CN114982721A

CN114982721A - Rapid propagation method of lygus lucorum

Info

Publication number: CN114982721A
Application number: CN202210523499.9A
Authority: CN
Inventors: 张利娟; 张琦; 罗泉; 郭线茹; 赵曼; 李为争; 王高平
Original assignee: Henan Agricultural University
Current assignee: Henan Agricultural University
Priority date: 2022-05-13
Filing date: 2022-05-13
Publication date: 2022-09-02

Abstract

The invention provides a rapid propagation method of lygus lucorum, and relates to the technical field of artificial feeding of insects. The invention uses fresh corn ear blocks and corn kernels as main feeding raw materials, has low cost, is not limited by seasons, saves space, time and labor, has simple operation, can carry out large-scale and standardized feeding, and can quickly establish population. By utilizing the method, the lygus lucorum egg blocks are laid on the inner side of the seed coats at the base parts of the corn grains, and the emerald green egg blocks are in sharp contrast with the yellowish white corn grains, so that the egg blocks are convenient to collect and observe for hatching. By feeding, the survival rate, the egg laying amount, the hatching rate and the like of the lygus lucorum show better effects. The invention can quickly and simply collect the egg masses, accurately check the number of the egg masses, save time and have important significance for researching the individual growth and development rules, the basic biological characteristics such as the reproductive capacity of adults and the like, screening prevention and treatment medicaments, making the measurement and the prevention and treatment strategies in a targeted way and the like.

Description

Rapid propagation method of lygus lucorum

Technical Field

The invention belongs to the technical field of artificial feeding of insects, and particularly relates to a method for rapidly propagating lygus lucorum.

Background

Insects of lygus lucorum of lygus hemiptera of lygus lucorum are widely distributed in domestic wheat and corn production areas, and host plants comprise crops such as wheat, corn, cotton, sorghum, oat, beet and the like and various gramineous weeds, and the host juice is absorbed by adult and nymphs to influence the growth and development of hosts. The lygus lucorum has strong ecological adaptability, and the occurrence degree and the occurrence frequency of the lygus lucorum show an aggravation trend.

The research on artificial feeding of the lygus lucorum is less at home and abroad, and a large amount of insect sources are needed for screening proper control medicaments, so that the exploration of the feeding method of the lygus lucorum has important significance for researching the individual growth and development rules, basic biological characteristics such as adult fertility and the like, screening control medicaments, making the detection and control strategies in a targeted manner and the like. The lygus lucorum has small body and strong activity, which causes certain difficulty for indoor artificial feeding. In the past, fresh wheat seedlings are mainly used for feeding and collecting egg masses, but the wheat cultured indoors is easy to mildew, so that the hatching rate of lygus lucorum eggs is reduced. And because the lygus lucorum egg blocks are emerald green and have similar color with wheat seedlings, and the egg blocks are produced in the stem tissues, the egg blocks on the wheat seedlings are very difficult, and the observation of the egg amount can be finished by means of a dissecting mirror. Meanwhile, the egg mass is laid in the stem and leaf tissue of the wheat seedling, and the collection of the egg mass is difficult.

Disclosure of Invention

In view of the above, the invention aims to provide a method for rapidly propagating lygus lucorum, which can rapidly and simply collect egg masses, accurately check the number of the egg masses and egg granules, save time, and facilitate the mass propagation of populations and then continue to be used for other experimental researches such as screening of control agents.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a method for rapidly propagating lygus lucorum, which comprises the following steps: (1) placing the adult lygus lucorum into a device containing fresh corncob blocks for culturing, and collecting egg blocks every day after egg laying;

(2) putting the egg masses collected in the step (1) into a device containing fresh corn kernels for hatching to obtain nymphs;

(3) and (3) transferring the nymphs obtained in the step (2) to a device containing fresh corn ear blocks for culture, and obtaining the adult lygus lucorum after 5 molting.

Preferably, the fresh corn ear blocks in the steps (1) and (3) are both from fresh fruit-eating corn, waxy corn in the grain filling stage or kernel corn in the grain filling stage;

and (3) the fresh corn kernels in the step (2) are derived from fresh fruit-eating corn, waxy corn in the grain filling stage or kernel corn in the grain filling stage.

