CN115428770A - Method for adjusting egg laying time of ladybug by using alternative feed - Google Patents

Abstract

The invention relates to a method for adjusting egg laying time of ladybug by using alternative feed, which is characterized in that the ladybug is alternately fed by the alternative feed and natural preys, the alternative feed is rice moth eggs, and the ladybug is primarily eclosion adult of the ladybug with horny in Japan. According to the method, rice moth eggs are used as a substitute feed to feed the ladybug, so that the manpower and material resources of large-scale production of the ladybug are reduced on the premise of ensuring the quality of natural enemies, the shelf life is prolonged, the colonization capacity of the ladybug during field release is ensured to be at a higher level, and the biological control efficiency of the ladybug product is greatly enhanced.

Description

A method of regulating the timing of ladybug egg laying using alternative feed

technical field

The invention belongs to the technical field of biological control, and in particular relates to a method for regulating the oviposition time of ladybugs by using alternative feed.

Background technique

Whitefly Bemisia tabaci belongs to Hemiptera Aleyrodidae and is a major pest worldwide. Today, apart from Antarctica, whitefly damage has occurred in more than 90 countries around the world; in my country, except for Ningxia, Qinghai, and Tibet, other provinces are distributed. Bemisia tabaci is an omnivorous pest that hosts more than 600 species of plants. Its nymphs and adults suck plant juice and secrete honeydew to induce soot, which causes leaves to turn black and affects photosynthesis. It can also spread viruses and cause various diseases. Plant diseases cause major economic losses to the world's agricultural production.

At present, chemical control is mainly used to control Bemisia tabaci, and the effective agents used include neonicotinoids, new amides, pyrethroids and so on. However, due to the irrational use of insecticides, Bemisia tabaci have developed resistance to various insecticides to varying degrees. Moderate to high levels of resistance to two neonicotinoids and moderate to high levels of resistance to α-cypermethrin were detected in both B. tabaci biotypes (types B and Q) in southeastern China.

In the face of the control problems brought about by the rapid increase of whitefly resistance to insecticides, pest biological control technologies such as "using insects to control insects" and "using bacteria to control insects" are effective means of controlling whitefly.

The knife-horned ladybug belongs to Coleoptera Coccinellidae Coccinellidae knife-horned ladybug family Serangini, is a special-feeding ladybug of whitefly pests, and can prey on whitefly whitefly, blackthorn whitefly Aleurocanthus spiniferus, citrus whitefly Dialeurodes citri and greenhouse whitefly Lice Trialeurodes vaporariorum and so on. In South China, Central China and Taiwan, the ladybug is one of the predatory natural enemies of the local dominant species of Bemisia tabaci. The control effect of the ladybug on Bemisia tabaci was excellent, and the daily predation amount of female adults and fourth-instar larvae on Bemisia tabaci eggs was as high as 723.7 and 814.1 eggs.

Serangium japonicum is an important natural enemy of whitefly pests. It is widely distributed in southern China and only in Japan abroad. Its larvae and adults can feed on different stages of whitefly. It is especially fond of eggs, has the advantages of short reproductive cycle and large egg production, and can effectively control the growth of whitefly population in a short period of time, which is of great development and utilization value.

Natural enemy ladybug is one of the important groups of predatory natural enemies, and a large number of researchers have been working on the application of natural enemy ladybug in biological control. The natural enemy ladybug can be successfully bred in the laboratory by planting host plants to reproduce prey. At present, the propagation of the ladybug mainly relies on the whitefly nymphs on the host plant, which requires a lot of human and material resources. Therefore, large-scale Production is necessary for the practical use of predatory ladybugs in enhanced biological control. Traditional feeding methods that rely on natural prey require a large number of prey and their host plants. Environmental factors such as temperature, photoperiod, and humidity also seriously affect the expansion of prey. Maintaining the continuity of the complex tertiary nutrient system is a huge challenge. The large-scale expansion of predatory ladybugs requires a lot of manpower and material resources. The high cost of production has always been the key bottleneck that prevents predatory ladybugs from being widely used in agricultural and forestry production. Therefore, the large-scale expansion of natural enemies dominated by low-cost feed is a necessary condition for the promotion and application of biological control. The market urgently needs new technologies for high-efficiency and environmentally friendly biological control to solve the problem of sustainable control of the resistant pest Bemisia tabaci. The production of green food provides technical support.

