CN105123736A - Prevention and treatment application of imidacloprid and spinosad compounded agent on bradysia odoriphaga larva - Google Patents

Abstract

The invention discloses the application of a mixture of imidacloprid and spinosyn to prevent and control the larvae of the tardy-eyed fungus. In imidacloprid and spinosad mixed agent of the present invention, the weight ratio of imidacloprid and spinosyn is 1:5-1:40, and the preferred weight ratio is imidacloprid and spinosad mixed agent of 1:20, to the 3rd age The insecticidal activity of the larvae of T. chinensis has a significant synergistic effect. Among them, the mixture of imidacloprid and spinosad with a weight ratio of 1:20 showed high indoor toxicity and co-toxicity coefficient to the 3rd instar Chive tardigrade larvae, which can be used to effectively control Chive tardigrade in the production of Chinese chives. Eye fungus larvae control.

Description

Application of Imidacloprid and Spinosyn Mixture in Controlling Bradyphagia larvae in Chives

technical field

The invention relates to the application of a compound composed of imidacloprid and spinosad in the prevention and control of tardy-eyed fungus larvae of chives, and belongs to the technical field of compound pesticides.

Background technique

Reasonable mixing of insecticides can not only improve the control effect of insecticides, expand the insecticidal spectrum and application range, but also reduce the dosage of insecticides and reduce the cost of control. In addition, since the resistance mechanism of pests to each agent with different action mechanisms in the mixture is difficult to exist at the same time, it is difficult to simultaneously develop resistance to a variety of insecticides with different action modes. The use is also conducive to effectively delaying the development of pest resistance.

Bradysiaodoriphaga Yanget Zhang, whose larvae are commonly known as chive maggots, belongs to the order Diptera, the family Bradysiaodoriphaga, and the genus Bradysiaodoriphaga Yanget Zhang. It is a unique underground pest in my country that causes serious harm to the production of vegetables such as leeks. The larvae of Chive tardigrades feed on the roots of leeks and bore into the pseudostems of leeks. In severe cases, they can cause the leeks to wither, fall, die, and cause serious losses to the production of leeks. Chemical control is widely used in the control of tardy-eyed fungus larvae due to its fast action and good control effect.

Because leek maggots damage the underground rhizomes of leeks with their larvae, at present, the chemical control of leek maggots is mainly carried out by using highly toxic organophosphorus pesticides such as chlorpyrifos and phoxim to irrigate the roots of leeks. This method of using highly toxic pesticides to irrigate the roots of leeks to prevent and control leek maggots has the disadvantages of large dosage in the field, excessive pesticide residues in leeks and soil, and strong toxic effects on non-target organisms such as humans.

Therefore, it is an urgent problem to be solved in the chemical control of leek maggots and the safe production of leeks to screen efficient and environmentally friendly insecticides and chemical combinations that can be used for the control of leek maggots and reduce the use and amount of highly toxic pesticides.

At present, there are few reports on the mixture of insecticides used for the prevention and treatment of chive maggots, and only 50% chlorpyrifos-cypermethrin EC and 20% phoxim-chlorpyrifos EC are used for the prevention and control of chive maggots. Studies have reported the toxicity of two mixtures of 200mg/L clothianidin and 18mg/L beta-cypermethrin, 200mg/L clothianidin and 25mg/L hexaflumuron to leek maggots. In addition, some studies have determined the indoor toxicity of imidacloprid mixed with three organophosphorus insecticides to the larvae of the larvae of the chive larvae. The synergistic coefficient reaches 338.5.

At present, some studies have disclosed the application of a mixture of imidacloprid and spinosyn in aphids and thrips (Chinese invention patent publication numbers: CN102578132A and CN101305723A). Aphids and planthoppers are Homoptera insects with piercing-sucking mouthparts, thrips are Thysanoptera insects, and tardiphagus leeks are Diptera insects. Chemical control of Diptera insects is different from the control of piercing-sucking mouthparts pests of Homoptera, and insecticides used to control Thysanoptera pests, such as spinosad can well control Lepidoptera and Diptera insects , but ineffective against aphids and thrips.

At present, there is no research report on the use of imidacloprid and spinosyn to form a mixture to control diptera underground pests-Bladiopteris larvae.

Contents of the invention

The purpose of the present invention is to provide the application of imidacloprid and spinosad mixture in the prevention and control of tardigrade larvae of chives.

As a neonicotinoid insecticide, imidacloprid is an agonist of nicotinic acetylcholine receptors (nAChRs) in the insect nervous system. The mode of action of imidacloprid on pests is mainly gastric toxicity, and it is an effective agent for pest control. At the same time, imidacloprid has low toxicity to humans and other mammals. Therefore, imidacloprid insecticide has the characteristics of high efficiency and low toxicity. Imidacloprid has a good control effect on Homoptera insects aphids and Thysanoptera insects such as thrips.

