Compound agent for preventing and treating termite based on serratia marcescens

Abstract

The application provides a compound agent for preventing and treating termites based on Serratia marcescens, which comprises 7.75x10 8 ~2.63x10 12 CFU / mL of Serratia marcescens, and a pathogenic fungus or a biological pesticide or an insect growth regulator or a chemical agent; the pathogenic fungus is Beauvaria bassiana or Metarhizium anisopliae; the biological pesticide is ivermectin; the insect growth regulator is lufenuron or buprofezin or diflubenzuron; and the chemical agent is emamectin benzoate or indoxacarb. The compound agent has obvious synergistic effect on preventing and treating termites, reduces the use amount of single agent, is lower in cost, more efficient, stable and green.

Description

Technical Field

[0001] This invention belongs to the field of termite control, specifically relating to a compound agent for termite control based on Serratia marcescens. Background Technology

[0002] Termites are well-known social insects that typically feed on cellulose, causing significant damage to buildings, crops, standing trees and forests, reservoirs and dams, resulting in substantial losses for humankind (Su and Scheffrahn., 2000; Wang et al., 2018; Chiu et al., 2022). Therefore, finding safe and effective pesticides is a crucial direction for termite control. Gram-negative bacteria *Serratia marcesens* are widely found in both laboratory-reared and field-collected insects and are pathogenic to many insects, including those in the orders Orthoptera, Homoptera, and Lepidoptera (Nehme et al., 2007; Niu et al., 2015; Aggarwal et al., 2017). Studies have shown that *Serratia marcescens* (SM1) has promising applications in the biological control of pests (Bidari et al., 2017; Atanakul et al., 2020; Zhao et al., 2020). Our previous research also demonstrated that *Serratia marcescens* has good control effects against black-winged subterranean termites (Fu et al., 2021; Wang et al., 2024). Therefore, the application of *Serratia marcescens* in pest control has great potential.

[0003] In addition to being used directly as biological agents to control pests, insect pathogens can also be used as biosynthetic agents for chemical pesticides or insect growth regulators. Insect pathogens, chemical pesticides, insect growth regulators, biopesticides, and pathogenic fungi each have their own advantages, making their combined application a good method for solving many pest problems (Paula et al., 2011). Summary of the Invention

[0004] The purpose of this invention is to control termites by combining Serratia marcescens with different types of insecticides, thereby obtaining a more green and efficient compound agent for termite control.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a compound agent for controlling termites based on Serratia marcescens, wherein the compound agent composition is Serratia marcescens and insect growth regulators or pathogenic fungi or biological pesticides or chemical agents;

[0007] The insect growth regulator is lufenuron, thiamethoxam, or hydrazine;

[0008] The pathogenic fungus is either Beauveria bassiana or Metarhizium anisopliae.

[0009] The biopesticide in question is ivermectin;

[0010] The chemical agent is ivermectin, abamectin, or indoxacarb;

[0011] The bacterial count of *Serratia marcescens* was 7.75 × 10⁻⁶. 8 ~2.63×10 12 CFU / mL;

[0012] The pathogenic fungus is 2×10 8 Conidia / mL;

[0013] The ivermectin concentration is 0.01–0.05 mg / mL;

[0014] The concentration of the insect growth regulator is 1–5.11 mg / mL;

[0015] The concentration of the chemical reagent is 0.01–0.02 mg / mL.

[0016] Furthermore, when the compound pharmaceutical composition is a combination of *Serratia marcescens* and thiamethoxam, the *Serratia marcescens* concentration is 7.75 × 10⁻⁶. 8 ~8.75×10 10 CFU / mL, thiamethoxam concentration is 1 mg / mL to 10 mg / mL -2 The concentration ratio is 1 to 3.05 mg / mL, and the volume ratio of the compound is 9:1 to 1:2.

[0017] When the compound pharmaceutical composition consists of *Serratia marcescens* and a pathogenic fungus, the *Serratia marcescens* content is 2.63 × 10⁻⁶. 12 CFU / mL, pathogenic fungus 2×10 8 Conidia / mL, with a volume ratio of 2:1 to 1:2.

[0018] When the compound pharmaceutical composition consists of *Serratia marcescens* and hydrazine, the *Serratia marcescens* content is 7.75 × 10⁻⁶. 8 CFU / mL, hydrazine 1 mg / mL, and the volume ratio of the compound is 5:1-1:9.

[0019] When the compound pharmaceutical composition consists of *Serratia marcescens* and lufenuron, the *Serratia marcescens* content is 8.75 × 10⁻⁶. 10 CFU / mL, lufenuron concentration 10 -2mol / L (5.11 mg / mL), with a volume ratio of 2:1 to 1:2.

[0020] When the compound pharmaceutical composition is *Serratia marcescens* and emamectin benzoate or indoxacarb, the *Serratia marcescens* content is 7.75 × 10⁻⁶. 8 The concentration of CFU / mL is 0.02 mg / mL for abamectin and 0.01 mg / mL for indoxacarb. The volume ratio of Serratia marcescens to abamectin or indoxacarb is 5:1 to 1:9.

[0021] When the compound drug is 7.75×10 8 When Serratia marcescens CFU / mL is combined with ivermectin at a volume ratio of 5:1 to 1:9, the ratio is 5:1 to 1:9.

[0022] When the compound drug is 8.75×10 10 CFU / mL Serratia marcescens and 5.71×10 -5 When 0.05 mg / mL ivermectin is combined, the volume ratio is 2:1 to 1:2.

[0023] Furthermore, the volume ratio of the Serratia marcescens to thiamethoxam is 1:1.

[0024] Furthermore, the termites are *Reticulitermes nigra* or *Reticulitermes nigra*.

[0025] The beneficial effects of this invention are:

[0026] (1) By combining Serratia marcescens with other low-toxicity and low-residue agents, the insecticidal time can be shortened, the stability can be improved, the control effect can be enhanced, and the amount of insecticide used can be reduced, which is green, safe and pollution-free to the environment.

[0027] (2) The combined application of insect pathogenic bacteria and pathogenic fungi or biopesticides or insect growth regulators or chemical insecticides can increase toxicity to pests while reducing the dosage of each.

[0028] (3) The novel biological agent with enhanced toxicity of black-winged subterranean termite or black-breasted subterranean termite provided by the present invention will provide new evidence for the prevention and control of harmful insects by compound preparations of insect pathogens and novel agents, and will also provide a new theoretical basis for the development of compound agents for the prevention and control of termites. Attached Figure Description

[0029] Figure 1 Corrected mortality rate of black-winged subterranean termites treated with a combination of SM1 and hydrazine-suppressing agent.