At present, in the process of large-scale expansion of natural enemies, the amount of eggs laid is an important indicator. When predatory ladybugs eat alternative feeds, the egg production will be significantly reduced.

Ding Xueling et al. studied the effects of two alternative prey species on the growth, development and fecundity of S. japonica. Using the eggs of Bemisia tabaci as a control, they studied the effects of eggs of Mediterranean mealworm and rice moth on the growth, development and reproduction of S. japonica. force influence. The results showed that the nutrition at the larval and adult stages of ladybugs had a significant impact on the oviposition ability of adults: the larval stage was fed with the eggs of M. medidae, and the eggs of M. medinalis and med. 64.45 grains and 53.82 grains respectively); the larval stage was fed with eggs of Mediterranean mealworm, and the adult stage was fed with whitefly eggs, and the egg production (539.10 grains) was not significantly different from that of the control group; Feed the eggs of Mediterranean mealworm and rice moth respectively at the adult stage, and the egg production was significantly reduced (59.30 and 71.38 eggs, respectively). Therefore, the eggs of Mediterranean mealworm can be used as an alternative prey for ladybug larval rearing.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art, and provide a method for regulating the oviposition time of ladybugs by using alternative feeds, using rice moth eggs as substitute feed, and alternately using rice moth eggs and natural prey in the adult stage Feeding, the egg production of ladybugs was not significantly different from that of the control group, reducing the resource consumption of the natural prey Bemisia tabaci and prolonging the shelf life of ladybugs.

For solving above technical problem, the technical scheme that the present invention takes is:

The invention discloses a method for regulating the egg-laying time of ladybugs by using alternative feeds. The ladybugs are alternately fed with alternative feeds and natural prey. The alternative feeds are rice moth eggs, and the ladybugs are the first eclosion adults of the ladybug japonica.

Preferably, the fledgling adults are fed from natural prey.

Preferably, the ladybugs are fed with rice moth eggs for one cycle and then switched to natural prey.

Preferably, one cycle is less than or equal to 50 days.

Preferably, one cycle is 30-50 days.

Preferably, the rice moth eggs are fresh rice moth eggs inactivated with ultraviolet lamps.

Preferably, the natural prey is Bemisia tabaci nymphs.

Preferably, the breeding temperature of ladybugs is 20°C-30°C.

Preferably, the feeding photoperiod L:D of ladybugs is 12-14:10-12.

Due to the adoption of the above technical solutions, the present invention has the following advantages compared with the prior art:

1, the present invention has confirmed the feasibility of rice moth ovum as the alternative feed of ladybug, solves the technical bottleneck problem of the large-scale breeding of ladybug;

2. The present invention has analyzed and researched the influence of feeding rice moth eggs on the ladybug's oviposition and damage control ability at the adult stage, and proposed for the first time to replace low-temperature storage with alternative feed to prolong the shelf life, and simultaneously solve the problems of transportation conditions and food materials;

3. The present invention ensures that the colonization ability of ladybugs is at a relatively high level when they are released in the field, and greatly enhances the biological control efficiency of ladybug products.

Description of drawings

Fig. 1 is an analysis diagram of the egg production of the lady beetle female larvae feeding on Bemisia tabaci after feeding rice moth eggs for different periods of time;

Fig. 2 is an analysis chart of the average daily egg production of the ladybug female bemiphora feeding on Bemisia tabaci after feeding rice moth eggs at different times;

Fig. 3 is an analysis chart of the survival rate of the ladybugs from one generation to the next after being fed with rice moth eggs for different periods of time;

Fig. 4 is an analysis diagram of the developmental period of the first generation of bemisia tabaci after being fed with rice moth eggs for different periods of time;

Fig. 5 is the daily predation analysis figure of the fourth instar larvae of the first generation fourth instar larva of bemisia tabaci to the fourth instar larva of bemisia tabaci after the rice moth ovum is fed differently;

