CN113711797B - Method for evaluating harmful leaf degree by counting tetranychus rubus - Google Patents

Abstract

The invention relates to the field of spider mite counting and harmful degree evaluation, and particularly discloses a method for evaluating rubber spider mites and indoor counting and harmful leaf degree, which comprises the following steps of: 1) Putting the collected spider mites and the rubber blades into a self-sealing bag, and before the self-sealing bag is put, dipping absorbent cotton in water to carry out moisture preservation treatment on petioles of the rubber blades; 2) Putting the self-sealing bag into a shady and ventilated light-proof breeding box and bringing the box back to the room; 3) Dipping ethyl acetate in absorbent cotton, and putting the absorbent cotton in a self-sealing bag to fumigate and kill spider mites; 4) After fumigating, taking the rubber leaves out of the self-sealing bag to count the mite number Q of the leaf surface; 5) Measuring the area s of the rubber blade; 6) Calculating the number Q of tetranychus urticae per unit area of the leaf, wherein Q = Q/s; 7) And evaluating the degree of the tetranychus rubus harming the leaves according to the q value. The method is simple and convenient to operate, the used tools are easy to obtain, the counting is accurate, the estimation method is novel, and the method can be used for rapidly monitoring and counting the number of the spider mites and evaluating the damage degree of the spider mites to leaves.

Description

Method for evaluating harmful leaf degree by counting tetranychus urticae

Technical Field

The invention relates to the field of spider mite counting and harmful degree evaluation, in particular to a method for evaluating the harmful leaf degree by counting rubber spider mites.

Background

Tetranychus, belonging to Tetranychidae of Euacaridae of Arachnida, is a kind of phytophagous harmful mites with tiny size and serious harm in agriculture and forestry. Tetranychus urticae grows on leaves, stems, roots and fruits of plants, and plant juice is sucked by a mouth needle to cause damage. The spider mites are one of the main pests harmful to rubber trees which are important economic crops in tropical and subtropical regions. At present, the tetranychus urticae in a gum planting area in Yunnan reaches 128 ten thousand mu, and the first main pest on natural rubber trees in Yunnan province is ridden. Tetranychus is harmful to rubber leaves, so that photosynthesis is weakened, tree growth is influenced, the whole leaves are withered and fall off when the tree grows seriously, cutting is stopped, the yield of rubber is influenced finally, and certain economic loss is brought to the natural rubber industry.

At present, the grading index for evaluating the degree of mites harmful leaves on a rubber tree is determined according to the traditional harmful characteristics, but the method has great limitation, the method can only evaluate the harmful degree of a certain specific harmful mite, the harmful degree of all harmful mites cannot be integrated, and factors such as actual number of harmful mites and the area of the mites harmful leaves need to be considered for objectively and accurately evaluating the harmful degree of rubber tetranychids.

However, the current method for counting the population of the tetranychus urticae is generally a field visual method with more defects. The disadvantages of this statistical method are: firstly, the tetranychus rubus lives on the rubber leaves higher off the ground, so that the tetranychus rubus is inconvenient to observe; secondly, the tetranychus itself is very active, the activity speed is high, and observation is inconvenient; thirdly, the tetranychus urticae is small in size, the body length is only 0.5mm or less, the tetranychus urticae is directly counted by naked eyes in a glue garden, and the error is large; fourth, counting outdoors increases the labor intensity of the operator, and counting for a long time may damage the operator's vision. At present, the tetranychus urticae is controlled by taking a green control road, namely, environment-friendly technical measures such as ecological regulation, physical control, biological control and scientific medicine application are preferably used for controlling the harm of the tetranychus urticae, however, no matter which control measure is adopted for controlling the tetranychus urticae, the insect population and the leaf damage degree of the tetranychus urticae need to be monitored and counted in advance, and further specific measures for controlling are made in a targeted manner. The common tetranychus on the rubber tree mainly comprises six-spotted spider mites, bihami-jacobsoni and oriental true spider mites, and the tetranychus all have the characteristics of quick reproduction, short development period and strong adaptability, so if the population number of the rubber tetranychus needs to be accurately counted, the counting is not accurate.

