A method for biological control of lema fructus larva by using cyrtorrhinus lividipennis

Abstract

The application relates to the technical field of biological pest control, and particularly discloses a method for biologically controlling Plodia interpunctella larvae by using Cyrtorrhinus lividipennis, which comprises the following steps: S1, collecting C. lividipennis eggs; S2, cutting the C. lividipennis eggs into 15 eggs per small piece with scissors, and cutting a total of 60 small pieces for standby; S3, placing the cut C. lividipennis egg pieces in culture dishes with filter paper, and then moving the culture dishes into an illumination incubator; S4, after the C. lividipennis eggs are hatched, introducing Plodia interpunctella larvae at a density of 15 per dish, and feeding the nymphs and adults; S5, when the Plodia interpunctella larvae drill out of the pods and form nets during the mature period of the rape, estimating the occurrence of the insect population density per mu; and S6, releasing the C. lividipennis nymphs and adults of more than 2 ages in the field at a density of C. lividipennis:Plodia interpunctella=1-3:15. In addition, the application has the advantages of short period, less time consumption, simple operation, safety, no pollution and batch culture.

Description

Technical Field

[0001] This application relates to the field of biological pest control technology, and more specifically, it relates to a method for biologically controlling the larvae of the fennel leafminer using stink bugs. Background Technology

[0002] The fennel leafminer moth, also known as the fennel moth, rapeseed moth, or horned moth, belongs to the order Lepidoptera, family Pyralidae, subfamily Pachypodiae, and genus Pachypodiae. Its main host plants include rapeseed, fennel, Chinese cabbage, and kale. The fennel leafminer moth is a devastating pest of spring rapeseed fields on the Qinghai Plateau, affecting an average of over 40% of the total rapeseed planting area annually, causing severe economic losses.

[0003] Chemical pesticides are currently an important means of controlling the fennel leafminer, but the long-term, large-scale, and irrational use of chemical pesticides has caused serious ecological pollution and human and animal safety problems. Pest control methods based on natural enemy control have the advantages of strong targeting and no environmental pollution, and natural enemy control is highly favored in the application of integrated pest management and green control systems.

[0004] The stink bug (Pentatophora spp.) belongs to the family Pentatomidae in the order Hemiptera and is widely distributed in my country. Both nymphs and adults prey on various pests belonging to the orders Lepidoptera, Coleoptera, and Diptera, with a particularly strong predatory ability against Lepidoptera, making them an important predatory natural enemy. Therefore, indoor and field stink bugs can be used to prey on the larvae of the fennel thin-winged moth for biological control. However, with the rapid increase and explosive reproduction of the fennel thin-winged moth, relying solely on the natural population of stink bugs for biological control is impossible. Therefore, artificial breeding of stink bugs is necessary to reduce the damage caused by fennel thin-winged moth larvae in spring rapeseed fields and promptly mitigate economic losses. Summary of the Invention

[0005] In order to artificially cultivate stink bugs in large quantities and reduce losses to spring rapeseed fields, this application provides a method for biologically controlling the larvae of the fennel leafminer using stink bugs.

[0006] This application provides a method for biological control of fennel leafminer larvae using stink bugs, employing the following technical solution:

[0007] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0008] S1. Collecting stink bug eggs;

[0009] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0010] S3. Place the trimmed bug egg masses into petri dishes lined with filter paper, then transfer the petri dishes into a light incubator. After 15 to 20 days, observe and record the hatching status of the bug eggs.

[0011] S4. After the eggs of the diamondback moth hatch, 2nd to 3rd instar diamondback moth larvae are introduced at a density of 15 larvae per dish to raise nymphs and adults.

[0012] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0013] S6. Release nymphs and adults of the second instar or older into the field at a density of 1 to 3:15 for *Pseudolarix amabilis* and *Pseudolarix amabilis*.

[0014] By adopting the above technical solution, the collected stink bug eggs are first cut into 15 pieces with scissors, then placed in a petri dish lined with filter paper and cultured in a light incubator until the eggs hatch. Then, diamondback moth larvae are introduced to feed the stink bug nymphs and adults. Finally, they are released into the field at a certain ratio. The whole process is short, time-saving, simple to operate, safe and pollution-free, and can achieve mass cultivation. It can quickly solve the problem of fennel thin-winged moth outbreaks, reduce the damage of fennel thin-winged moth larvae to rapeseed fields in Qinghai Plateau, and timely recover economic losses. Moreover, biological control will not damage the field environment.

