Method for preventing and controlling tomato leaf miners by using adult ladybird

Abstract

The invention discloses a method for preventing and controlling tomato leaf miners by using adult ladybirds, which comprises the following steps: preying larvae of the first, second and third instar of the tomato leaf miners in a submerged channel by using the adult ladybirds in a room, and preying the larvae of the first, second and third instar of the tomato leaf miners in the submerged channel by using the adult ladybirds; and in the field, releasing the ladybird adults by using a cage method to prevent and control the tomato leaf miners. According to the method, it is clear that the adult ladybird can prey on the first, second and third instar larvae of the tomato leaf miner in the subterranean channel, a Holding II type predation function reaction model is fitted, and a theoretical basis is provided for field release of the adult ladybird to prevent and control the tomato leaf miner. The field prevention and control effect of the heterodyea axyridis on the tomato leaf miner is defined, and a theoretical basis is provided for green prevention and control of the tomato leaf miner and further development and utilization of the heterodyea axyridis. According to the method, the heterodyea axyridis can be used as one of superior natural enemies for preventing and controlling the tomato leaf miners, the tomato leaf miners are prevented and controlled for a long time, pesticide pollution is reduced, pests are prevented from generating drug resistance, and a green prevention and control technology of agricultural pests is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of pest control, and more specifically to a method for preventing and controlling tomato leafminers using adult Coccinella polyphemus. Background Art

[0002] The tomato leafminer is a leaf-mining pest that can directly dig into leaves and bore into fruits in the form of larvae, causing huge economic losses to Solanaceae crops (such as tomatoes and eggplants) in my country. At present, my country mainly uses chemical pesticides to control tomato leafminers. However, due to the leaf-digging and fruit-boring characteristics of tomato leafminers, chemical control is not effective. With the extensive use of chemical agents, the resistance of tomato leafminers to various agents has become increasingly obvious (such as cartap and avermectin). Today, the control of tomato leafminers has become a major problem in my country's agriculture.

[0003] In order to better control the feeding and spread of tomato leafminers, it is necessary not only to strengthen pest inspection and quarantine and use fast-acting chemical control methods. It is also necessary to combine biological, physical and agricultural control measures, and use comprehensive control methods to more effectively control tomato leafminers. The biological control of tomato leafminers is to use the dominant predatory natural enemy in Xinjiang, Coccinella polymorpha, to control tomato leafminers, so that the population density of tomato leafminers is controlled below the economic threshold, and at the same time, it is better to avoid the emergence of drug resistance and environmental pollution. It is helpful to protect natural enemies and can achieve the effect of long-term control of tomato leafminers. Coccinella polymorpha is one of the dominant predatory natural enemies in Xinjiang and is widely distributed throughout Xinjiang. The survey found that the peak period of occurrence of Coccinella polymorpha and tomato leafminers overlaps a lot, and it is the dominant predatory natural enemy in tomato greenhouses. It is very likely to be a potential predatory natural enemy of tomato leafminers. Due to the irrational use of chemical agents, the problem of pest resistance is becoming more and more serious. The tomato leafminer has developed resistance to insecticides such as cypermethrin, permethrin, and methyl parathion. At the same time, natural predators are also harmed, and in severe cases, even a large number of natural enemies die.

[0004] In the related art disclosed in the past, the 1st instar larvae and 2nd instar larvae of tomato leafminer were tested respectively, and the density of the 1st instar larvae of tomato leafminer was set at 20, 40, 60, 80 and 100 heads / dish, and the density of the 2nd instar larvae was set at 10, 30, 50, 70 and 90 heads / dish, respectively, and 5 replicates were set for each density. Before the test, the 4th instar larvae of Harmonia axyridis and Propylaea japonica with uniform age and agility were selected and placed in a culture dish (3.50 cm in diameter and 1.50 cm in height) for starvation treatment for 24 hours. On the day of the experiment, a layer of moistened filter paper was laid on the bottom of the culture dish. Ten 0.50 cm × 0.50 cm leaf discs cut from fresh tomato leaves were evenly placed on each dish for tomato leafminers to feed on. Then, tomato leafminer larvae of different densities were inoculated with a fine brush, and then the fourth-instar larvae of single-headed (Axyridis axyridis / Propylaea punctata) after starvation treatment were inoculated. The dish was sealed with plastic wrap, and several dense small holes were pierced on the plastic wrap with a No. 3 insect needle for ventilation. The dish was placed in an artificial climate box for culture. After 24 hours, the number of tomato leafminer larvae with intact insect bodies remaining in each dish was counted under a dissecting microscope. However, this method is to pick out the tomato leafminer larvae from the burrows, which does not conform to the natural conditions in the field. In the field, tomato leafminer larvae are in the burrows of leaves except when they turn to leaves to cause damage and when mature larvae enter the soil to pupate.