Spinosad is a biopesticide of macrolides. It acts on the nicotinic acetylcholine receptor (nAChR) of insects, causing it to be continuously activated and causing a prolonged release of acetylcholine (ACh). Spinosyn also acts on At the γ-aminobutyric acid (GAGB) receptor, the function of the GABA-gated chloride channel is changed, which further promotes the improvement of its insecticidal activity. The binding site of spinosyn on the nicotinic acetylcholine receptor is different from that of nicotine and imidacloprid. Spinosad has rapid contact and ingestion toxicity to insects. Spinosyn can effectively control Lepidoptera, Diptera and Thysanoptera pests, has no major impact on beneficial organisms, has good biological and environmental compatibility, and is suitable for use on vegetables, fruit trees, gardening, and crops. However, the effect on piercing-sucking mouthparts such as aphids is poor.

Therefore, in order to screen and develop efficient and environmentally friendly insecticide mixtures that can be used for the control of tardigrade larvae in chives, the effect of a mixture of imidacloprid and spinosad with good environmental compatibility on chive maggots was studied. On the basis of indoor toxicity, the invention discloses a mixture composed of imidacloprid and spinosyn, which can be used for the prevention and control of tardy-eyed fungus larvae.

In the present invention, imidacloprid and spinosad are made into a compounding agent according to a weight ratio of 1:5-1:40, preferably a compounding agent with a weight ratio of 1:20, to kill insects of the 3rd instar tardigrade leek larvae The activity is not a simple addition of the insecticidal activity of the two components, but a significant synergistic effect. Among them, the LC ₅₀ of imidacloprid and spinosad mixed with 1:20 weight ratio to the larvae of the 3rd instar Chive tardigrade was 5.389mg/L, showing very high insecticidal activity to Chive maggots, and the weight The co-toxicity coefficient of the mixture of imidacloprid and spinosad with a ratio of 1:20 reached 1272, and the synergistic effect was extremely significant, exceeding the reported mixture of imidacloprid and phoxim at a concentration ratio of 1:5. Toxicity and synergistic coefficient of chive maggots (Wang Zhichao, Wang Siyi, Shi Xueyan, Song Dunlun, Gao Xiwu, Indoor toxicity determination of imidacloprid and three organophosphorus insecticides on the larvae of Chive maggots, Chinese Journal of Plant Protection, 2014 , 41(4):511-512).

For preparing the compounding agent that imidacloprid and spinosad are formed, and obtaining its indoor toxicity and the co-toxicity coefficient to the larvae of the 3rd instar tardigrade leek, the technical solution of the present invention is solved like this:

First, imidacloprid and spinosad are made into a compounding agent according to the weight ratio of 1:5, 1:10, 1:20, 1:40 (1:5—1:40), preferably the weight ratio is 1:20. Dispensing.

Then, the indoor bioassay of the mixture of imidacloprid and spinosyn in different weight ratios on the larvae of the third instar B. After adopting the method that leeks and 3rd instar tardigrade larvae were treated with insecticides, and then the 3rd age larvae were fed, the mixture of imidacloprid and spinosad in different weight ratios was carried out for 3 Indoor bioassays of instar tardyphagia larvae.

According to the indoor bioassay results, the indoor toxicity of imidacloprid and spinosyn mixture to the 3rd instar tardymusia larvae and the co-toxicity coefficient of the mixture were finally obtained by calculation.

The results show that imidacloprid and spinosad are mixed according to the weight ratio of 1:5-1:40, preferably the mixture of 1:20 weight ratio, the insecticidal activity to the larvae of the 3rd instar tardy-eyed fungus is different. Instead of a simple addition of the insecticidal activity of the two components, there was a significant synergistic effect (Table 1). Among them, the LC ₅₀ of imidacloprid and spinosyn mixture with a weight ratio of 1:20 to the larvae of the 3rd instar Chive larvae was 5.389 mg/L, showing very high insecticidal activity to the chive maggots, and the weight ratio The co-toxicity coefficient of imidacloprid and spinosad mixture of 1:20 reached 1272, surpassing the toxicity and enhancement of the mixture of imidacloprid and phoxim with a concentration ratio of 1:5 to leek maggots reported. Effect coefficient (Wang Zhichao, Wang Siyi, Shi Xueyan, Song Dunlun, Gao Xiwu, Determination of indoor toxicity of imidacloprid mixed with three organophosphorus insecticides to tardyphagia larvae, Chinese Journal of Plant Protection, 2014,41(4):511 -512). The mixture of imidacloprid and spinosad with a weight ratio of 1:20 has a good control effect on the larvae of the 3rd instar Chive tardigrade, and can be used to effectively control Chive maggots in the production of Chives.