Fig. 6 is the figure that adult beetle japonica gets food rice moth ovum;

Fig. 7 is a diagram showing that the adult beetle beetle feeds on the larvae of Bemisia tabaci.

detailed description

In order to make the technical solutions and beneficial effects of the present invention more obvious and easy to understand, the following will describe in detail by referring to the accompanying drawings and listing specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

As natural enemy insects are living products, prolonging the shelf life of natural enemies is an important means to deal with overproduction and off-season demand. The main way to extend the shelf life of ladybugs is low temperature storage. However, the applicant found in the study that long-term low-temperature storage led to a significant decline in the survival rate and egg laying of ladybugs, seriously reducing the application effect of natural enemy products. After the ladybug eggs were stored at low temperature, the egg hatching rate decreased, and at the same time, the eclosion rate, egg production and offspring hatching rate decreased significantly. Therefore, long-term low-temperature storage is obviously not the best way to prolong the shelf life of natural enemy insects.

In the research, the applicant innovatively found that the total egg production and the biological characteristics of offspring were not significantly different from those of the control group when the alternative feed - rice moth eggs and natural prey were alternately fed to ladybugs. Therefore, compared with low temperature storage to prolong the shelf life, the method of feeding rice moth eggs has a longer delay and has less impact on the biological characteristics related to the quality of the natural enemy ladybug. Alternate feeding of rice moth eggs and Bemisia tabaci brought a new idea to the large-scale propagation of ladybug.

The invention discloses a method for regulating the oviposition time of ladybugs by using alternative feeds. The ladybugs are alternately fed with alternative feeds and natural prey, wherein the alternative feeds are rice moth eggs, and the ladybugs are first eclosion adults of the ladybug japonica.

In certain embodiments, the fledgling adults are fed from natural prey.

In certain embodiments, the ladybugs are fed with rice moth eggs for one cycle and then switched to natural prey.

In some embodiments, one cycle is less than or equal to 50 days, preferably, one cycle is 30-50 days, more specifically, it can be 30 days, 40 days, or 50 days.

In certain embodiments, the rice moth eggs are fresh rice moth eggs that are inactivated with ultraviolet light.

In certain embodiments, the natural prey is Bemisia tabaci nymphs.

In some embodiments, the breeding temperature of ladybugs is 20°C-30°C, preferably 22-28°C, more preferably 26±2°C.

In some embodiments, the feeding photoperiod L:D of ladybugs is 12-14:10-12, preferably 13-14:10-11, more preferably 14:10.

If no specific technique or condition is indicated in the examples, it is usually carried out according to the conventional technique or condition described in the literature in this field, or according to the product specification and the conditions suggested by the manufacturer. The materials used, unless otherwise specified, are conventional products that can be purchased through formal commercial channels.

The research material used in the embodiment is as follows:

Test plants: Cotton Gossypium spp.: the variety is Lumianyan 32.

Insects to be tested:

Bemisia tabaci: a laboratory population preserved with cotton seedlings as hosts.

Japonica japonica: a laboratory population subcultured on cotton seedlings with Bemisia tabaci nymphs as food.

Rice moth eggs: purchased from Guangzhou Yuefeng Biological Control Technology Co., Ltd., referring to the method of Yang Liwen et al. (2014) to artificially raise rice moths, specifically: indoors (temperature: 25°C-28°C, humidity: 60%-80% ), using corn flour: soybean flour: wheat bran in a weight ratio of 7:2:1 for artificial feeding, and the larvae were reared in an insect rearing box of 455 mm×325 mm×40 mm. After the larvae emerged, they were collected Adults were placed in gauze pouches of 100 mm × 50 mm to lay their eggs, and fresh eggs were collected every day and then inactivated with ultraviolet light for testing.

Conditions in the insect culture room: temperature 26±2°C, photoperiod L:D: 14:10.

Instrument consumables:

Intelligent artificial climate incubator (RXZ-436E-LED): Ningbo Jiangnan Instrument Factory, insect stereoscope (Stemi508): Zeiss.