Preferably, the device in step (1) and step (3) has a larger size than the device in step (2).

Preferably, the device in steps (1) to (3) is a gas-permeable and transparent device;

and (3) paving 1-2 layers of absorbent paper at the bottom of the device.

Preferably, the conditions for culturing in step (1) and step (3), and incubating in step (2), comprise: the temperature is 25 +/-1 ℃, the relative humidity is 65 +/-5%, and the photoperiod is 16 hours of light and 8 hours of dark.

Preferably, the fresh corn ear block comprises the steps of removing bracts from the fresh corn ear, cutting the fresh corn ear into corncobs along gaps between adjacent corn kernels, each corncob containing 10-30 corn kernels, stripping off incomplete corn kernels at the cut positions, and wiping off slurry flowing out of the corn kernels.

Preferably, the fresh corn ear block is replaced every 3-4 days during the culture in the step (1) and the step (3).

Preferably, the fresh corn kernels are replaced every 1-2 days during the incubation in the step (2).

Preferably, the ratio of male to female of the adult lygus lucorum in the step (1) is 1: 1.5-2.

Has the beneficial effects that: the invention provides a method for rapidly propagating lygus lucorum, which utilizes fresh corn ear blocks and corn kernels as main feeding raw material bodies, fresh corns are continuously purchased in the market all year round, can be stored in a normal-temperature refrigerator for 10-15 days once, are low in cost and free from season limitation, saves space, time and labor required by wheat seedling planting, is simple to operate, can be fed in a large-scale and standardized manner, and can rapidly establish a population. The invention utilizes corn to artificially feed lygus lucorum, which is the first example of the domestic artificial feeding technology of lygus lucorum. By utilizing the method, the lygus lucorum egg blocks are laid on the inner side of the seed coats at the base parts of the corn grains, and the emerald green egg blocks are in sharp contrast with the yellow-white corn grains, so that the egg blocks are convenient to collect and observe for hatching. By feeding, the survival rate, the egg laying amount, the hatching rate and the like of the lygus lucorum show better effects. The invention can quickly and simply collect the egg masses, accurately check the number of the egg masses, save time and have important significance for researching the individual growth and development rules, the basic biological characteristics such as the reproductive capacity of adults and the like, screening prevention and treatment medicaments, making the measurement and the prevention and treatment strategies in a targeted way and the like.

Drawings

FIG. 1 shows the eggs and egg laying positions of lygus lucorum;

fig. 2 is the hatching rate and the nymph survival rate of the lygus lucorum eggs, and the data in the graph are mean values ± sem, which indicates that the difference is significant by multiple comparisons of ANOVATukey's (P < 0.05);

FIG. 3 shows the daily egg laying amount and egg laying block number of lygus lucorum in the egg laying period;

FIG. 4 shows the day-by-day oviposition of adult females.

Detailed Description

According to the invention, the adult Leptochloporus lucorum is cultured in a device containing fresh corn ear blocks, and the egg blocks are collected every day after egg laying. The adult is preferably collected from a field where the lygus lucorum is hosted, such as a field where corn and other host fields are collected by using an insect catching net or an insect sucking device. When the adult insects are cultured, the adult insects are preferably placed in a medium-sized insect breeding box, 1-2 layers of absorbent paper are laid at the bottom of the box, and therefore the adult insects can be conveniently and timely replaced, and the mildew generated in the box can be cleaned; and then a plurality of bent filter paper strips are put in the container for the movement of the red plant bug. The type of the absorbent paper is not particularly limited in the present invention, and preferably includes filter paper, toilet paper, or paper towel capable of rapidly absorbing moisture. The size, the capacity and the material of the medium-sized insect breeding box are not particularly limited, only the requirements of good air permeability and transparent color are met, the observation is facilitated, and in the embodiment, the columnar insect breeding box with the diameter of 10.2cm and the height of 6.5cm is preferred, but the columnar insect breeding box cannot be regarded as the whole protection range of the invention. The invention takes fresh corn ear blocks as food and oviposition media of adult lygus lucorum, the fresh corn ear blocks are preferably derived from fresh-eating fruit corn, waxy corn in grain filling stage or grain corn in grain filling stage, the examples take fresh-eating fruit corn as an example for illustration, but the fresh-eating fruit corn cannot be regarded as the full protection scope of the invention. The corn ear block is preferably prepared by removing bracts from a fresh corn ear, cutting the corn ear block with corn ear cores into corn blocks along gaps between adjacent corn kernels by using a cutter, wherein each corn block contains 10-30 corn kernels, the corn kernels with incomplete cuts are peeled off, and pulp flowing out of the corn kernels is wiped off by using absorbent paper.