Therefore, it is an urgent need to solve the problem of the art to provide a convenient and fast method for evaluating the degree of harmful leaves with accurate counting and estimation.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for evaluating the harmful leaf degree by counting tetranychus urticae koch, so that the effects of at least achieving simple and convenient operation, low labor intensity, and capability of quickly and accurately counting the number of tetranychus urticae koch and evaluating the harmful leaf degree of tetranychus urticae koch are achieved.

The purpose of the invention is realized by the following technical scheme:

a method of assessing the extent of harmful foliage by counting tetranychus rubberus comprising the steps of:

1) Putting the collected rubber tetranychid and the rubber leaves into a self-sealing bag;

2) Putting the self-sealing bag into a shady and ventilated light-proof breeding box and bringing the box back to the room;

3) Fumigating and killing or fumigating Tetranychus coronarius by ethyl acetate;

4) Taking out the rubber leaves from the self-sealing bag, and counting the mite number Q of the leaf surfaces;

5) Measuring the area s of the rubber blade;

6) Measuring and calculating the number Q of rubber tetranychus in unit area, wherein Q = Q/s;

7) And (4) determining the grading index of the harmful leaf degree of the tetranychus urticae.

Wherein, the rubber tetranychidae has the light-resistant habit, and the tetranychidae can be prevented from escaping by keeping the rubber tetranychidae in a dark and breathable environment in the transportation process;

in addition, the traditional counting method is to directly count live mites in the field, but because the body size of the tetranychus urticae is small and the moving speed is high, the direct counting is difficult and inaccurate. Therefore, the method adopts a fumigating and killing method to kill the tetranychidae and count the tetranychidae indoors so as to reduce labor force, and a microscope can be used for counting indoors so as to increase counting accuracy. The method has the advantages that the spider mites can be killed by fumigating and killing, the corpses of the spider mites are not damaged, the spider mites after fumigating and killing are still attached to the leaves and are not prone to falling off, the number of leakage or repeated counting is avoided, and subsequent statistics is facilitated.

Further, in the step 1), before the rubber blades are placed in the valve bag, absorbent cotton is dipped in water to carry out moisture preservation treatment on the rubber blades and the leaf stalks.

The moisture-keeping treatment is to make the surfaces of the leaves and the petioles wet by water

Furthermore, a plurality of air holes are formed in the bag body of the self-sealing bag; the aperture of the air holes is less than 0.3mm; the self-sealing bag; the bag body is one side of the sealing strip of the self-sealing bag for containing objects.

If the air holes are not arranged, the temperature in the bag is too high or water vapor is generated, so that the spider mites escape from the leaf surface, and inaccurate counting is caused.

Further, in the step 2), the breeding box is refrigerated at the temperature of 3-5 ℃ if the breeding box is not counted immediately after being brought back indoors.

In order to make the statistical data more accurate and representative, a large number of samples are usually taken when counting tetranychus urticae in a large area, and sometimes the counting cannot be completed in a short period, while the breeding and development period of tetranychus urticae is extremely short, and about two days can be developed into larvae from eggs, so that the counting result may be inaccurate if the counting cannot be completed in a short period. In addition, spider mites cannot be fumigated before counting, because rubber spider mites are small and only a few hundred microns in size, and after death, the bodies quickly shrivel and weather, and are difficult to distinguish on leaf surfaces. Therefore, the method is used for refrigerating the tetranychidae at a low temperature before counting, so that the activity of the tetranychidae is reduced, and the effect of prolonging the counting period is achieved.

Further, in step 3), the fumigating or fumigating method for the dizziness comprises the following steps: dipping absorbent cotton with ethyl acetate, and placing the absorbent cotton in a self-sealing bag; the dosage of the ethyl acetate is 0.5-1mL of ethyl acetate dipped in each blade.