[0005] In view of the above-mentioned deficiencies, it is an urgent problem to be solved by the present invention to find a local dominant natural enemy insect that can carry out long-term control of tomato leafminer, prevent tomato leafminer from developing pesticide resistance, reduce the damage of pesticides to natural natural enemies, and maintain a balanced state of insect diversity. Summary of the invention

[0006] Based on the above analysis, the important problem solved by the present invention is to clarify the predatory functional response of the adult Coccinella multicolor to the larvae of tomato leafminer in the duct, and to conduct cage experiments in the field to clarify the field control effect of the adult Coccinella multicolor, the dominant predatory natural enemy in Xinjiang, on tomato leafminer, providing theoretical support for the green control of tomato leafminer and the further development and utilization of Coccinella multicolor.

[0007] The present invention is achieved by the following technical means:

[0008] The present invention first discloses a method for controlling tomato leafminer by using adult Coccinella polyphemus, comprising the following steps:

[0009] (1) Indoors, adult Coccinella heteroptera are used to prey on larvae of tomato leafminers in the tunnels;

[0010] (2) In the field, adult Coccinella multiflora is released by cage method to control tomato leafminer.

[0011] Furthermore, step (1) comprises the following steps:

[0012] Collect and feed Coccinella heteroptera;

[0013] The larvae of tomato leafminer were collected, including 1st instar larvae, 2nd instar larvae and 3rd instar larvae.

[0014] Furthermore, the collecting of Coccinella heterostes comprises:

[0015] Pairs of adult Coccinella polymorpha were collected from the weeds of the Convolvulaceae family around tomatoes at the Kuklanmu Vegetable Base in Kaerdun Township, Yining County, Ili Kazakh Autonomous Prefecture.

[0016] Furthermore, the feeding of the multi-coloured ladybird comprises:

[0017] The collected pairs of Coccinella heteroptera were placed in self-made insect cages and fed with aphids to establish experimental populations.

[0018] Furthermore, the collecting of tomato leafminer larvae comprises:

[0019] On the day of the experiment, the larvae of tomato leafminers were collected from the tomato greenhouse and brought back to the laboratory with the leaves. The larvae of tomato leafminers were cut according to the instars (1st, 2nd, and 3rd instars) and the leaves were used in the experiment.

[0020] A layer of wet cotton was spread on the bottom of a petri dish with a diameter of 9 cm and a height of 1.5 cm, and then a layer of wet filter paper was spread on the cotton. The larvae of tomato leafminer cut according to age were divided into the petri dishes according to different ages (1, 2, 3) and different densities (20, 40, 60, 80, 100 heads / dish) for experiments;

[0021] Adult Coccinella heteroptera of the same age were selected from the experimental population and placed individually in a culture dish for 24 hours of starvation treatment;

[0022] Adult Coccinella heterostes that had been starved for 24 hours were placed in a pre-prepared culture dish containing tomato leafminer larvae for a predation experiment, and the number of complete tomato leafminer larvae was observed under a stereomicroscope after 24 hours.

[0023] Further, step (2) comprises the following steps:

[0024] Collect adult Coccinella heteroptera;

[0025] Selection is made for the desired tomato plants for release.

[0026] Furthermore, collecting Coccinella heteroptera includes:

[0027] Mating adult Coccinella heterostes were collected from outdoor Convolvulaceae weeds, placed in pairs in petri dishes and starved for 24 hours before release into the field.