[0030] Figure 2 Corrected mortality rate of black-winged subterranean termites treated with a combination of SM1 and thiamethoxam.

[0031] Figure 3 Corrected mortality rate of black-winged subterranean termites treated with a combination of SM1 and abamectin.

[0032] Figure 4 Corrected mortality rate of black-winged subterranean termites treated with a combination of SM1 and indoxacarb.

[0033] Figure 5 Corrected mortality rate of black-winged subterranean termites treated with a combination of SM1 and ivermectin. Detailed Implementation

[0034] I. Materials and Methods

[0035] The tested insects, *Reticulitermes nigra* and *Odontotermes nigra*, were collected from Nanjing, Jiangsu Province. The collected *Odontotermes nigra* were placed in a device separating the fungal garden area from the feeding area and reared under conditions of room temperature (25±1)℃, relative humidity 80%±5% RH, and 24h darkness.

[0036] The collected black-breasted subterranean termites were reared in a 20cm×8cm×5cm plastic box under the following environmental conditions: darkness, temperature maintained at 25±1℃, and relative humidity maintained at 90±5%. The termites used in the experiment were uniform and robust worker termites.

[0037] II. Test bacteria and reagent preparation

[0038] Serratia marcescens Bizio SM1 strain: isolated from infected and dead reddened termites, purified, and stored in our laboratory at -80°C.

[0039] The SM1 strain stock solution, stored at -80℃, was thawed. 1 μL was added to 50 mL of autoclaved (121℃ for 25 min) fermentation medium (10 g / L peptone + 30 g / L soybean oil + 2 g / L NaCl + 2 g / L K₂HPO₄, pH 7.5), and cultured by shaking at 30℃ and 200 rpm for 36 h. The bacterial culture was then prepared and its OD was measured using a UV spectrophotometer. 600 Stop shaking when the concentration of SM1 bacterial culture reaches 0.6. Dilute the SM1 bacterial culture to 7.75 × 10⁶ before use. 8 CFU / mL, 8.75×10 8 and 2.63×10 12 CFU / mL.

[0040] Beauveria bassiana (Bb) was cultured on potato dextrose agar (PDA) medium in an incubator at (25±1)℃ and (75±5)% RH for 15 days. When colonies began sporulation, the medium was tilted, and mycelia and spores were gently scraped away with an inoculation needle. 0.05% Tween-80 sterile water was added, and the mixture was shaken and filtered to prepare a stock solution. The number of spores per milliliter of the stock solution was counted using a hemocytometer. The stock solution was then diluted to a concentration of 2×10⁻⁶. 8 CFU / mL spore suspension.

[0041] Metarhizium anisopliae (Ma) was cultured on LB medium and diluted to a concentration of 2 × 10⁻⁶ using the same procedure. 8 A spore suspension of CFU / mL.

[0042] 91.4% methamidophos technical (RH-5849) was purchased from Jiangsu Yunnong Chemical Co., Ltd.; 98% thiamethoxam technical (BUP) was purchased from Shandong Huayang Pesticide Chemical Group Co., Ltd.; 74.2% abamectin technical (EMB) was purchased from Nanjing Hongtaiyang Co., Ltd.; 93% indoxacarb technical (IND) was purchased from Jiangsu Jiannong Plant Protection Co., Ltd.; 50 mg / 5 g ivermectin (IVE) was purchased from Zhongnong Huawai (Hubei) Biopharmaceutical Co., Ltd.; 97.3% lufenuron was purchased from Shandong Lvba Chemical Co., Ltd.; and 97% thiamethoxam was purchased from Jiangsu Huifeng Shengmu Agriculture Co., Ltd. Each technical was dissolved in acetone to obtain concentrations of 0.01 mg / mL and 5.71 × 10⁻⁶ mg / mL. -5 mol / L ivermectin, 1 mg / mL and 1×10 -2 mol / L thiamethoxam, 1×10 -2 mol / L lufenuron, 1 mg / mL cypermethrin, 0.02 mg / mL abamectin and 0.01 mg / mL indoxacarb.

[0043] III. Drug formulation and bioassay methods

[0044] 1. Synergistic toxicity of compound agents based on Serratia marcescens against black-winged subterranean termites

[0045] Take 540 μL of 7.75 × 10⁻⁶ solution respectively. 8 CFU / mL SM1 bacterial culture with 60μL 1mg / mL hydrazine inhibitor and 500μL 7.75×10 8 CFU / mL SM1 bacterial culture with 100μL 1mg / mL hydrazine inhibitor and 300μL 7.75×10 8 CFU / mL SM1 bacterial culture mixed with 300μL 1mg / mL hydrazine inhibitor and 100μL 7.75×10 8 CFU / mL SM1 bacterial culture mixed with 500μL 1mg / mL hydrazine inhibitor and 60μL 7.75×10 8CFU / mL SM1 bacterial suspension was thoroughly mixed with 540 μL of 1 mg / mL cypermethrin to prepare compound formulations with volume ratios of 9:1, 5:1, 1:1, 1:5, and 1:9, respectively. Compound formulations of SM1 with thiamethoxam, indoxacarb, ivermectin, and emamectin benzoate were also prepared using this method.

[0046] Place a 7cm diameter qualitative filter paper flat in a suitable-sized petri dish. Take 600μL of the compounded reagent and evenly drip it onto the filter paper from the outer edge inwards, spreading it evenly so that the filter paper adheres to the bottom of the dish without gaps. Allow it to dry slightly before covering. Place 30 healthy, similarly aged black-winged subterranean termite worker ants outside the nest in each dish. Conduct the experiment under dark conditions at (25±1)℃ and (80±5)%RH. Observe every 12 hours. Individuals that cannot straighten their bodies and do not move after being lightly touched with a brush are considered dead. Remove the dead worker ants and record the number of deaths. Continuously observe, adding water to the filter paper during observation to keep it moist, using clean water as the water source, until the end of the experiment. The compounded reagent is applied according to the five compound ratios mentioned above, with four replicates for each treatment. Acetone is used as a control (preliminary experimental results show no difference between using fermentation broth as a control and using acetone as a control).

[0047] 2. Synergistic toxicity of novel compound biological agents based on Serratia marcescens against Reticulitermes nigra.

[0048] Take 400 μL of 8.75 × 10⁻⁶ mol / L of each product. 10 CFU / mL SM1 bacterial culture with 200μL 1×10 -2 mol / L lufenuron, 200μL 8.75×10 10 CFU / mL SM1 bacterial culture with 200μL 1×10 -2 mol / L lufenuron, 200μL 8.75×10 10 CFU / mL SM1 bacterial culture with 400μL 1×10 -2 1 mol / L lufenuron was thoroughly mixed to prepare compound formulations with volume ratios of 2:1, 1:1, and 1:2. Compound formulations of SM1 with thiamethoxam, ivermectin, Beauveria bassiana, and Metarhizium anisopliae were also prepared using this method.