Insect cage: 60cm×60cm×60cm, petri dish: φ=60mm, h=10mm, finger tube: φ=8mm, h=30mm, absorbent cotton, soft brush, tweezers, scissors, tray, etc.

Data processing: Excel 2010 and SPSS 22.0 software were used for data processing and analysis.

Example 1

The newly hatched larvae of Ladybug were collected and fed to the nymphs of Bemisia tabaci to obtain the newly emerged adults. The male and female adults were matched and placed in a single pair in a petri dish, and fresh inactivated rice moth eggs were added to the petri dish every day, and after 30 days Change cotton leaves with bemisia nymphs daily instead. The survival and oviposition of ladybugs were recorded every day, and this group of treatments was repeated 10 times.

Collect the egg masses of the ladybug females in this treatment group at the peak of oviposition, check the hatching of the ladybug eggs twice a day, and transfer the newly hatched larvae to the finger tube with a soft brush after the eggs hatch. And seal it with absorbent cotton balls, and replace the leaves with Bemisia tabaci nymphs once a day until the larvae pupate. Observe and record the egg hatching rate, the developmental period of the generation and the survival rate of the first generation of the ladybug larvae that feed on the eggs of the rice moth, and observe 30 eggs in this group, with 3 repetitions.

Put the clean cotton seedlings into the insect cage and insert the whitefly adults for 24 hours, then suck away the whitefly adults, wait for the eggs laid by the whitefly adults on the cotton leaves to hatch into whitefly nymphs, and the whitefly nymphs develop to 4 years old. Feed the first-generation larvae of this group to bemisia tabaci nymphs to the 4th instar, put a single larva into a petri dish and starve for 12 hours, then put it into cotton leaves containing 100 4th instar nymphs of bemisia tabaci, and check each dish after 24 hours The remaining number of Bemisia tabaci nymphs. This group of treatments was set to repeat 10 times.

Example 2

The newly hatched larvae of Ladybug were collected and fed to the nymphs of Bemisia tabaci to obtain the newly emerged adults. The adults were matched with each other and placed in a single pair in a petri dish. Fresh inactivated rice moth eggs were added to the petri dish every day. After 40 days Change cotton leaves with bemisia nymphs daily instead. The survival and oviposition of ladybugs were recorded every day, and this group of treatments was repeated 10 times.

Collect the egg masses of the ladybug females in this treatment group at the peak of oviposition, check the hatching of the ladybug eggs twice a day, and transfer the newly hatched larvae to the finger tube with a soft brush after the eggs hatch. And seal it with absorbent cotton balls, and replace the leaves with Bemisia tabaci nymphs once a day until the larvae pupate. Observe and record the egg hatching rate, the developmental period of the generation and the survival rate of the first generation of the ladybug larvae that feed on the eggs of the rice moth, and observe 30 eggs in this group, with 3 repetitions.

Put the clean cotton seedlings into the insect cage and insert the whitefly adults for 24 hours, then suck away the whitefly adults, wait for the eggs laid by the whitefly adults on the cotton leaves to hatch into whitefly nymphs, and the whitefly nymphs develop to 4 years old. Feed the first-generation larvae of this group to bemisia tabaci nymphs to the 4th instar, put a single larva into a petri dish and starve for 12 hours, then put it into cotton leaves containing 100 4th instar nymphs of bemisia tabaci, and check each dish after 24 hours The remaining number of Bemisia tabaci nymphs. This group of treatments was set to repeat 10 times.

Example 3

The newly hatched larvae of Ladybug were collected and fed to the nymphs of Bemisia tabaci to obtain the newly emerged adults. The adults were matched with each other and placed in a single pair in a petri dish. Fresh inactivated rice moth eggs were added to the petri dish every day. After 50 days Change cotton leaves with bemisia nymphs daily instead. The survival and oviposition of ladybugs were recorded every day, and this group of treatments was repeated 10 times.