[0028] Further, the selecting of the desired tomato plants for release comprises:

[0029] Randomly select tomato plants with the same growth in the same greenhouse, and use insect-proof nets with length, width and height of 0.5m, 0.5m and 0.86m to cover single plants. Before covering, according to the best benefit-harm ratio of indoor adult Coccinella multicolor to the predation function response of tomato leafminers of different ages in the channel, the same number of 1st, 2nd and 3rd instar larvae of tomato leafminers were artificially inoculated on tomatoes, among which Coccinella multicolor adults: 1st instar larvae (tomato leafminers) = 1:80; Coccinella multicolor adults: 2nd instar larvae (tomato leafminers) = 1:40; Coccinella multicolor adults: 3rd instar larvae (tomato leafminers) = 1:20. After covering, they were numbered for field release;

[0030] A pair of adult Coccinella heterostes that had been starved for 24 hours was placed in each cage of the treatment group for the experiment, while no ladybugs were placed in the cage of the control group. The population changes of tomato leafminers were observed at 5d, 7d, 14d, 21d and 30d.

[0031] The beneficial effects of the present invention are:

[0032] 1. It was confirmed that the adult Coccinella multicolor can prey on the 1st, 2nd and 3rd instar larvae of tomato leafminer in the tunnel, and the Holling II predation functional response model was fitted, providing a theoretical basis for the field release of adult Coccinella multicolor to control tomato leafminer;

[0033] 2. Secondly, the field control effect of Coccinella multicolor on tomato leafminer (1st, 2nd and 3rd instar larvae) was clarified, providing a theoretical basis for the green control of tomato leafminer and the further development and utilization of Coccinella multicolor;

[0034] 3. The present invention is conducive to using Coccinella multicolor as one of the dominant natural enemies of tomato leafminer, long-term prevention and control of tomato leafminer, reducing pesticide pollution, avoiding the development of pesticide resistance in pests, facilitating wide promotion and demonstration applications, and contributing to green control technology of agricultural pests. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0036] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0037] Example 1

[0038] A method for controlling tomato leafminer by using adult Coccinella polyphemus, comprising the following steps:

[0039] (1) Pairs of adult Coccinella heterostemons were collected from weeds of the Convolvulaceae family around tomatoes at the Kuklanmu Vegetable Base in Kaerdun Township, Yining County, Ili Kazakh Autonomous Prefecture; the collected pairs of Coccinella heterostemons were placed in self-made insect cages and fed with aphids to establish an experimental population;

[0040] (2) On the day of the experiment, tomato leafminer larvae were collected from the tomato greenhouse and brought back to the laboratory with the leaves. The tomato leafminers were cut off with leaves according to the age (1, 2, and 3) for the experiment; a layer of wet cotton was spread on the bottom of a culture dish with a diameter of 9 cm and a height of 1.5 cm, and then a layer of wet filter paper was spread on the cotton. The tomato leafminer larvae cut according to the age were divided into culture dishes according to different ages (1, 2, and 3) and different densities (20, 40, 60, 80, and 100 heads / dish) for the experiment; multi-heteromorph adults of the same age were selected from the experimental population, and placed individually in a culture dish for 24 hours of starvation treatment; multi-heteromorph adults that had been starved for 24 hours were placed in a culture dish containing tomato leafminer larvae prepared in advance for predation experiments, and the number of intact tomato leafminer larvae was observed under a stereomicroscope after 24 hours;

[0041] (3) Collect mating adult Coccinella heterostemons from outdoor Convolvulaceae weeds, place them in pairs in petri dishes, starve them for 24 hours, and release them into the field;

[0042] (4) Randomly select tomato plants with the same growth in the same greenhouse, and use insect-proof nets with length, width and height of 0.5m, 0.5m and 0.86m to cover the individual plants. Before covering, artificially inoculate the tomatoes with the same number of 1st, 2nd and 3rd instar larvae of tomato leafminers according to the optimal benefit-harm ratio of indoor Coccinella heterospora to the predation function of tomato leafminers in the channel. The optimal benefit-harm ratio is: Coccinella heterospora adults: 1st instar larvae (tomato leafminers) = 1:80; Coccinella heterospora adults: 2nd instar larvae (tomato leafminers) = 1:40; Coccinella heterospora adults: 3rd instar larvae (tomato leafminers) = 1:20. After the covering is completed, the plants are numbered for field release; a pair of Coccinella heterospora adults that have been starved for 24 hours are placed in the cages of the treatment group for the experiment, and no ladybugs are placed in the cages of the control group. The population changes of tomato leafminers at 5d, 7d, 14d, 21d and 30d are observed.