[0049] The immersion method was used for bioassay. Filter paper was cut to the size of a petri dish, laid flat in the dish, and moistened with water. Healthy, vigorous, and similarly sized worker termites of the subterranean termite were selected for the experiment. The termites were immersed in the liquid droplet for 10 seconds, and then immediately picked up with a brush and returned to the dish. The petri dish was placed in the dark, and the mortality rate of the worker termites was recorded at regular intervals. Three replicates were set up for each single agent and each ratio of the compound reagent, and three replicates were also set up for the control.

[0050] IV. Statistical Analysis

[0051] The mortality rate of termites was corrected using the Abbott formula (Abbott., 1925): Corrected mortality rate = (TC) / (1-C) × 100; T represents the mortality rate of the treatment group and C represents the mortality rate of the control group.

[0052] All experimental data were processed using the DPS data processing system (Tang and Zhang, 2013). The software's professional statistical—biostatistics and pharmacokinetics—quality response probability value analysis function was used to analyze the median lethal time (LT) of the biopesticide SM1 in combination with other agents. 50 Analysis of variance (ANOVA) was performed on the collected data using InStat software (GraphPad, San Diego, CA, USA). One-way ANOVA was used to assess the significance among multiple samples, followed by Tukey's test for comparison, with a significance level set at P < 0.05. The co-toxicity coefficient (CTC) method (Sun and Johnson, 1960) was used to analyze the co-toxicity of SM1 with various pesticide mixtures on termites.

[0053] The TI of the standard reagent is 100.

[0054] Toxicity Index (TI) = (LT of standard insecticide) 50 / LT of the test single agent 50 )×100

[0055] Actual Toxicity Index (ATI) = (LT of standard insecticide) 50 / Lt of Mixture 50 )×100

[0056] Theoretical toxicity index (TTI) of a mixture = (Toxicity index of single agent A × Percentage content of agent A in the mixture + Toxicity index of single agent B × Percentage content of agent B in the mixture) × 100.

[0057] Co-toxicity coefficient (CTC) = Actual toxicity index (ATI) / Theoretical toxicity index (TTI) of the mixture × 100

[0058] The synergistic effect is determined by the magnitude of the CTC value: CTC < 80 indicates an antagonistic effect; 80 ≤ CTC ≤ 120 indicates an additive effect; and CTC > 120 indicates a synergistic effect (Sun and Johnson, 1960).

[0059] V. Results Analysis

[0060] 1. Toxicity determination of Serratia marcescens SM1 combined with hydrazine (RH-5849) on black-winged subterranean termites

[0061] from Figure 1 It can be seen that the value is 7.75 × 10⁻⁶ over 24 hours. 8 The corrected mortality rate in the treatment group with a CFU / mL SM1 to 1 mg / mL hydrazine volume ratio of 1:5 was significantly higher than that in the single-dose treatment group; the mortality rate was 7.75 × 10⁻⁶ between 48 h and 96 h. 8 The corrected mortality rate of black-winged subterranean termites treated with a mixture of CFU / mL SM1 and 1 mg / mL hydrazine at volume ratios of 1:1, 1:5, and 1:9 showed a significant difference compared to the single-agent treatment groups; and the mortality rate was 7.75 × 10⁻⁶. 8 The corrected mortality rate in the group treated with a CFU / mL SM1 to 1 mg / mL hydrazine volume ratio of 9:1 was lower than that in the single-dose treatment group at all time points.

[0062] As shown in Table 1, 7.75 × 10 8 The LT50 of CFU / mL SM1 against black-winged subterranean termites was 74.26 h; the LT50 of 1 mg / mL hydrazine against black-winged subterranean termites was... 50 It is 54.98 hours. 7.75 × 10⁻⁶ 8 A mixture of CFU / mL SM1 and 1 mg / mL hydrazine at a volume ratio of 9:1 showed a low LT (total toxicity) of [a specific toxicity level] against black-winged subterranean termites. 50 It was 63.24h; 7.75×10 8 A mixture of CFU / mL SM1 and 1 mg / mL hydrazine at a volume ratio of 5:1 showed a low LT (total toxicity) of [a specific toxicity level] against black-winged subterranean termites. 50 It was 45.13 hours; 7.75 × 10⁻⁶ hours. 8 A 1:1 volume ratio of CFU / mL SM1 and 1 mg / mL hydrazine was used to inhibit the LT (total phosphatidylcholine) of black-winged termites. 50 It was 31.37 h; 7.75 × 10 8 A mixture of CFU / mL SM1 and 1 mg / mL hydrazine at a volume ratio of 1:5 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 24.52h; 7.75×10 8 A mixture of CFU / mL SM1 and 1 mg / mL hydrazine at a volume ratio of 1:9 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It is 38.01h.

[0063] Table 1. Toxicity determination of SM1 and hydrazine combination in black-winged subterranean termites.

[0064]

[0065] Table 2. Co-toxicity coefficients of SM1 and hydrazine in combination with black-winged subterranean termites.

[0066]

[0067] TI, ATI, TTI, and CTC represent the toxicity index, actual toxicity index, theoretical toxicity index, and co-toxicity coefficient, respectively.

[0068] Table 2 shows that, using SM1 as the standard reagent, the toxicity index of hydrazine is 135.07. (When 7.75 × 10⁻⁶...) 8 When CFU / mL SM1 and 1 mg / mL hydrazine are mixed at a volume ratio of 9:1, the actual toxicity index of the mixture is 117.43, the theoretical toxicity index is 103.51, and the co-toxicity coefficient is 113.45, which is less than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL hydrazine are combined at a volume ratio of 9:1, they exhibit additive toxicity against black-winged subterranean termites. (The text abruptly ends here, seemingly mid-sentence.) 8 When CFU / mL SM1 and 1 mg / mL hydrazine are mixed at a volume ratio of 5:1, the actual toxicity index of the mixture is 164.55, the theoretical toxicity index is 105.84, and the co-toxicity coefficient is 155.46, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL hydrazine were combined at a volume ratio of 5:1, the toxicity of the mixture against black-winged subterranean termites was enhanced. When SM1 and 1 mg / mL hydrazine were combined at a volume ratio of 1:1, the actual toxicity index of the mixture was 236.72, the theoretical toxicity index was 117.53, and the co-toxicity coefficient was 201.41, which is greater than 120. Therefore, 7.75 × 10⁻⁶ 8 When CFU / mL SM1 and 1 mg / mL hydrazine are combined at a 1:1 volume ratio, they exhibit synergistic toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 1 mg / mL hydrazine are mixed at a volume ratio of 1:5, the actual toxicity index of the mixture is 302.85, the theoretical toxicity index is 129.22, and the co-toxicity coefficient is 234.37, which is much greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL hydrazine are combined at a volume ratio of 1:5, the toxicity against black-winged subterranean termites is enhanced. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 8 When CFU / mL SM1 and 1 mg / mL hydrazine are mixed at a volume ratio of 1:9, the actual toxicity index of the mixture is 195.37, the theoretical toxicity index is 131.56, and the co-toxicity coefficient is 148.50, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL hydrazine are combined at a volume ratio of 1:9, they exhibit synergistic toxicity against black-winged subterranean termites.