[0015] Preferably, the temperature of the light incubator is 10℃~26℃, RH 50%~70%, and the photoperiod L:D = 16h:8h.

[0016] By adopting the above technical solution, experiments have shown that the hatching effect of bug eggs is optimal under these culture conditions.

[0017] Preferably, in step S6, 8 to 10 release points are evenly distributed per acre.

[0018] By adopting the above technical solution, 8 to 10 release points can be evenly distributed per acre, which can cover the entire acre, making the test data uniform and accurate, without appearing too many and thus increasing the workload of workers.

[0019] Preferably, an egg collection device is used when collecting bug eggs in step S1.

[0020] By adopting the above technical solution, a professional egg collection device can be used when collecting bug eggs, which can not only collect the required bug eggs conveniently and quickly, but also avoid damaging the bug eggs.

[0021] Preferably, the egg collection device includes a collection dish and a stirring spoon. The collection dish is lined with absorbent cotton, and a storage rack is fixedly installed on one side of the outer wall of the collection dish. The stirring spoon is placed inside the storage rack.

[0022] By adopting the above technical solution, when collecting bug eggs, one hand holds the collection dish, and the other hand uses a stirring spoon to scoop the bug eggs into the collection dish. This effectively prevents the human hand from coming into contact with the bug eggs, reducing discomfort to the human hand. In addition, the stirring spoon can be placed in the recycling rack after use, reducing the risk of loss or contamination of the stirring spoon.

[0023] In summary, this application has the following beneficial effects:

[0024] 1. This application involves first cutting the collected stink bug eggs into small pieces of 15 with scissors, then placing them in a petri dish lined with filter paper and culturing them in a light incubator until the eggs hatch. Diamondback moth larvae are then introduced to feed the stink bug nymphs and adults. Finally, the eggs are released into the field at a certain ratio. The entire process is short-cycle, time-saving, simple to operate, safe, and pollution-free. It allows for mass cultivation, quickly resolving the problem of fennel thin-winged moth outbreaks, reducing the damage to rapeseed fields in the Qinghai Plateau caused by fennel thin-winged moth larvae, and promptly recovering economic losses. Furthermore, biological control does not damage the field environment.

[0025] 2. In this application, it is preferred to hold the collection dish with one hand and use a stirring spoon with the other hand to stir the insect eggs into the collection dish when collecting insect eggs. This effectively prevents the human hand from coming into contact with the insect eggs and reduces discomfort to the human hand. In addition, the stirring spoon can be put into the recycling rack after use, reducing the risk of loss or contamination of the stirring spoon. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the egg collection device in this application.

[0027] Attached diagrams: 1. Egg collection device; 11. Collection dish; 12. Stirring spoon; 13. Soft cotton; 14. Storage rack. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the embodiments.

[0029] Example

[0030] Example 1

[0031] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0032] S1. Collecting stink bug eggs;

[0033] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0034] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 15 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is 10℃, RH 50%, and the photoperiod L:D = 16h:8h.

[0035] S4. After the eggs of the diamondback moth hatch, 2nd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0036] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0037] S6. Release nymphs and adults of the second instar or older into the field at a density of 1:15 of *Pseudolarix amabilis* and *Pseudolarix fenneli*. Eight release points are evenly distributed per acre in step S6.

[0038] In step S1, an egg collection device 1 is used to collect the eggs of the cricket. The egg collection device 1 includes a collection dish 11 and a stirring spoon 12. The collection dish 11 is lined with absorbent cotton 13, and a storage rack 14 is fixedly installed on one side of the outer wall of the collection dish 11. The stirring spoon 12 is placed inside the storage rack 14.

[0039] Example 2

[0040] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0041] S1. Collecting stink bug eggs;

[0042] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0043] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 15 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is 18℃, RH 50%, and the photoperiod L:D = 16h:8h.

[0044] S4. After the eggs of the diamondback moth hatch, 2nd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0045] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0046] S6. Release nymphs and adults of the second instar or older into the field at a density of 1:15 of *Pseudolarix amabilis* and *Pseudolarix fenneli*. Eight release points are evenly distributed per acre in step S6.

[0047] In step S1, an egg collection device 1 is used to collect the eggs of the cricket. The egg collection device 1 includes a collection dish 11 and a stirring spoon 12. The collection dish 11 is lined with absorbent cotton 13, and a storage rack 14 is fixedly installed on one side of the outer wall of the collection dish 11. The stirring spoon 12 is placed inside the storage rack 14.

