacloprid and Beauveria bassiana or Metarhizium anisopliae increased the insecticidal activity by 60.0% and 50.6% respectively after 96 h compared with the use of Beauveria bassiana and Metarhizium anisopliae alone. The combination of thiamethoxam and Metarhizium anisopliae can effectively increase the overall mortality and fungal infection rate of bed bugs. Second, the combination of imidacloprid and Metarhizium anisopliae had a significant synergistic effect on the control of longhorned beetles, although the amount of fungal conidia was reduced. Mixed use of imidacloprid and nematodes can increase the infection rate of sandflies, thereby improving their field persistence and biological control potential. The combined use of 7 neonicotinoid pesticides and oxymatrine had good control effect on rice planthopper, and the co-toxicity coefficient was 123.2-173.0. In addition, the co-toxicity coefficient of clothianidin and abamectin in a 4:1 mixture to Bemisia tabaci was 171.3, and the synergy was significant. When the compound ratio of nitenpyram and abamectin was 1:4, the control effect on N. lugens for 7 days could reach 93.1%. When the ratio of clothianidin to spinosad was 5∶44, the control effect was the best against B. citricarpa adults, with a co-toxicity coefficient of 169.8, and no crossover between spinosad and most neonicotinoids was shown Resistant, combined with good control effect.
The joint control of biological pesticides is a hot spot in the development of green agriculture. Common Beauveria bassiana and Metarhizium anisopliae have good synergistic control effects with chemical agents. A single biological agent is easily affected by weather, and its efficacy is unstable. Compounding with neonicotinoid insecticides overcomes this shortcoming. While reducing the amount of chemical agents, it ensures the quick-acting and lasting effect of compounded preparations. The prevention and control spectrum has been expanded, and the environmental burden has been reduced. The compounding of biological pesticides and chemical pesticides provides a new idea for the development of green pesticides, and the application prospect is huge.
9 Progress in compounding with other pesticides
The combination of neonicotinoid pesticides and other pesticides also showed excellent control effects. It can be seen from Table 3 that when imidacloprid and thiamethoxam were combined with tebuconazole as seed treatment agents, the control effects on wheat aphid were excellent, and non-target Biosafety while improving seed germination rate. The compound preparation of imidacloprid, triazolone and dinconazole showed good effect in the control of wheat diseases and insect pests. %～99.1%. The combination of neonicotinoid insecticides and syringostrobin (1∶20～20∶1) has obvious synergistic effect on cotton aphid. When the mass ratio of thiamethoxam, dinotefuran, nitenpyram and penpyramid is 50:1-1:50, the co-toxicity coefficient is 129.0-186.0, which can effectively prevent and control piercing-sucking mouthpart pests. When the ratio of epoxifen and phenoxycarb was 1:4, the co-toxicity coefficient was 250.0, and the control effect on rice planthopper was the best. The combination of imidacloprid and amitimidine had obvious inhibitory effect on cotton aphid, and the synergy rate was the highest when imidacloprid was the lowest dose of LC10. When the mass ratio of thiamethoxam and spirotetramat was 10:30-30:10, the co-toxicity coefficient was 109.8-246.5, and there was no phytotoxic effect. In addition, mineral oil pesticides greengrass, diatomaceous earth and other pesticides or adjuvants combined with neonicotinoid pesticides can also improve the control effect on target pests.
The compound application of other pesticides mainly includes triazoles, methoxyacrylates, nitro-aminoguanidines, amitraz, quaternary keto acids, mineral oils and diatomaceous earth, etc. When screening pesticides, we should be alert to the problem of phytotoxicity and effectively identify the reactions between different types of pesticides. Compounding examples also show that more and more types of pesticides can be compounded with neonicotinoid pesticides, providing more options for pest control.
10 Conclusion and Outlook
The widespread use of neonicotinoid pesticides has led to a significant increase in the resistance of target pests, and their ecological disadvantages and health exposure risks have become current research hotspots and application difficulties. The rational compounding of different pesticides or the development of insecticidal synergistic agents is an important measure to delay drug resistance, reduce application and increase efficiency, and also a major strategy for the sustainable application of such pesticides in actual agricultural production. This paper reviews the application progress of typical neonicotinoid pesticides in combination with other types of pesticides, and clarifies the advantages of pesticide compounding: ① delaying drug resistance; ② improving control effect; ③ expanding control spectrum; ④ enhancing duration of effect; ⑤ improving quick effect ⑥ Regulate crop growth; ⑦ Reduce pesticide usage; ⑧ Improve environmental risks; ⑨ Reduce economic costs; ⑩ Improve chemical pesticides. At the same time, high attention should be paid to the combined environmental exposure of the formulations, especially the safety of non-target organisms (for example, natural enemies of pests) and sensitive crops at different growth stages, as well as scientific issues such as differences in control effects caused by changes in the chemical characteristics of pesticides. The creation of traditional pesticides is time-consuming and labor-intensive, with high costs and a long research and development cycle. As an effective alternative measure, pesticide compounding, its rational, scientific and standardized application not only prolongs the application cycle of pesticides, but also promotes a virtuous cycle of pest control. The sustainable development of the ecological environment provides a strong support.
Post time: May-23-2022