[0069] 2. Toxicity determination of Serratia marcescens SM1 combined with thiamethoxam (BUP) to black-winged subterranean termites

[0070] from Figure 2 It can be seen that after 7.75 × 10 8 After 24 hours of treatment with CFU / mL SM1 and 1 mg / mL thiamethoxam single agents and mixtures, the phosphatidylcholine content of black-winged subterranean termites was 7.75 × 10⁻⁶. 8 The corrected mortality rate of the group treated with a 1:1 volume ratio of CFU / mL SM1 to 1 mg / mL thiamethoxam was significantly different from that of other groups; the mortality rate was 7.75 × 10⁻⁶ between 48 h and 96 h. 8 There were differences in the corrected mortality rates between the combined drug treatment groups with CFU / mL SM1 and 1 mg / mL thiamethoxam volume ratios of 9:1, 5:1, and 1:1 and the single-dose treatment groups. Furthermore, the corrected mortality rates were lower in the treatment groups with ratios of 1:5 and 1:9 throughout the experiment.

[0071] Table 3. Toxicity determination of SM1 and thiamethoxam combination in black-winged subterranean termites.

[0072]

[0073] Table 4. Co-toxicity coefficients of SM1 and thiamethoxam in black-winged subterranean termites.

[0074]

[0075] As shown in Table 3, 7.75 × 10 8 CFU / mL SM1 against the LT of black-winged subterranean termite 50 The LT of 1 mg / mL thiamethoxam against black-winged subterranean termites was 74.26 h; 50 It is 92.50h. 7.75×10 8 A mixture of CFU / mL SM1 and 1 mg / mL thiamethoxam at a volume ratio of 9:1 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 56.12h; 7.75×10 8 A mixture of CFU / mL SM1 and 1 mg / mL thiamethoxam at a volume ratio of 5:1 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 48.12h; 7.75×10 8 A 1:1 volume ratio of CFU / mL SM1 and 1 mg / mL thiamethoxam was used to treat the LT (thiamethoxam-induced leukemia) of black-winged termites. 50 It was 45.42 hours; 7.75 × 10⁻⁶ hours. 8 A mixture of CFU / mL SM1 and 1 mg / mL thiamethoxam at a volume ratio of 1:5 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 111.97 h; 7.75 × 10 8 A mixture of CFU / mL SM1 and 1 mg / mL thiamethoxam at a volume ratio of 1:9 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It is 90.26h.

[0076] Table 4 shows that, using SM1 as the standard reagent, the toxicity index of thiamethoxam is 80.28. (The last part, "7.75 × 10," appears to be an unrelated fragment and is omitted from the translation.) 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are mixed at a volume ratio of 9:1, the actual toxicity index of the mixture is 132.34, the theoretical toxicity index is 98.03, and the co-toxicity coefficient is 135.00, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam were combined at a volume ratio of 9:1, the toxicity against black-winged subterranean termites was enhanced. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are mixed at a volume ratio of 5:1, the actual toxicity index of the mixture is 154.32, the theoretical toxicity index is 96.71, and the co-toxicity coefficient is 159.57, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are combined at a volume ratio of 5:1, the toxicity against black-winged subterranean termites is enhanced. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are mixed in a 1:1 volume ratio, the actual toxicity index of the mixture is 163.50, the theoretical toxicity index is 90.14, and the co-toxicity coefficient is 181.38, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are combined at a 1:1 volume ratio, the toxicity against black-winged subterranean termites is enhanced. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are mixed at a volume ratio of 1:5, the actual toxicity index of the mixture is 66.32, the theoretical toxicity index is 83.57, and the co-toxicity coefficient is 79.36, which is less than 80. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam were combined at a volume ratio of 1:5, they exhibited antagonistic toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are mixed at a volume ratio of 1:9, the actual toxicity index of the mixture is 82.27, the theoretical toxicity index is 82.25, and the co-toxicity coefficient is 100.02, which is less than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 1 mg / mL thiamethoxam are combined in a volume ratio of 1:9, they exhibit additive toxicity against black-winged subterranean termites.

[0077] 3. Virulence determination of Serratia marcescens SM1 combined with abamectin (EMB) on black-winged subterranean termites

[0078] from Figure 3 It can be seen that after 7.75 × 10 8There was no significant difference in the corrected mortality rate of black-winged termites within 24 hours after treatment with CFU / mL SM1 and 0.02 mg / mL abamectin alone and in mixtures of various formulations. At 48 hours, the mortality rate was 7.75 × 10⁻⁶. 8 The corrected mortality rate of black-winged termites treated with a combination of CFU / mL SM1 and 0.02 mg / mL abamectin at a volume ratio of 5:1 showed a significant difference compared to the single-agent treatment group, and significant differences were observed between each combination treatment group and the single-agent treatment group between 72 h and 96 h.

[0079] Table 5. Toxicity determination of SM1 and abamectin combination against black-winged subterranean termites.

[0080]

[0081] Table 6. Co-toxicity coefficients of SM1 and abamectin combination with black-winged subterranean termites.

[0082]

[0083] As shown in Table 5, 7.75 × 10 8 CFU / mL SM1 against the LT of black-winged subterranean termite 50 The LT (time to death) of 0.02 mg / mL abamectin against black-winged subterranean termites was 74.26 h. 50 It is 105.21 hours. 7.75 × 10⁻⁶ 8 A mixture of CFU / mL SM1 and 0.02 mg / mL abamectin at a volume ratio of 9:1 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 42.17h; 7.75×10 8 A mixture of CFU / mL SM1 and 0.02 mg / mL abamectin at a volume ratio of 5:1 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 For 48.36 hours; 7.75 × 10 8 A 1:1 volume ratio of CFU / mL SM1 and 0.02 mg / mL abamectin was used to inhibit the LT (total toxicity) of black-winged termites. 50 It was 48.77 h; 7.75 × 10 8 A mixture of CFU / mL SM1 and 0.02 mg / mL abamectin at a volume ratio of 1:5 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 57.03 hours; 7.75 × 10⁻⁶ hours. 8 A mixture of CFU / mL SM1 and 0.02 mg / mL abamectin at a volume ratio of 1:9 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It is 45.56h.