Collect the egg masses of the ladybug females in this treatment group at the peak of oviposition, check the hatching of the ladybug eggs twice a day, and transfer the newly hatched larvae to the finger tube with a soft brush after the eggs hatch. And seal it with absorbent cotton balls, and replace the leaves with Bemisia tabaci nymphs once a day until the larvae pupate. Observe and record the egg hatching rate, the developmental period of the generation and the survival rate of the first generation of the ladybug larvae that feed on the eggs of the rice moth, and observe 30 eggs in this group, with 3 repetitions.

Put the clean cotton seedlings into the insect cage and insert the whitefly adults for 24 hours, then suck away the whitefly adults, wait for the eggs laid by the whitefly adults on the cotton leaves to hatch into whitefly nymphs, and the whitefly nymphs develop to 4 years old. Feed the first-generation larvae of this group to bemisia tabaci nymphs to the 4th instar, put a single larva into a petri dish and starve for 12 hours, then put it into cotton leaves containing 100 4th instar nymphs of bemisia tabaci, and check each dish after 24 hours The remaining number of Bemisia tabaci nymphs. This group of treatments was set to repeat 10 times.

Example 4

The newly hatched larvae of Ladybug were collected and fed to the nymphs of Bemisia tabaci to obtain the newly emerged adults. The adults were matched with each other and placed in a single pair in a petri dish. Fresh inactivated rice moth eggs were added to the petri dish every day. After 60 days Change cotton leaves with bemisia nymphs daily instead. The survival and oviposition of ladybugs were recorded every day, and this group of treatments was repeated 10 times.

Collect the egg masses of the ladybug females in this treatment group at the peak of oviposition, check the hatching of the ladybug eggs twice a day, and transfer the newly hatched larvae to the finger tube with a soft brush after the eggs hatch. And seal it with absorbent cotton balls, and replace the leaves with Bemisia tabaci nymphs once a day until the larvae pupate. Observe and record the egg hatching rate, the developmental period of the generation and the survival rate of the first generation of the ladybug larvae that feed on the eggs of the rice moth, and observe 30 eggs in this group, with 3 repetitions.

Put the clean cotton seedlings into the insect cage and insert the whitefly adults for 24 hours, then suck away the whitefly adults, wait for the eggs laid by the whitefly adults on the cotton leaves to hatch into whitefly nymphs, and the whitefly nymphs develop to 4 years old. Feed the first-generation larvae of this group to bemisia tabaci nymphs to the 4th instar, put a single larva into a petri dish and starve for 12 hours, then put it into cotton leaves containing 100 4th instar nymphs of bemisia tabaci, and check each dish after 24 hours The remaining number of Bemisia tabaci nymphs. This group of treatments was set to repeat 10 times.

Control (CK)

The newly hatched larvae of Ladybug were collected and fed to the nymphs of Bemisia tabaci to obtain the first eclosion adults. The adults were matched with each other and placed in a single pair in a petri dish. Cotton leaves with nymphs of Bemisia tabaci were added to the petri dish every day. The survival and oviposition of ladybugs were recorded every day, and this group of treatments was repeated 10 times.

Collect the egg masses of the ladybug females in this treatment group at the peak of oviposition, check the hatching of the ladybug eggs twice a day, and transfer the newly hatched larvae to the finger tube with a soft brush after the eggs hatch. And seal it with absorbent cotton balls, and replace the leaves with Bemisia tabaci nymphs once a day until the larvae pupate. Observe and record the egg hatching rate, the developmental period of the generation and the survival rate of the first generation of the ladybug larvae that feed on the eggs of the rice moth, and observe 30 eggs in this group, with 3 repetitions.

Put the clean cotton seedlings into the insect cage and insert the whitefly adults for 24 hours, then suck away the whitefly adults, wait for the eggs laid by the whitefly adults on the cotton leaves to hatch into whitefly nymphs, and the whitefly nymphs develop to 4 years old. Feed the first-generation larvae of this group to bemisia tabaci nymphs to the 4th instar, put a single larva into a petri dish and starve for 12 hours, then put it into cotton leaves containing 100 4th instar nymphs of bemisia tabaci, and check each dish after 24 hours The remaining number of Bemisia tabaci nymphs. This group of treatments was set to repeat 10 times.