[0043] Test Example 1

[0044] Experiment on the predatory functional response of Coccinella multicolor adults to the 1st, 2nd and 3rd instar larvae of tomato leafminer in the tunnel.

[0045] The experiment was conducted on the 1st, 2nd and 3rd instar larvae of tomato leafminers. Before the experiment, the adults of Coccinella variegata with the same age and agility were selected and starved for 24 hours. On the day of the experiment, the larvae of tomato leafminers were collected from the tomato greenhouse and brought back to the laboratory with the leaves. The tomato leafminers were cut off with leaves according to their ages for the experiment. During the experiment, a layer of wet cotton was spread on the bottom of the culture dish, and then a layer of wet filter paper was spread on the cotton. The leaves with tomato leafminers were placed in the corresponding culture dishes according to the ages (1st, 2nd and 3rd instars) and densities (20, 40, 60, 80 and 100 heads / dish) required for the experiment. After the placement was completed, a Coccinella variegata adult and a 3rd instar larvae that had been starved for 24 hours were placed in each culture dish for the experiment. After 24 hours, the number of complete tomato leafminer larvae was observed under a stereomicroscope. And recorded. Each treatment was repeated 3 times.

[0046] (1) Predatory functional response of adult Coccinella polyphemus to 1st, 2nd, and 3rd instar larvae of tomato leafminer in the tunnel

[0047] The predation functional response of adult Coccinella polymorpha to 1st, 2nd and 3rd instar larvae of tomato leafminer and the related parameters were fitted by using the Holling II predation functional response model as shown in Table 1. The instantaneous attack rate of Coccinella polymorpha to 1st, 2nd and 3rd instar larvae of tomato leafminer in the channel was 9.967, 4.2707 and 3.2323, showing that the instantaneous attack rate decreased with the increase of larval age. The time required to deal with a 1st, 2nd and 3rd instar larvae was 0.0024, 0.0214 and 0.0363, respectively, showing that the treatment time increased with the increase of larval age. The theoretical maximum daily predation amount of 1st, 2nd and 3rd instar larvae was 416.67, 46.73 and 27.55, showing that the predation amount decreased with the increase of age.

[0048] Table 1 Predation function equation and response parameters of Coccinella polymorpha adults on young larvae of tomato leafminer in the tunnel

[0049]

[0050] Note: Na is the number of prey eaten; N is the initial density of prey.

[0051] The parameters obtained by fitting the Holling II predator-prey functional response model were used to estimate the search effect S of the adult Coccinella multicolor on the 1st, 2nd and 3rd instar larvae of tomato leafminer according to the prey density. The search effect of Coccinella multicolor on the young larvae of tomato leafminer in the tunnel is shown in Table 2, showing that the search effect decreases with the increase of density and increases with the increase of age.

[0052] Table 2 The search effect of adult Coccinella polymorpha on young larvae of tomato leafminer in the tunnel

[0053]

[0054] Test Example 2

[0055] Field cage release experiment of Coccinella heterospora adults

[0056] In the tomato planting area, a greenhouse with consistent growth of tomatoes, cultivation conditions, water, fertilizer, soil type, etc. was selected for the experiment. Tomato plants were randomly selected in the greenhouse. The tomato plants were in the early stage of flowering and fruiting. The height of the tomato plants was between 70-80 cm. A control group and a treatment group were set up. A 60-mesh insect-proof net was used to cover the plants to prevent external insects from entering. Each insect-proof net covered a tomato plant as a treatment. Before releasing the multi-spotted ladybird, the same number of 1st, 2nd, and 3rd instar larvae of tomato leafminers were artificially inoculated on tomatoes according to the best benefit-harm ratio of indoor multi-spotted ladybirds to the predation function response of tomato leafminers in the channel. Treatment group: each treatment released a pair of multi-spotted ladybird adults. If multi-spotted ladybirds were found dead in the later investigation, they could be supplemented. Control group: no multi-spotted ladybird was released. Three replicates were set for both the control group and the treatment group. The population of tomato leafminers on the whole plant was counted at 5d, 7d, 14d, 21d, and 30d after treatment, and the insect population reduction rate was calculated.