[0084] Table 6 shows that, using SM1 as the standard reagent, the toxicity index of abamectin is 70.58. (The last part, "7.75 × 10," appears to be an unrelated fragment and is omitted from the translation.) 8When CFU / mL SM1 and 0.02 mg / mL abamectin are mixed at a volume ratio of 9:1, the actual toxicity index of the mixture is 176.10, the theoretical toxicity index is 97.06, and the co-toxicity coefficient is 181.43, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are combined at a volume ratio of 9:1, they exhibit synergistic toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about a specific concentration of 7.75 × 10⁻⁶.) 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are mixed in a 5:1 volume ratio, the actual toxicity index of the mixture is 153.56, the theoretical toxicity index is 95.10, and the co-toxicity coefficient is 161.47, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.02 mg / mL abamectin were combined at a volume ratio of 5:1, they exhibited synergistic toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about a specific concentration of 7.75 × 10⁻⁶.) 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are mixed in a 1:1 volume ratio, the actual toxicity index of the mixture is 152.27, the theoretical toxicity index is 85.29, and the co-toxicity coefficient is 178.52, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are combined in a 1:1 volume ratio, they exhibit synergistic toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about a specific concentration of 7.75 × 10⁻⁶ ppm.) 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are mixed at a volume ratio of 1:5, the actual toxicity index of the mixture is 130.21, the theoretical toxicity index is 75.49, and the co-toxicity coefficient is 172.50, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.02 mg / mL abamectin were combined at a volume ratio of 1:5, they exhibited synergistic toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about a specific concentration of 7.75 × 10⁻⁶.) 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are mixed at a volume ratio of 1:9, the actual toxicity index of the mixture is 162.99, the theoretical toxicity index is 73.52, and the co-toxicity coefficient is 221.69, which is much greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.02 mg / mL abamectin are combined at a volume ratio of 1:9, they exhibit synergistic toxicity against black-winged subterranean termites.

[0085] 4. Toxicity determination of Serratia marcescens SM1 combined with indoxacarb (IND) on black-winged subterranean termites

[0086] from Figure 4 It can be seen that after 7.75 × 10 8No significant differences were observed in the CFU / mL SM1 and 0.01 mg / mL indoxacarb single agents and mixtures of various agents in the black-winged termites treated at 24 h. Between 48 h and 96 h, the concentration of 7.75 × 10⁻⁶ mcg / mL was [not specified in the original text]. 8 The corrected mortality rates of the combination treatments (CFU / mL SM1 and 0.01 mg / mL indoxacarb at volume ratios of 1:1, 1:5, and 1:9) were significantly different from those of the single-agent treatments. 7.75 × 10⁻⁶ 8 The corrected mortality rate of the treatment group with a volume ratio of CFU / mL SM1 and 0.01 mg / mL indoxacarb of 9:1 was lower than that of the single-agent treatment group throughout the experiment.

[0087] As shown in Table 7, 7.75 × 10 8 CFU / mL SM1 against the LT of black-winged subterranean termite 50 The LT (Least Effectiveness) of 0.01 mg / mL indoxacarb against black-winged subterranean termites was 74.26 h; 50 It is 64.89 hours. 7.75 × 10⁻⁶ 8 A mixture of CFU / mL SM1 and 0.01 mg / mL indoxacarb at a volume ratio of 9:1 was used to inhibit the LT (limit effect) of black-winged subterranean termites. 50 It was 82.57 h; 7.75 × 10 8 A mixture of CFU / mL SM1 and 0.01 mg / mL indoxacarb at a volume ratio of 5:1 was used to inhibit the LT (limit effect) of black-winged subterranean termites. 50 It was 58.57 h; 7.75 × 10 8 A 1:1 volume ratio of CFU / mL SM1 and 0.01 mg / mL indoxacarb was used to treat the LT (Least Effective Rate) of black-winged termites. 50 It was 43.65 hours; 7.75 × 10⁻⁶ hours. 8 A mixture of CFU / mL SM1 and 0.01 mg / mL indoxacarb at a volume ratio of 1:5 was used to inhibit the LT (limit effect) of *Odontotermes acutissima*. 50 It was 42.79h; 7.75×10 8 A mixture of CFU / mL SM1 and 0.01 mg / mL indoxacarb at a volume ratio of 1:9 was used to inhibit the LT (limit effect) of *Odontotermes acutissima*. 50 It is 39.00h.

[0088] Table 7. Toxicity determination of SM1 and indoxacarb combination in black-winged subterranean termites.

[0089]

[0090] Table 8 shows that, using SM1 as the standard pesticide, the toxicity index of indoxacarb is 114.44. (When 7.75 × 10⁻⁶...) 8When CFU / mL SM1 and 0.01 mg / mL indoxacarb are mixed at a volume ratio of 9:1, the actual toxicity index of the mixture is 89.94, the theoretical toxicity index is 101.44, and the co-toxicity coefficient is 88.66, which is less than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb were combined at a volume ratio of 9:1, they exhibited additive toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm of SM1 and indoxacarb.) 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb are mixed at a volume ratio of 5:1, the actual toxicity index of the mixture is 126.79, the theoretical toxicity index is 102.41, and the co-toxicity coefficient is 123.81, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb were combined at a volume ratio of 5:1, the toxicity against black-winged subterranean termites was enhanced. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb are mixed at a 1:1 volume ratio, the actual toxicity index of the mixture is 170.13, the theoretical toxicity index is 107.22, and the co-toxicity coefficient is 158.67, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb are combined at a 1:1 volume ratio, the toxicity against black-winged subterranean termites is enhanced. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb are mixed at a volume ratio of 1:5, the actual toxicity index of the mixture is 173.55, the theoretical toxicity index is 112.03, and the co-toxicity coefficient is 154.91, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb were combined at a volume ratio of 1:5, the toxicity against black-winged subterranean termites was enhanced. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb are mixed at a volume ratio of 1:9, the actual toxicity index of the mixture is 190.41, the theoretical toxicity index is 113.00, and the co-toxicity coefficient is 168.51, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL indoxacarb are combined at a volume ratio of 1:9, the toxicity of the black-winged subterranean termite is enhanced.

[0091] Table 8. Co-toxicity coefficients of SM1 and indoxacarb in combination with black-winged subterranean termites.