Result analysis

1. The effect of alternate feeding of rice moth eggs and whitefly on the egg production of ladybug

See attached figure 1 for the amount of eggs laid by female beetle beetles fed with rice moth eggs at different times and then fed with whitefly nymphs (the bar graph in the figure is the average value, the error bar is the standard error, and the different letters above represent 0.05 Significantly different levels (Tukey's method)). The time when the ladybug females feed on rice moth eggs before changing to bemisia tabaci has a significant effect on the egg production of ladybugs (F _4,45 =5.45, P=0.001). The egg yields of the female bemibugs fed with rice moth eggs for 30 days, 40 days and 50 days and then fed with Bemisia tabaci were 919.89, 945.20 and 893.60 eggs respectively, which was not significantly different from that of the control group (929.82 eggs) Sexual differences; 60 days after feeding rice moth eggs, the number of eggs laid by females of A. tabaci nymphs was 811.20, which was significantly lower than that of the control group.

See Figure 2 for the daily average egg production of the female bemiphora bemis who were fed rice moth eggs for different periods of time and then changed to bemisia tabaci. Feed the eggs of the rice moth for 30 days, 40 days, 50 days and 60 days, and then switch to feeding the whitefly nymphs. The peak daily egg production can reach the level of the control group, and then the daily egg production slowly decreases until death.

The results showed that the egg production of bemisia tabaci nymphs could be rapidly increased after the females of the ladybug were fed with rice moth eggs, and the feeding time of females with rice moth eggs should not exceed 50 days, otherwise the total egg production would decrease. Decreased significantly.

2. Effects of alternate feeding of rice moth eggs and whitefly on the development, survival and predation ability of the first generation of ladybug beetle

See Figure 3 for the survival rate of the beetlebug larvae that were fed rice moth eggs for different periods of time and then fed with bemisia tabaci nymphs (the bar graph in the figure is the average value, the error bar is the standard error, and different letters on the bar graph indicate Significantly different at the 0.05 level (Tukey's method)). The time that the ladybug females feed on rice moth eggs before switching to bemisia tabaci has a significant effect on the survival rate of offspring (F _4,10 =6.29, P=0.009). The survival rates of the ladybugs fed with rice moth eggs for 30 days, 40 days and 50 days and then fed with whitefly nymphs were 82.22%, 81.11% and 77.78%, respectively, which were not significantly different from the control group's survival rate of 85.56%. The difference; the survival rate of the ladybugs who were fed rice moth eggs for 60 days and then fed Bemisia tabaci nymphs was 68.89%, which was significantly lower than that of the control group, but it was not significantly different from that of the group fed rice moth eggs for 50 days. difference.

See attached Figure 4 for the timing of female beetle beetle feeding on rice moth eggs before changing to bemisia tabaci and the developmental period of the first generation (the bar graph in the figure is the average value, and the error bar is the standard error. Different letters indicate significant differences at the 0.05 level (Tukey’s method)), the effect of the time when the ladybug females feed on rice moth eggs before changing to bemisia tabaci is the difference between the fourth instar larvae of the second generation and the fourth instar nymphs of bemisia tabaci The amount of predation is shown in Figure 5 (the bar graph in the figure is the mean value, the error bars are the standard error, and different letters on the bar graph indicate a significant difference at the 0.05 level (Tukey method)). The timing of feeding on the eggs of the rice moth before changing to bemisia tabaci females had no significant effect on the developmental duration of the offspring generation and the predation amount of the fourth instar larvae on the fourth instar nymphs of bemisia tabaci (F _4,10 =1.22, P=0.363; F _4,45 =2.21, P=0.929). The developmental duration of the first generation of offspring fed with rice moth eggs for 30 days, 40 days, 50 days and 60 days and then fed with whitefly nymphs was 17.46 days, 17.50 days, 17.54 days and 17.39 days, which was different from that of the control group. There was no significant difference at 17.37 days; the fourth-instar larvae of the offspring who fed rice moth eggs for 30 days, 40 days, 50 days and 60 days and then changed to bemisia tabaci nymphs predated 59.10, 59.10, There was no significant difference between 61.20, 60.20 and 60.70, and 59.10 predation amount of the fourth instar larvae of the control group on the fourth instar nymphs of Bemisia tabaci.