Since imidacloprid and spinosad are both selective and environmentally friendly insecticides, in the production of leeks, a mixture of imidacloprid and spinosad can be used in a weight ratio of 1:5-1:40, preferably the weight ratio The 1:20 mixture of imidacloprid and spinosad can be used to prevent and control the larvae of the larvae of the chive larvae, which can reduce the amount of pesticides used and solve the problem of not using highly toxic organophosphorus pesticides to control chive maggots. In order to carry out the pollution-free production of chives, an insecticide mixture with high efficiency and good environmental compatibility is provided for the application of the control of the larvae of the chives tardy-eyed fungus.

Detailed ways

The present invention will be described below through specific examples, but the present invention is not limited thereto.

The experimental methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials, unless otherwise specified, can be obtained from commercial sources.

Embodiment 1: Indoor toxicity determination of insecticides to tardy-eyed fungus larvae

Chive tardigrade is an indoor population that feeds on the pseudostem of leek in a petri dish and has been raised continuously for one year in the Insect Toxicology Laboratory of China Agricultural University. Feeding conditions: Pour 2.5% agar into a petri dish to keep it moist, and spread a circular filter paper, gently pick the larvae of Chive tardigrades on the filter paper with a fine brush, and feed them with 1-2 cm chive pseudostem segments. The petri dishes were raised at a temperature of 23±1° C. and a relative humidity of RH60%, without contact with any insecticides during the raising.

Since the 3rd instar T. larvae larvae are larger in size, eat more food, and cause serious harm, the indoor toxicity determination of insecticides on the larvae of T. Insects to be tested.

Insecticides tested: 95.3% imidacloprid technical, Jiangsu Changlong Chemical Co., Ltd.; 99.1% spinosad technical, Dow AgroSciences.

Preparation of mixture of imidacloprid and spinosyn with a weight ratio of 1:5—1:40 and its indoor toxicity test to 3rd instar tardyphagia larvae (Imidacloprid and spinosyn Mixture as an example):

First, imidacloprid and spinosad are formed into a mixture with a weight ratio of 1:20, and then the mixture with a weight ratio of 1:20 is diluted to 5 different concentration gradients (33.6mg/ L, 16.8mg/L, 8.4mg/L, 4.2mg/L, 2.1mg/L), used to measure the indoor toxicity of the mixture of 1:20 by weight to the 3rd instar Brachycephalus larvae.

The indoor toxicity determination of imidacloprid and spinosad mixture with a weight ratio of 1:20 on the 3rd instar tardyphagia larvae of Chinese chives was carried out after the insecticide treatment was carried out on leeks and 3rd instar tardyphalyphagia larvae respectively. The method of feeding the larvae of the 3rd instar Chive tardigrade was carried out, and the determination results of this method reflected the joint poisoning effect of stomach poisoning and contact killing at the same time. Specifically:

Pour molten 2.5% agar into a six-hole bioassay plate to a thickness of 2 mm. After cooling and solidifying, spread a circular filter paper slightly smaller than the diameter of the bioassay hole on the agar. Cut the washed and dried chive pseudostems into 1.5cm-long sections, soak them in insecticide solutions ranging from low to high concentrations for 15 seconds, take them out and dry them, and place them in the round tubes in the biometric holes. on filter paper.

Use a wet fine brush to pick the larvae of the 3rd-instar Bradyphagia chives into the insect net, completely immerse the net in the liquid medicine for 15 seconds, take it out, put it on absorbent paper to remove excess water, and put the larvae in the net with The brush is gently picked into the six-hole bioassay plate with the pseudostem of chives dipped in the medicinal solution. Paste the bioassay orifice of the bioassay plate with rice paper. The bioassay plate was cultured in a dark place at a temperature of 23±1°C and a relative humidity of 60%. Each concentration of pesticide treatment was repeated three times, and each repetition was carried out with 20 test insects. The 3rd-instar tardyphagia larvae treated with 0.1% TritonX-100 in distilled water were used as a control, and the mortality rate was less than 10% for effective determination.

After 24 hours, observe and record the number of dead larvae of the 3rd-instar tardyphagia larvae, lightly touch the larvae with a brush, and if the larvae do not move, they are regarded as dead, and the mortality rate is calculated.