According to the invention, collected adults are placed in the medium-sized insect breeding box, 6-8 adults are preferably placed in each box, the ratio of male to female is close to 1: 1.5-2, paired breeding is carried out, the opening of the insect breeding box is covered by a 100-mesh nylon mesh cloth, and the nylon mesh cloth is tightly sealed by a rubber band. The adult cultivation is preferably carried out in an artificial climate box, and the temperature is set to be 25 +/-1 ℃, the relative humidity is set to be 65 +/-5%, and the light cycle is set to be 16: 8 (L: D), changing the corn blocks every 3 days.

According to the method, egg masses are collected after the adult mating and egg laying, preferably, female insects lay eggs after 4-5 days after the adult mating, and eggs are collected once every morning at about 10 o' clock. In the invention, the egg mass is mostly produced on the inner side of the seed coat at the base of the corn kernel, and the egg mass generally comprises 4-8 eggs, at most 19 eggs, which are arranged in parallel. The collection of the egg mass of the present invention preferably comprises: the corn kernels with the egg masses were gently pulled (sheared) from the base with forceps or scissors and then placed into a small insect-raising box (diameter 3.7cm, height 3.3 cm). If moisture is generated in the box, the box is wiped in time so as to prevent the newly hatched nymphs from being stuck to cause death. The method has the advantages that the laying period of the lygus lucorum is 10-12 days, the average laying of a single female is 70-80 grains in a whole life, the female gradually dies after 11 days of laying, the average service life of the female adults is 16 days, and the average service life of the male adults is 14 days.

After the egg blocks are collected, the invention puts the egg blocks collected every day into a device containing fresh corn kernels for hatching to obtain nymphs. The invention preferably incubates in the small insect breeding box, a plurality of complete fresh corn kernels are preferably placed in the small insect breeding box in advance, and the corn kernels are replaced once every two days. The incubation parameters of the invention are preferably the same as those of the culture, and are not repeated herein, and when the feeding temperature of the eggs is adjusted up to 1-2 ℃, the incubation time of the eggs can be accelerated, and is shortened by 1-2 days on average. According to the invention, at the temperature of 25 +/-1 ℃, the eggs are hatched for about 7-8 days, and the average hatchability is 81.13%.

After the eggs are hatched, the nymphs are transferred to a device containing fresh corn ear blocks for culture, and the adult lygus lucorum is obtained after 5 molting. The cover of the small-sized insect-culturing box containing the primarily hatched nymphs is preferably opened and the nymphs are transferred to a new large-sized insect-culturing box (35 x 25 x 16cm) for culturing, and the culture parameters are preferably the same as those in the previous step and are not described in detail herein. Fresh corn ear blocks are preferably placed in the large insect breeding box, so that the primarily hatched nymphs can supplement nutrition in time. In the invention, the nymphae of the lygus lucorum is changed into adults after 5 molts for 10 days on average; during the period from nymphs to adults, the average survival rate reaches 71.84 percent.

By utilizing the method, the cultured adult can be purified for 5 generations to provide a standard test insect for the research of the lygus lucorum. The purification method is adopted for passage so as to lead the genetic background of the raised offspring to be consistent.

The method for rapid propagation of lygus lucorum provided by the invention is described in detail below with reference to examples, but they should not be construed as limiting the scope of the invention.