[0057] As shown in Table 3, the adult Coccinella multicolor has a good field control effect on the 1st, 2nd and 3rd instar larvae of tomato leafminer, and the control effect gradually becomes significant with the increase of release days. The control effect of adult Coccinella multicolor on the 1st instar larvae of tomato leafminer can reach 53.85%, the control effect on the 2nd instar larvae can reach 59.40%, and the control effect on the 3rd instar larvae can reach 93.58%. The field control effect on the 3rd instar larvae of tomato leafminer is the best, showing that the control effect is getting better and better with the increase of larval age. With the increase of release days, there is a significant difference between the field control effect of the 3rd instar larvae of tomato leafminer and the control effect of the 1st and 2nd instar larvae (P<0.05). The research results show that the adult Coccinella multicolor has a good control effect on the larvae of tomato leafminer and can be further developed and utilized as a natural enemy of tomato leafminer.

[0058] Table 3 The control effect of releasing adult Coccinella heteroptera against larvae of tomato leafminer

[0059]

[0060] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for controlling tomato leafminer by using adult Coccinella polyphemus, comprising: (1) Indoors, adult Coccinella heteroptera are used to prey on larvae of tomato leafminers in the tunnels; (2) In the field, adult Coccinella multiflora is released by cage method to control tomato leafminer.

2. The method according to claim 1, wherein: The step (1) comprises the following steps: Collecting Coccinella heterostemona, placing the collected pairs of Coccinella heterostemona in a self-made insect cage, feeding them with aphids, and establishing an experimental population; Cut the tomato leafminers from the tomato greenhouse according to their ages and leaves, spread a layer of wet cotton on the bottom of the culture dish, and then spread a layer of wet filter paper on the cotton, and pack the tomato leafminers of different ages into the culture dish according to different densities; Adults of the same age were selected from the experimental population, placed individually in a culture dish for starvation treatment, and then placed in a culture dish containing tomato leafminer larvae prepared in advance for a predation experiment. After 24 hours, the number of complete tomato leafminer larvae was observed under a stereomicroscope.

3. The method according to claim 2, wherein: The tomato leaf miners of different ages include: 1st instar larvae, 2nd instar larvae, and 3rd instar larvae.

4. The method according to claim 2, wherein: The different densities include: 20 heads / dish, 40 heads / dish, 60 heads / dish, 80 heads / dish, and 100 heads / dish.

5. The method according to claim 2, wherein: The starvation treatment time is 24 hours.

6. The method according to claim 1, wherein: The step (2) comprises the following steps: The mating adult Coccinella heterostemona was collected from the outdoor Convolvulaceae weeds, and the pairs were placed in petri dishes for starvation treatment, and then released into the field; Tomato plants with the same growth were randomly selected in the same greenhouse, and single plants were covered with insect-proof nets. Before covering, the same number of 1st, 2nd and 3rd instar larvae of tomato leafminers were artificially inoculated on tomatoes according to the optimal benefit-harm ratio of the predation functional response of the indoor Coccinella heterospora adults to the predation of tomato leafminers of different ages in the channel. After covering, the larvae were numbered for field release; A pair of adult Coccinella heterostes that had been starved for 24 hours was placed in each cage of the treatment group for the experiment, while no ladybugs were placed in the cage of the control group. The population changes of tomato leafminers were observed at 5d, 7d, 14d, 21d and 30d.

7. The method according to claim 6, wherein: The starvation treatment time is 24 hours.

8. The method according to claim 6, wherein: The optimal benefit-harm ratio of the indoor Coccinella multicolor adults to the predation functional response of tomato leafminers of different ages in the channel is: Adult of Coccinella multicolor: 1st instar larva = 1:80; Adult of Coccinella multicolor: 2nd instar larva = 1:40; The ratio of adult Coccinella multicolor: 3rd instar larvae = 1:20.

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