In order to calculate the co-toxicity coefficient of the joint virulence effect of the mixed agent on the larvae of the 3rd instar T. larvae, the same method was used to measure the effects of a single agent of imidacloprid and a single agent of spinosad on the larvae of the 3rd instar T. larvae. Indoor toxicity.

Example 2: Calculation of the indoor toxicity and co-toxicity coefficient of imidacloprid and spinosad mixture to 3rd instar tardyphagia larvae.

The indoor toxicity of the mixture of imidacloprid and spinosyn to the larvae of the 3rd-instar Bradyphagia chives was measured by LC ₅₀ , 95% confidence interval (95% CL). Aiming at the mortality rate of 3rd-instar tardyphagia larvae treated with 5 different concentrations of the mixture, the concentration of the mixture and the mortality rate of the maggot were brought into POLO1.0 software to calculate LC ₅₀ and 95% confidence interval et al., obtained the indoor toxicity of the mixture to the larvae of the 3rd-instar Bradyophthora chives. The same method was used to calculate the indoor toxicity of imidacloprid single dose and spinosyn single dose to 3rd instar tardyphagia larvae.

In the mixture, the joint toxicity of the two insecticides on the larvae of the 3rd-instar T. chileensis was measured by the co-toxicity coefficient (CTC) value. Using Excel2003 to calculate the CTC of the two insecticides in the mixture against the larvae of the 3rd instar Bradyphagia chives. The calculation of CTC was carried out with reference to Sun Yunpei's method (SunYP, Johnson ER. Analysis of joint action of insecticides against houseflies [J]. Econ. Entomol., 1960, 10(53): 887-891). The calculation formula is:

Toxicity index (TI) = (LC ₅₀ of standard drug / LC ₅₀ of test drug) × 100

Mixture Actual Toxicity Index (ATI) = (LC ₅₀ of standard drug alone / LC ₅₀ of mixture) × 100

Mixture theoretical toxicity index (TTI) = ATI (A) × A percentage in the mixture + ATI (B) × B percentage in the mixture

Co-toxicity coefficient (CTC) = [mixture actual toxicity index (ATI) / mixture theoretical toxicity index (TTI)] × 100

If CTC<80, it indicates that the mixed use of the two agents is an antagonistic effect; if 80<CTC<120, it is an additive effect; if CTC>120, it is a synergistic effect.

See Table 1 for the toxicity and co-toxicity coefficient results of imidacloprid and spinosad mixtures with a weight ratio of 1:5-1:40 on 3rd instar tardigrade larvae.

Table 1: Toxicity and co-toxicity coefficient of the mixture of imidacloprid and spinosad against larvae of the third instar B.

Imidacloprid and spinosyn form a compound with a weight ratio of 1:5-1:40, preferably the imidacloprid and spinosyn compound with a weight ratio of 1:20, the insecticidal activity of the 3rd instar tardy-eyed fungus larvae is not The simple addition of the insecticidal activity of the two components has a significant synergistic effect. Among them, the LC ₅₀ of imidacloprid and spinosyn mixture with a weight ratio of 1:20 to the larvae of the 3rd instar Chive larvae was 5.389 mg/L, showing very high insecticidal activity to the chive maggots, and the weight ratio The co-toxicity coefficient of the mixture of imidacloprid and spinosad at 1:20 reached 1272. The mixture of imidacloprid and spinosyn with a weight ratio of 1:5-1:40, preferably the mixture of imidacloprid and spinosyn with a weight ratio of 1:20, is indoor toxic to the larvae of the 3rd instar tardigrade leek. Both the potency and the co-toxicity coefficient are high, and it can be used to effectively control leek maggots in the production of leeks.

The mixture of imidacloprid and spinosyn of the invention has the characteristics of good environmental compatibility and low toxicity to mammals. The mixed agent composed of imidacloprid and spinosad obtained in the present invention can replace the highly toxic pesticides for the prevention and treatment of leek maggots, effectively prevent and control the leek maggots in the growth of leeks, and solve the chemical control of leek maggots and reduce the use of highly toxic pesticides in the safe production of leeks In order to solve the problem of pollution-free production of leeks, an insecticide mixture with high efficiency and good environmental compatibility is provided.

Claims (4)

1. the purposes of the mixed agent that a kind of imidacloprid and spinosad are formed in the prevention and control of tardy-eyed fungus larvae. 2. The use according to claim 1, wherein the compounding agent composed of imidacloprid and spinosyn is a compounding agent with a weight ratio of 1:5-1:40. 3. purposes according to claim 2, the compounding agent that described imidacloprid and spinosyn are formed is the compounding agent that weight ratio is 1:20. 4. The use according to claim 1, wherein the larvae of T. chives are 3rd instar T. chives larvae.