[0092]

[0093] 5. Toxicity determination of Serratia marcescens SM1 combined with ivermectin (IVE) in black-winged subterranean termites

[0094] Depend on Figure 5 It can be seen that after 7.75 × 10 8 There was no significant difference in the corrected mortality rate of black-winged termites within 24 h after treatment with CFU / mL SM1 and 0.01 mg / mL ivermectin single agents and various mixtures; the mortality rate was 7.75 × 10⁻⁶ at 48 h and 72 h. 8 The corrected mortality rate was significantly different between the group treated with a 1:9 ratio of CFU / mL SM1 and 0.01 mg / mL ivermectin and the single-dose treatment group; after 96 hours, the mortality rate was 7.75 × 10⁻⁶. 8 The corrected mortality rates of the combined treatment groups with CFU / mL SM1 and 0.01 mg / mL ivermectin at volume ratios of 5:1 and 1:9 were significantly different from those of the single-dose treatment groups.

[0095] As shown in Table 9, 7.75 × 10 8 CFU / mL SM1 against the LT of black-winged subterranean termite 50 The LT (Long-Termite Length) of 0.01 mg / mL ivermectin against black-winged subterranean termites was 74.26 h. 50 It is 74.66 hours. 7.75 × 10⁻⁶ 8 A mixture of CFU / mL SM1 and 0.01 mg / mL ivermectin at a volume ratio of 9:1 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 65.11h; 7.75×10 8 A mixture of CFU / mL SM1 and 0.01 mg / mL ivermectin at a volume ratio of 5:1 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 59.98h; 7.75×10 8 A 1:1 volume ratio of CFU / mL SM1 and 0.01 mg / mL ivermectin was used to inhibit the LT (total toxicity) of black-winged termites. 50 It was 77.63 h; 7.75 × 10 8 A mixture of CFU / mL SM1 and 0.01 mg / mL ivermectin at a volume ratio of 1:5 was used to inhibit the LT (total toxicity) of black-winged subterranean termites. 50 It was 58.19 hours; 7.75 × 10⁻⁶ hours. 8 A mixture of CFU / mL SM1 and 0.01 mg / mL ivermectin at a volume ratio of 1:9 was used to inhibit the LT (Least Effective Rate) of black-winged subterranean termites. 50 It is 39.68h.

[0096] Table 10 shows that, using SM1 as the standard reagent, the toxicity index of ivermectin is 99.46. (When 7.75 × 10⁻⁶...) 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are mixed at a volume ratio of 9:1, the actual toxicity index of the mixture is 114.05, the theoretical toxicity index is 99.95, and the co-toxicity coefficient is 114.11, which is less than 120. Therefore, 7.75 × 108 When CFU / mL SM1 and 0.01 mg / mL ivermectin are combined at a volume ratio of 9:1, they exhibit additive toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are mixed at a volume ratio of 5:1, the actual toxicity index of the mixture is 123.81, the theoretical toxicity index is 99.91, and the co-toxicity coefficient is 123.92, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are combined at a volume ratio of 5:1, the toxicity against black-winged subterranean termites is enhanced. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are mixed in a 1:1 volume ratio, the actual toxicity index of the mixture is 95.66, the theoretical toxicity index is 99.73, and the co-toxicity coefficient is 95.92, which is less than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are combined at a 1:1 volume ratio, they exhibit additive toxicity against black-winged subterranean termites. (The text abruptly shifts to a seemingly unrelated topic about 7.75 × 10⁻⁶ ppm, which appears to be a typo and should be removed.) 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are mixed at a volume ratio of 1:5, the actual toxicity index of the mixture is 127.62, the theoretical toxicity index is 99.55, and the co-toxicity coefficient is 128.19, which is greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are combined at a volume ratio of 1:5, the toxicity against black-winged subterranean termites is enhanced. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are mixed at a volume ratio of 1:9, the actual toxicity index of the mixture is 187.15, the theoretical toxicity index is 99.52, and the co-toxicity coefficient is 188.05, which is much greater than 120. Therefore, 7.75 × 10 8 When CFU / mL SM1 and 0.01 mg / mL ivermectin are combined at a volume ratio of 1:9, they exhibit synergistic toxicity against black-winged subterranean termites.

[0097] Table 9. Toxicity determination of SM1 and ivermectin against black-winged subterranean termites.

[0098]

[0099]

[0100] Table 10. Co-toxicity coefficients of SM1 and ivermectin in black-winged subterranean termites.

[0101]

[0102] Toxicity determination of Serratia marcescens SM1 combined with lufenuron in Reticulitermes niger.

[0103] Table 11 shows that the concentration is 1×10 -2 1 mol / L Lufenuron for the LT of *Reticulitermes nigra* 50 It was 160.45 h; 8.75 × 10 10 CFU / mL SM1 against the LT of *Reticulitermes nigra* 50 It is 206.21h. 8.75×10 10 CFU / mL SM1 and 1×10 -2 mol / L chlorfenapyr compounded at a volume ratio of 2:1 for LT of Reticulitermes nigra 50 185.30h; 8.75×10 10 CFU / mL SM1 and 1×10 -2 mol / L chlorfenapyr compounded at a volume ratio of 1:1 with LT of Reticulitermes nigra 50 It was 113.62 h; 8.75 × 10 10 CFU / mL SM1 and 1×10 -2 mol / L chlorfenapyr compounded at a volume ratio of 1:2 for LT of Reticulitermes nigra 50 It is 86.49h.

[0104] Table 11. Toxicity determination of SM1 and lufenuron against *Reticulitermes nigra*.

[0105]

[0106] Table 12 Cotoxicity coefficients of SM1 and lufenuron in Reticulitermes nigra.

[0107]

[0108] Table 12 shows that, using lufenuron as the standard agent, the toxicity index of SM1 is 77.80. (8.75 × 10⁻⁶) 10 CFU / mL SM1 and 1×10 -2 When mol / L lufenuron is mixed at a volume ratio of 2:1, the actual toxicity index of the mixture is 111.24, the theoretical toxicity index is 85.20, and the calculated co-toxicity coefficient is 130.56, which is greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 1×10 - 2 When mol / L lufenuron is combined with other chlorfenapyr at a volume ratio of 2:1, its toxicity against *Reticulitermes nigra* is enhanced. (The text abruptly shifts to a seemingly unrelated statement about a concentration of 8.75 × 10⁻⁶ mol / L lufenuron.) 10 CFU / mL SM1 and 1×10 -2When mol / L lufenuron is mixed at a 1:1 volume ratio, the actual toxicity index of the mixture is 141.20, the theoretical toxicity index is 88.90, and the calculated co-toxicity coefficient is 158.82, which is much greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 1×10 -2 The toxicity of mol / L lufenuron combined with a 1:1 volume ratio of mol / L lufenuron to *Reticulitermes niger* has a synergistic effect. When 8.75 × 10⁻⁶ 10 CFU / mL SM1 and 1×10 -2 When mol / L lufenuron is mixed at a volume ratio of 1:2, the actual toxicity index of the mixture is 131.36, the theoretical toxicity index is 92.60, and the calculated co-toxicity coefficient is 141.86, which is much greater than 120, indicating that 8.75×10 10 CFU / mL SM1 and 1×10 -2 The toxicity of mol / L lufenuron combined with the product at a volume ratio of 1:2 to the black-breasted termite has a synergistic effect.