Further, the fumigating time is 15-25min.

Further, in the step 4), the number of the tetranychus mites is the total amount of eggs, young mites, nymphs and adult mites.

Further, in the step 5), before the area of the rubber blade is measured, the rubber blade is pressed to be flat.

Further, in the step 7), the number of the rubber spider mites in unit area is taken as the grading index of the harmful leaf degree of the rubber spider mites. The total of the diseases is classified into 5 grades, namely, the disease is mild (grade 1), the disease is mild (grade 2), the disease is moderate (grade 3), the disease is severe (grade 4) and the disease is severe (grade 5). The specific grading index is shown in Table 1.

TABLE 1

Extent of damage to leaves	Unit area (cm) 2 ) Tetranychus rubus number q
		Level 1 (light damage)	q＜0.2
Grade 2 (harm to lighter)	0.2≤q＜0.4
		Grade 3 (harms in)	0.4≤q＜0.6
Grade 4 (prejudicial to disease)	06≤q＜0.8
		Grade 5 (heavy hazard)	q≥0.8

The invention has the beneficial effects that:

1. the method has the advantages of low cost of required materials, simple and convenient operation method and capability of reducing the labor capacity of a counter.

2. The method has high counting accuracy, can quickly detect and count the number of the tetranychus urticae koch and evaluate the damage degree of the tetranychus urticae koch.

3. The method estimates the harmful leaf degree of the tetranychus urticae in the future week in advance, and provides a basis for guiding the glue garden to prevent and control the tetranychus urticae in production.

Detailed Description

The technical solutions of the present invention are described in further detail below, but the scope of the present invention is not limited to the following.

(1) Collection and collection of rubber spider mites

In the embodiment, sampling sites are located in Meng-Yangzheng Tanzhai (longitude and latitude N22 degrees 1.40 degrees, E100 degrees 49.97 degrees; sunny slope, elevation 766m, forest land is cutting forest) in Jinghong city of Yunnan province and rubber testing teams in Jiannan (longitude and latitude N22 degrees 1.85 degrees, E100 degrees 46.52 degrees; gentle slope, elevation 683m, forest land is cutting forest). And in the tetranychus urticae period, selecting two rubber forest lands with serious tetranychus urticae for investigation and sampling. Tetranychus rubulacea sampling site: middle and lower leaves of rubber tree. Respectively in rubber forests at two places, respectively shearing 1 front two canopy section branches in the east-west-north direction of a rubber tree by using a high branch shear, randomly selecting 5 complete leaves for each branch, observing and counting by naked eyes (a comparison group) in a rubber garden site, and then collecting the corresponding 5 leaves with spider mites by using the method of the invention (the leaves are placed in self-sealing bags with air holes, the self-sealing bags are sequentially placed in black holed insect rearing boxes, and box covers are replaced by sun-shading nets and covered).

(2) Temporary storage and fumigating killing of rubber spider mites

After the rubber tetranychid is brought back indoors, the breeding box is placed in a refrigerator cold room (4 ℃) for temporary storage, and a small group of absorbent cotton is dipped in a small amount of ethyl acetate and placed in a self-sealing bag for fumigating and killing the tetranychid for 20 minutes before counting;

(3) Tetranychus rubus count

After fumigating and killing, the rubber leaves with tetranychid mites are taken out by tweezers and placed under a stereoscopic microscope for counting the number of mites.

(4) Evaluation of degree of harmful leaf mites

Pressing the leaves with the spider mite number counted flatly, measuring the area s of each leaf by using an intelligent leaf area meter, then calculating the number of rubber spider mites in a unit area by using a formula Q = Q/s according to the number of the leaf spider mites on each leaf surface and the area of the corresponding leaves, and estimating the degree of the harmful rubber spider mites on the leaves according to the range of the Q value.