Example 1

Indoor artificial breeding method for lygus lucorum

(1) Collecting adult Leptodermus lucorum from host fields such as corn by using an insect catching net or an insect sucking device, and putting the caught adult into an insect rearing cage (15 x 15cm) of 180 meshes for subsequent experiments;

(2) a transparent plastic medium-sized insect-raising box (with the diameter of 10.2cm and the height of 6.5cm) is prepared, and 2 layers of water-absorbing paper are laid in the box, so that the box can be conveniently and timely replaced, and mildew generated in the box can be cleaned. Placing some bent filter paper strips (1 × 5cm) for the movement of the adelphocoris suturalis;

(3) the corn purchased is fresh fruit corn without pesticide application. Removing bracts from fresh corn ears, cutting the corn ears with corn cob into corn blocks along gaps between adjacent corn kernels by using a cutter, wherein each corn block contains 10-30 corn kernels, stripping off the incomplete corn kernels at the cut positions, and wiping off slurry flowing out of the corn kernels by using absorbent paper. The treated corn blocks are used as food and oviposition media of adult lygus lucorum;

(4) inoculating the adult lygus lucorum in the insect cage into a medium-sized insect culturing box, putting 6-8 insects into each box, wherein the ratio of male to female is nearly 1: 1.5-2, carrying out paired culturing, covering the opening of the insect culturing box with 100-mesh nylon mesh cloth, and sealing tightly with a rubber band;

(5) adult breeding is carried out at the temperature of 25 +/-1 ℃, the relative humidity of 65 +/-5 percent and the photoperiod of 16: feeding in 8 (L: D) artificial climate box (PRX-280C type intelligent artificial climate box, Ningbo sanden experiment apparatus Co., Ltd.) with corn block replacement every 3 days.

(6) Spawning: after the adult insects are mated, the female insects lay eggs after 4-5 days, and the eggs are collected once every morning at about 10 o' clock. The egg mass is mostly produced inside the seed coat at the base of the corn kernel (fig. 1). The egg mass generally comprises 4-8 eggs, at most 19 eggs, which are arranged in parallel. When the eggs are collected, the corn kernels with the egg masses are gently pulled (sheared) from the base by using tweezers or scissors and then put into a small insect-culturing box (the diameter is 3.7cm and the height is 3.3 cm). If moisture is generated in the box, the box is wiped in time so as to prevent the nymphs which are hatched initially from being stuck and dying. The egg laying period is 10-12 days, and 70-80 eggs are averagely laid by a single female in a whole life. After the female insects lay eggs for 11 days, the female insects start to die gradually, the average life of the female adults is 16 days, and the average life of the male adults is 14 days;

(7) hatching: after 5-6 days, the eggs are about to hatch, the egg period is generally 7-8 days, the average egg hatching rate reaches 81.13%, the cover of the small-sized insect box filled with the primarily hatched nymphs is opened, the small-sized insect box is transferred to a new large-sized insect box (35 x 25 x 16cm) for feeding, and in the step 2 and the step 3, fresh corn blocks are required to be placed in the large-sized insect box, so that the primarily hatched nymphs can supplement nutrition in time;

(8) molting: through observation, the nymphae of the lygus lucorum is averagely 10 days and becomes an adult after 5 molts; during the period from nymphs to adults, the average survival rate reaches 71.84 percent.

Example 2

Hatching rate and nymph survival rate of artificially fed lygus lucorum eggs

The eggs of the apolygus lucorum in (6) in example 1, which are produced in daily life, are collected and placed into small plastic boxes (diameter 3cm and height 3cm), and 1 egg is randomly placed into each plastic box, so that the number of eggs is different. The plastic boxes were placed in a climatic chamber and the hatching of the eggs was observed and recorded at 10 am each day. Recording the eggs as nymphs after hatching, transferring the nymphs to a new plastic box for single-head feeding on the same day as molting, and providing one fresh corn kernel as food. The molting and death conditions of nymphs are observed and recorded every day, the food is replaced, and the molting is timely removed by using tweezers until adults die. The experiment was repeated 30 times. Thereby evaluating the hatchability and nymph survival rate of the artificially fed lygus lucorum eggs.

At a temperature of 25 + -1 deg.C, a relative humidity of 65 + -5%, a photoperiod of 16: 8 (L: D) in a climatic chamber. Daily feeding environment, food, feeding method and other conditions were identical to those of example 1.