The results showed that the time of feeding the eggs of O. tabaci before Ladybug switched to feeding Bemisia tabaci had no significant effect on the developmental duration of offspring and the predation ability of Bemisia tabaci. On the 60th day, the offspring survival rate decreased significantly.

To sum up, the normal oviposition level can be recovered within 50 days after the ladybug was fed rice moth eggs and changed to bemisia tabaci nymphs. Generation survival and predation ability were not significantly affected. These results suggest that feeding rice moth eggs can be used as a means to prolong the shelf life of A. chinensis, greatly reducing the human and material resources required for daily feeding of B. tabaci nymphs.

In the large-scale multiplication and application system of ladybugs with alternate feed and natural prey, feeding rice moth eggs not only reduces the resource consumption of the natural prey Bemisia tabaci and prolongs the shelf life of ladybugs, but also can play other important roles. First, in the process of large-scale production of natural enemies, a large number of natural enemies are produced every day, and the ladybugs of various ages are uneven, so it cannot be guaranteed that the natural enemies have high colonization ability when they are released in the field. Feeding rice moth eggs prolongs the early oviposition period and reduces the amount of eggs laid by ladybugs until they are released in the field. After the ladybugs feed on natural prey, a large number of eggs are restored on plants damaged by whiteflies, which greatly improves the stability of ladybugs. breeding level. Second, during the transportation of ladybugs, feeding rice moth eggs is easier than feeding bemisia tabaci nymphs, and rice moth eggs are easier to carry and add. Adding rice moth eggs instead of whitefly nymphs in the transport box or release box can prevent ladybugs from starting to lay eggs in large numbers in the box, avoid the self-mutilation behavior of adults feeding on ladybug eggs, and also ensure the colonization of ladybugs before release ability.

To sum up, using rice moth eggs as an alternative feed to feed ladybugs can reduce the human and material resources of large-scale production of ladybugs on the premise of ensuring the quality of natural enemies, prolong the shelf life, and ensure the release of ladybugs in the field When the colonization ability is at a high level, the biological control efficiency of ladybug products is greatly enhanced.

It should be understood that the above embodiments are exemplary and not intended to cover all possible implementations covered by the claims. Various modifications and changes can also be made on the basis of the above embodiments without departing from the scope of the present disclosure. Likewise, various technical features of the above embodiments can also be combined arbitrarily to form other embodiments of the present invention that may not be explicitly described. Therefore, the above-mentioned embodiments only express several implementation modes of the present invention, and do not limit the protection scope of the patent of the present invention.

Claims (9)

1. a method utilizing substitute feed to regulate ladybug oviposition time, is characterized in that: feed ladybug alternately with substitute feed and natural prey, described substitute feed is rice moth ovum, and described ladybug is Japanese sword horn ladybug The first emergence of insects into adults. 2. The method for regulating ladybug oviposition time by using alternative feed according to claim 1, characterized in that: said first eclosion adults are fed by natural prey. 3. The method for regulating the oviposition time of ladybugs by using alternative feed according to claim 1, characterized in that: the ladybugs are fed with rice moth eggs for one cycle and then fed with natural prey. 4. The method according to claim 1, characterized in that: said one cycle is less than or equal to 50 days. 5. The method according to claim 4, characterized in that: said cycle is 30-50 days. 6. The method for regulating the oviposition time of ladybugs by using alternative feed according to claim 1, characterized in that: the fresh rice moth eggs are inactivated by ultraviolet lamps. 7. The method according to claim 1, characterized in that: said natural prey is Bemisia tabaci nymphs. 8. The method for adjusting the oviposition time of ladybugs by using alternative feed according to claim 1, characterized in that: the breeding temperature of the ladybugs is 20°C-30°C. 9. The method for regulating ladybug oviposition time according to claim 1, characterized in that: the feeding photoperiod L:D of said ladybug is 12-14:10-12.

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