[0048] Example 3

[0049] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0050] S1. Collecting stink bug eggs;

[0051] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0052] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 15 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is 26℃, RH 50%, and the photoperiod L:D = 16h:8h.

[0053] S4. After the eggs of the diamondback moth hatch, 2nd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0054] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0055] S6. Release nymphs and adults of the second instar or older into the field at a density of 1:15 of *Pseudolarix amabilis* and *Pseudolarix fenneli*. Eight release points are evenly distributed per acre in step S6.

[0056] In step S1, an egg collection device 1 is used to collect the eggs of the cricket. The egg collection device 1 includes a collection dish 11 and a stirring spoon 12. The collection dish 11 is lined with absorbent cotton 13, and a storage rack 14 is fixedly installed on one side of the outer wall of the collection dish 11. The stirring spoon 12 is placed inside the storage rack 14.

[0057] Example 4

[0058] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0059] S1. Collecting stink bug eggs;

[0060] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0061] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 20 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is 26℃, RH 70%, and the photoperiod L:D = 16h:8h.

[0062] S4. After the eggs of the diamondback moth hatch, 3rd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0063] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0064] S6. Release nymphs and adults of the second instar or older into the field at a density of 1:15 of *Pseudolarix amabilis* and *Pseudolarix fenneli*. In step S6, 10 release points are evenly distributed per acre.

[0065] In step S1, an egg collection device 1 is used to collect the eggs of the cricket. The egg collection device 1 includes a collection dish 11 and a stirring spoon 12. The collection dish 11 is lined with absorbent cotton 13, and a storage rack 14 is fixedly installed on one side of the outer wall of the collection dish 11. The stirring spoon 12 is placed inside the storage rack 14.

[0066] Example 5

[0067] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0068] S1. Collecting stink bug eggs;

[0069] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0070] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 20 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is 26℃, RH 70%, and the photoperiod L:D = 16h:8h.

[0071] S4. After the eggs of the diamondback moth hatch, 3rd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0072] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0073] S6. Release nymphs and adults of the second instar or older into the field at a density of 2:15 of *Pseudolarix amabilis* and *Pseudolarix fenneli*. In step S6, 10 release points are evenly distributed per acre.

[0074] In step S1, an egg collection device 1 is used to collect the eggs of the cricket. The egg collection device 1 includes a collection dish 11 and a stirring spoon 12. The collection dish 11 is lined with absorbent cotton 13, and a storage rack 14 is fixedly installed on one side of the outer wall of the collection dish 11. The stirring spoon 12 is placed inside the storage rack 14.

[0075] Example 6

[0076] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0077] S1. Collecting stink bug eggs;

[0078] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0079] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 20 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is 26℃, RH 70%, and the photoperiod L:D = 16h:8h.

[0080] S4. After the eggs of the diamondback moth hatch, 3rd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0081] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0082] S6. Release nymphs and adults of the second instar or older into the field at a density of 3:15 for *Pseudolarix amabilis* and *Pseudolarix fenneli*. In step S6, 10 release points are evenly distributed per acre.

[0083] In step S1, an egg collection device 1 is used to collect the eggs of the cricket. The egg collection device 1 includes a collection dish 11 and a stirring spoon 12. The collection dish 11 is lined with absorbent cotton 13, and a storage rack 14 is fixedly installed on one side of the outer wall of the collection dish 11. The stirring spoon 12 is placed inside the storage rack 14.

[0084] Comparative Example

[0085] Comparative Example 1

[0086] A method for biologically controlling the larvae of the fennel leafminer using stink bugs includes the following steps:

[0087] S1. Collecting stink bug eggs;

[0088] S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use;

[0089] S3. Place the trimmed *Impatiens balsamina* egg masses into culture dishes lined with filter paper, then transfer the culture dishes into a light incubator. After 15 days, observe and record the hatching status of the *Impatiens balsamina* eggs. The temperature of the light incubator is room temperature (25℃), RH 50%, and photoperiod L:D = 16h:8h.

[0090] S4. After the eggs of the diamondback moth hatch, 2nd instar diamondback moth larvae are introduced at a density of 15 larvae / dish to raise nymphs and adults.

[0091] S5. When rapeseed matures, after the larvae of the fennel thin-winged moth emerge from the pods and spin webs, investigate the number of larvae of the fennel thin-winged moth within 1 square meter, repeat 4 times, and estimate the insect population density per acre.

[0092] S6. Release nymphs and adults of the second instar or older into the field at a density of 1:15 of *Pseudolarix amabilis* and *Pseudolarix fenneli*. Eight release points are evenly distributed per acre in step S6.