Taking a conventional traditional method, namely direct visual counting on the site of a rubber garden as a comparison example, the results of rubber spider mite counting and harmful leaf degree estimation of the rubber forest of Hepiazhai are shown in Table 2, and the results of rubber spider mite counting and harmful leaf degree estimation of the rubber forest of rubber test team in south Jiangnan are shown in Table 3.

TABLE 2

TABLE 3

Compared with the conventional method for directly counting the tetranychus in the rubber forest by naked eyes, the accuracy of the method is remarkably improved, in the embodiment, the average multiple of the counting ratio of the counting method and the conventional method reaches 3.72 times and 3.98 times, the condition that a large number of leakage exists in the conventional method for counting by naked eyes is shown, the reason is considered, the actual harmful condition of the tetranychus is difficult to accurately observe due to the fact that the movement of the tetranychus (causing observation and counting difficulty) and human errors of the naked eye observation are directly observed in a rubber garden by naked eyes, and the mobility of the tetranychus is reduced (reducing the transfer loss of the tetranychus) by measures such as shading, cooling, fumigating and the like, and the accuracy of the tetranychus counting can be remarkably improved by utilizing an instrument for observation in a laboratory. The method has the advantages that the estimation of the damage degree of the leaves according to the number of the spider mites in the unit area is more accurate, the damage degree of the spider mites in a short period can be estimated, and the problem of estimating the damage degree of the leaves when several kinds of harmful mites are damaged simultaneously is solved. The method has guiding significance for scientific accuracy of research (such as biological observation of tetranychus urticae or field observation of hazard characteristics) and comprehensive control (scientific control) of tetranychus urticae in production.

The foregoing is illustrative of the preferred embodiments of the present invention, and it is to be understood that the invention is not limited to the precise form disclosed herein and is not to be construed as limited to the exclusion of other embodiments, and that various other combinations, modifications, and environments may be used and modifications may be made within the scope of the concepts described herein, either by the above teachings or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (4)

1. A method for evaluating the degree of harmful leaves by counting tetranychus urticae, comprising the steps of:

1) Putting the collected rubber leaves with the tetranychidae into a self-sealing bag; the bag body of the self-sealing bag is provided with a plurality of air holes; the aperture of the air holes is less than 0.3mm; before the rubber blades are put into the valve bags, absorbent cotton is dipped in water to carry out moisture preservation treatment on the rubber blades and the leaf stalks;

2) Putting the self-sealing bag into a shady and ventilated light-proof breeding box and bringing the box back to the room; returning the breeding box to the room, and refrigerating the breeding box at 3-5 deg.C if the counting is not performed immediately;

3) Fumigating and killing or fumigating Tetranychus coronarius by ethyl acetate; the fumigating and killing or fumigating method for the dizziness comprises the following steps: dipping absorbent cotton with ethyl acetate, and placing the absorbent cotton in a self-sealing bag; the fumigating time is 15-25min;

4) Taking out the rubber leaves from the self-sealing bag to count the spider mite number Q;

5) Measuring the area s of the rubber blade;

6) Calculating the number Q of the tetranychus urticae in unit area of the leaves, wherein the calculation formula is Q = Q/s;

7) And evaluating the degree of the tetranychus rubus harming the leaves according to the q value.

2. The method of claim 1, wherein: in the step 4), the mouth number of the tetranychid mites is the total amount of eggs, young mites, nymphs and adult mites.

3. The method of claim 1, wherein: and 5) flattening the rubber blade before measuring the area of the rubber blade.

4. The method of claim 1, wherein: in step 7), the evaluation method comprises the following steps:

degree of damage to leaves Unit area (cm) ² ) Tetranychus urticae number q Level 1 (light damage) q＜0.2 Grade 2 (harm to lighter) 0.2≤q＜0.4 Grade 3 (harms in) 0.4≤q＜0.6 Grade 4 (prejudicial to disease) 0.6≤q＜0.8 Grade 5 (heavy hazard) q≥0.8

。