The test result is shown in fig. 2, the hatching rate of the lygus lucorum eggs is as high as 81.13%, the survival rate of nymphs is improved along with the increase of the age, wherein the survival rate of the nymphs is the highest at 5 ages and reaches 99.33%, the survival rate is remarkably higher than that of the nymphs at 1 age by 87.25% (Tukey test, P is 0.012), and the total survival rate of the nymphs at the phase is as high as 71.84%. Therefore, fresh corn kernels are put into the egg block box, so that the water loss of the corn kernels can be prevented, the hatching rate of eggs is improved, and food can be provided for primarily hatched nymphs. Therefore, the hatching rate and the nymph survival rate of the artificially fed lygus lucorum eggs can achieve good effects.

Example 3

Artificial breeding of adult lygus lucorum

Two ends of each adult male and female lygus lucorum which is eclosized on the same day and cultured by the method of example 1 are selected to be bred in a matched mode, the bred adults and female lygus lucorum are placed in a plastic medium-sized insect breeding box (the diameter is 10.2cm, the height is 6.5cm), and fresh corn grains are provided as food for feeding and oviposition. Changing corn kernels every day, and carefully observing the number of eggs on the corn kernels under an anatomical lens. After the adults lay eggs (the date when the eggs are found on the corn kernels for the first time), the egg laying date of the female adults, the number of the laid eggs and the death time of the female and male adults are recorded day by day. If the male worms die, supplementing the male worms with the age close to the day of the female adults for continuously feeding; if the female insect dies, the number of eggs laid by a pair of male and female adults is recorded from the death date. The experiment was repeated 15 times. Thereby evaluating the fecundity of the artificially fed lygus lucorum adults.

The test results are shown in FIG. 3, the pre-oviposition period of the female adults is (4.17 +/-0.38) d, the longest period is 11d, and the minimum period is 2 d; the egg laying duration is (11.27 +/-0.91) d, the longest is 23d, and the shortest is 5 d. The average egg laying (72.22 + -8.02) of a single female in life has a maximum of 191 grains and a minimum of 22 grains. The female grew to lay eggs (21.17 ± 2.85) in one period, with a maximum of 71 eggs and a minimum of 6 eggs (fig. 3). After the female imagoes start to lay eggs, (2.57 +/-0.28) d, (5.7 +/-0.45) d and (9.1 +/-0.65) d reach the full egg stage, peak period and terminal full egg stage respectively (figure 4). Therefore, the artificial feeding of the lygus lucorum achieves better reproduction effect, and can provide a large number of standard insect tests for screening prevention and treatment medicaments in the future.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A method for rapidly propagating lygus lucorum is characterized by comprising the following steps: (1) placing the adult lygus lucorum into a device containing fresh corncob blocks for culturing, and collecting egg blocks every day after egg laying;

(2) putting the egg blocks collected in the step (1) into a device containing fresh corn kernels for hatching to obtain nymphs;

(3) and (3) transferring the nymphs obtained in the step (2) to a device containing fresh corn ear blocks for culture, and obtaining the adult lygus lucorum after 5 molts.

2. The method of claim 1, wherein the fresh ear pieces of corn of steps (1) and (3) are derived from fresh fruit corn, grain-filled waxy corn or grain-filled corn;

3. The method of claim 1, wherein the size of the apparatus in step (1) and step (3) is larger than the size of the apparatus in step (2).

4. The method of claim 3, wherein the device in steps (1) to (3) is a gas permeable and transparent device;

and (3) paving 1-2 layers of absorbent paper at the bottom of the device.

5. The method according to claim 1, wherein the culturing of step (1) and step (3), and the incubating of step (2) comprise: the temperature is 25 +/-1 ℃, the relative humidity is 65 +/-5%, and the photoperiod is 16 hours of light and 8 hours of darkness.

6. The method of claim 1 or claim 2, wherein said removing the ears comprises removing bracts from the fresh ears, cutting the ears into corncob pieces along gaps between adjacent kernels, each piece having between 10 and 30 kernels, removing the incomplete kernels from the cut, and removing the slurry from the kernels.

7. The method of claim 6, wherein said fresh ear of corn is replaced every 3-4 days during said culturing in steps (1) and (3).

8. The method according to claim 1 or 2, wherein said fresh corn kernels are replaced every 1-2 days at said incubating of step (2).

9. The method according to claim 1, wherein the ratio of the male and female of the adult lygus lucorum in the step (1) is 1: 1.5-2.