[0109] 7. Toxicity determination of Serratia marcescens SM1 combined with thiamethoxam to the black-breasted subterranean termite

[0110] Table 13 shows that 1×10 -2 1 mol / L thiamethoxam for the LT of black-breasted reticulotermite 50 179.99h; 8.75×10 10 CFU / mL SM1 against the LT of *Reticulitermes nigra* 50 It is 206.21h. 8.75×10 10 CFU / mL SM1 and 1×10 -2 Thiazinon at a volume ratio of 2:1 was used to treat LT of *Reticulitermes nigra*. 50 100.03h; 8.75×10 10 CFU / mL SM1 and 1×10 -2 Thiazinon at a volume ratio of 1:1 was used to treat LT of *Reticulitermes nigra*. 50 It was 85.03h; 8.75×10 10 CFU / mL SM1 and 1×10 -2 Thiazinon at a volume ratio of 1:2 was used to treat LT of *Reticulitermes nigra*. 50 It is 71.26h.

[0111] Table 13. Toxicity determination of SM1 and thiamethoxam against Reticulitermes nigra.

[0112]

[0113] Table 14. Co-toxicity coefficients of SM1 and thiamethoxam in *Reticulitermes nigra*.

[0114]

[0115] Table 14 shows that, using thiamethoxam as the standard reagent, the toxicity index of SM1 is 87.28. (8.75 × 10⁻⁶) 10 CFU / mL SM1 and 1×10 -2 When thiamethoxam at a volume ratio of 2:1 was mixed with mol / L thiamethoxam, the actual toxicity index of the mixture was 206.13, the theoretical toxicity index was 91.52, and the calculated co-toxicity coefficient was 225.23, which is much greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 1×10 -2 The toxicity of 2 mol / L thiamethoxam in combination with Reticula macranthae at a volume ratio of 2:1 has a synergistic effect on the toxicity of Reticula macranthae. When 8.75 × 10⁻⁶ 10 CFU / mL SM1 and 1×10 -2 When thiamethoxam at a 1:1 volume ratio is mixed with mol / L thiamethoxam, the actual toxicity index of the mixture is 211.68, the theoretical toxicity index is 93.64, and the calculated co-toxicity coefficient is 226.05, which is much greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 1×10 -2 The toxicity of 1 mol / L thiamethoxam in a 1:1 volume ratio combined with *Reticulitermes nigra* had a synergistic effect on the toxicity of *Reticulitermes nigra*. When 8.75 × 10⁻⁶ 10 CFU / mL SM1 and 1×10 -2 When thiamethoxam at a volume ratio of 1:2 is mixed with mol / L thiamethoxam, the actual toxicity index of the mixture is 119.32, the theoretical toxicity index is 95.76, and the calculated co-toxicity coefficient is 124.60, which is greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 1×10 - 2 The toxicity of mol / L thiamethoxam in combination with the black-breasted termite at a volume ratio of 1:2 has a synergistic effect.

[0116] 8. Toxicity determination of Serratia marcescens SM1 and Beauveria bassiana Bb in combination with Reticulitermes nigra var. nigra.

[0117] As shown in Table 15, 2.63 × 10 12 CFU / mL SM1 against the LT of *Reticulitermes nigra* 50 It was 16.71 hours; 2 × 10 8 Conidia / mL Bb against the LT of *Reticulitermes nigra* 50 It is 16.56 hours. 2.63 × 10⁻⁶ 12 CFU / mL SM1 and 2×10 8 Conidia / mL Bb, compounded at a volume ratio of 2:1, showed LT efficacy against *Reticulitermes nigra*.50 It is 9.93h; 2.63×10 12 CFU / mL SM1 and 2×10 8 Conidia / mL Bb, mixed at a 1:1 volume ratio, showed LT efficacy against *Reticulitermes nigra*. 50 It was 8.53 hours; 2.63 × 10 12 CFU / mL SM1 and 2×10 8 Conidia / mL Bb, compounded at a volume ratio of 1:2, showed LT efficacy against *Reticulitermes nigra*. 50 It takes 7.20 hours.

[0118] Table 15. Toxicity determination of SM1 and Bb against *Reticulitermes nigra*.

[0119]

[0120] Table 16 shows that, using SM1 as the standard reagent, the toxicity index of Bb is 100.88. (2.63 × 10⁻⁶) 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Bb is mixed at a volume ratio of 2:1, the actual toxicity index of the mixture is 168.20, the theoretical toxicity index is 100.29, and the co-toxicity coefficient is 167.71, which is much greater than 120. Therefore, 2.63 × 10 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Bb is combined at a volume ratio of 2:1, it exhibits synergistic toxicity against *Reticulitermes nigra*. (The text abruptly shifts to a seemingly unrelated topic about a concentration of 2.63 × 10⁻⁶). 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Bb is mixed at a volume ratio of 1:1, the actual toxicity index of the mixture is 195.78, the theoretical toxicity index is 100.44, and the co-toxicity coefficient is 194.92, which is much greater than 120. Therefore, 2.63 × 10 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Bb is combined at a volume ratio of 1:1, it exhibits synergistic toxicity against *Reticulitermes nigra*. When 2.63 × 10⁻⁶... 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Bb is mixed at a volume ratio of 1:2, the actual toxicity index of the mixture is 231.98, the theoretical toxicity index is 100.59, and the co-toxicity coefficient is 230.62, which is much greater than 120. Therefore, 2.63 × 10 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Bb is combined at a volume ratio of 1:2, it has a synergistic toxicity against Reticulitermes nigra.

[0121] Table 16. Co-toxicity coefficients of SM1 and Bb combined with *Reticulitermes nigra*.

[0122]

[0123] Toxicity determination of Serratia marcescens SM1 combined with Metarhizium anisopliae (Ma) in the black-breasted subterranean termite

[0124] As shown in Table 17, 2.63 × 10 12 CFU / mL SM1 against the LT of *Reticulitermes nigra* 50 It was 16.71 hours; 2 × 10 8 Conidia / mL Ma against the LT of *Reticulitermes nigra* 50 It lasted 38.02 hours. 2.63 × 10⁻⁶ 12 CFU / mL SM1 and 2×10 8 Conidia / mL Ma, formulated at a volume ratio of 2:1, showed LT efficacy against *Reticulitermes nigra*. 50 It is 9.33h; 2.63×10 12 CFU / mL SM1 and 2×10 8 Conidia / mL Ma, compounded at a volume ratio of 1:1, showed LT efficacy against *Reticulitermes nigra*. 50 It was 8.17h; 2.63×10 12 CFU / mL SM1 and 2×10 8 Conidia / mL Ma, formulated at a volume ratio of 1:2, showed LT efficacy against *Reticulitermes nigra*. 50 It takes 7.67 hours.

[0125] Table 17. Toxicity determination of SM1 and Ma against *Reticulitermes nigra*.

[0126]

[0127] Table 18 shows that, using SM1 as the standard reagent, the toxicity index of Ma is 43.94. (When 2.63 × 10⁻⁶...) 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Ma is mixed at a volume ratio of 2:1, the actual toxicity index of the mixture is 179.08, the theoretical toxicity index is 81.31, and the co-toxicity coefficient is 220.23, which is much greater than 120. Therefore, 2.63 × 10 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Ma is combined at a volume ratio of 2:1, it exhibits synergistic toxicity against *Reticulitermes nigra*. (The text abruptly shifts to a seemingly unrelated topic about a concentration of 2.63 × 10⁻⁶). 12 CFU / mL SM1 and 2×10 8When Conidia / mL Ma is mixed at a volume ratio of 1:1, the actual toxicity index of the mixture is 204.41, the theoretical toxicity index is 71.97, and the co-toxicity coefficient is 284.02, which is much greater than 120. Therefore, 2.63 × 10 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Ma is combined at a volume ratio of 1:1, it exhibits synergistic toxicity against *Reticulitermes nigra*. When 2.63 × 10⁻⁶... 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Ma is mixed at a volume ratio of 1:2, the actual toxicity index of the mixture is 217.72, the theoretical toxicity index is 62.63, and the co-toxicity coefficient is 347.64, which is much greater than 120. Therefore, 2.63 × 10 12 CFU / mL SM1 and 2×10 8 When Conidia / mL Ma is combined at a volume ratio of 1:2, it has a synergistic toxicity against Reticulitermes nigra.

[0128] Table 18. Co-toxicity coefficients of SM1 and Ma combined with *Reticulitermes nigra*.

[0129]

[0130] Toxicity determination of Serratia marcescens SM1 combined with ivermectin in Reticulitermes nigra (Black-breasted Termite).

[0131] As shown in Table 19, 8.75 × 10 10 CFU / mL SM1 against the LT of *Reticulitermes nigra* 50 The duration was 206.21 h, and the concentration of ivermectin was 5.71 × 10⁻⁶. -5 LT of *Reticulitermes nigra* at mol / L 50 It is 61.44 hours. 8.75 × 10 10 CFU / mL SM1 and 5.71×10 -5 When ivermectin at a volume ratio of 2:1 is combined with mol / L ivermectin, the LT (total thallium) of the black-breasted subterranean termite is [value missing]. 50 It was 20.40h; 8.75×10 10 CFU / mL SM1 and 5.71×10 -5 When ivermectin at a concentration of mol / L is mixed in a 1:1 volume ratio, its LT value against *Reticulitermes nigra* is [not specified]. 50 It was 19.18h; 8.75×10 10 CFU / mL SM1 and 5.71×10 -5 When ivermectin at a concentration of mol / L is mixed in a volume ratio of 1:2, its LT value against *Reticulitermes nigra* is [not specified]. 50 It is 23.63h.

[0132] Table 19. Toxicity determination of Serratia marcescens (SM1) and ivermectin against Reticulitermes nigra.

[0133]

[0134] Table 20 shows that, using ivermectin as the standard agent, the toxicity index of SM1 is 29.80. (8.75 × 10⁻⁶) 10 CFU / mL SM1 and 5.71×10 -5 When 1 mol / L ivermectin is mixed at a volume ratio of 2:1, the actual toxicity index of the mixture is 301.18, the theoretical toxicity index is 53.20, and the calculated co-toxicity coefficient is 566.12, which is much greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 5.71×10 -5 mol / L ivermectin, when combined with a volume ratio of 2:1, has a synergistic effect on the toxicity of *Reticulitermes niger*. When 8.75 × 10⁻⁶ 10 CFU / mL SM1 and 5.71×10 -5 When 1 mol / L ivermectin is mixed at a volume ratio of 1:1, the actual toxicity index of the mixture is 320.30, and the theoretical toxicity index is 64.90. The calculated co-toxicity coefficient is 493.53, which is much greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 5.71×10 -5 1 mol / L ivermectin, when combined with a 1:1 volume ratio, showed a synergistic effect on the toxicity of *Reticulitermes niger*. When 8.75 × 10⁻⁶ 10 CFU / mL SM1 and 5.71×10 -5 When 1 mol / L ivermectin is mixed at a volume ratio of 1:2, the actual toxicity index of the mixture is 259.98, the theoretical toxicity index is 76.60, and the calculated co-toxicity coefficient is 339.40, which is much greater than 120, indicating that 8.75 × 10 10 CFU / mL SM1 and 5.71×10 -5 The toxicity of 1 mol / L ivermectin combined with the product at a volume ratio of 1:2 to the black-breasted termite has a synergistic effect.

[0135] Table 20 Cotoxicity coefficients of *Serratia marcescens* (SM1) and ivermectin against *Reticulitermes nigra*.

[0136]

Claims

1. A compound pesticide for termite control based on Serratia marcescens, characterized in that, The compound pharmaceutical composition consists of *Serratia marcescens* and ivermectin, with the concentration of *Serratia marcescens* being 7.75 × 10⁻⁶. 8 The concentration of ivermectin is 0.01 mg / mL, and the volume ratio of the compound is 5:1, 1:5, or 1:

9.

2. A compound pesticide for controlling termites based on Serratia marcescens, characterized in that, The compound preparation has a strength of 8.75 × 10⁻⁶. 10 Serratia marcescens CFU / mL was combined with ivermectin at a volume ratio of 2:1, 1:1, or 1:

2.

3. The compound preparation according to claim 1 or 2, characterized in that, The termites mentioned are black-winged subterranean termites or black-breasted subterranean termites.

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