[0093] The following is a summary of experiments on the effects of different temperature conditions on the hatching and survival abilities of the black bug and the effect of black bug density on its predation ability:

[0094] I. Effects of different temperature conditions on the hatching and survival of the volcano bug

[0095] Table 1. Effects of different temperature conditions on hatching and survival of the black bug.

[0096]

[0097] Table 1 shows that, except for the 10℃ treatment where the hatching rate of the black bug was below 80%, the hatching rates of all other conditions were above 91%. Among them, the hatching rate reached the highest of 96.67% at 26℃. This result indicates that 26℃ is a suitable condition for indoor population formation of black bugs, providing a basis for releasing them in the field to control pests.

[0098] II. The impact of bug density on its predatory ability

[0099] Different numbers of black-bellied stink bugs and larvae of the fennel leafminer were used in combination. The number of adult black-bellied stink bugs was 1, 2, and 3, respectively; the number of 2nd-3rd instar larvae of the fennel leafminer was 15 in each treatment. Each treatment was evaluated in disposable lunch boxes. Each treatment with different numbers of adult black-bellied stink bugs was replicated four times. The number of larvae preyed upon by the fennel leafminer was counted one day later.

[0100] Table 2. Effects of stink bug density on its predation ability

[0101]

[0102] Table 2 shows that the higher the release ratio of stink bugs and fennel leafminer moths, the more fennel leafminer moth larvae the stink bugs capture per day, which means the higher the mortality rate of fennel leafminer moths. This indicates that the predation effect of adult stink bugs on fennel leafminer moths is significant. In addition, it was found that adult stink bugs prey on 2-3 2-3 instar fennel leafminer moth larvae per day.

[0103] Performance testing

[0104] Four districts were surveyed, with four sites in each district. At each site, larvae were observed 20-30 cm from the tips of the rapeseed shoots and marked with red lines. The initial population of fennel borer larvae and the number of surviving fennel borer larvae after 7 days were investigated.

[0105] Test methods

[0106] Using the netting method, after the rapeseed matures and the larvae of the fennel leafminer emerge from the pods and spin a net, a bag (20*20*50 mm) is placed over the tip of the rapeseed, and adult stink bugs are caught in the bag. The bag opening is tied tightly to prevent the adult stink bugs from crawling out.

[0107] According to field surveys, the population densities of *Pterocarya fennelis* larvae in four 1-square-meter testing sites were 7, 12, 12, and 9 larvae respectively, with an average density of 10 larvae / square meter. Based on the release standard of *Pterocarya fennelis* to *Pterocarya fennelis* = 1–3:15, the number of *Pterocarya fennelis* released in this experiment ranged from 1333 to 6667 larvae / acre. A total of 4000 *Pterocarya fennelis* larvae were actually released. Ten release sites were set up, evenly distributed, meaning 400 larvae were released at each site.

[0108] Another control group was selected, and rapeseed was covered with a net to prevent adult stink bugs from entering. The bag opening was tied tightly to prevent stink bugs from preying on the insects.

[0109] Table 3 Evaluation of the predation ability of the field bug.

[0110]

[0111] As shown in Table 3, after the rapeseed in the field was bagged, the adult stink bug caused a mortality rate of more than 90% for the larvae of the fennel thin-winged moth.

[0112] In summary, under the conditions of photoperiod L:D = 16h:8h, RH 50%–70%, and temperature 26℃, diamondback moths can be reared on a large scale indoors. Adult diamondback moths prey on 2nd-3rd instar larvae of the fennel leafminer moth by 2-3 per day, resulting in a mortality rate of over 90% for the larvae. This demonstrates promising application prospects in the biological control of the fennel leafminer moth.

[0113] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for biologically controlling the larvae of the fennel leafminer using stink bugs, characterized in that, Includes the following steps: S1. When collecting eggs of the volcano bug, an egg collection device (1) is used; the egg collection device (1) includes a collection dish (11) and a stirring spoon (12). The collection dish (11) is lined with absorbent cotton (13), and a storage rack (14) is fixedly installed on one side of the outer wall of the collection dish (11). The stirring spoon (12) is placed in the storage rack (14). S2. Cut the bug eggs into 15 pieces each with scissors, and cut a total of 60 pieces for later use; S3. Place the trimmed bug egg masses into petri dishes lined with filter paper, then transfer the petri dishes into a light incubator. After 15 to 20 days, observe and record the hatching status of the bug eggs. S4. After the eggs of the diamondback moth hatch, 2nd to 3rd instar diamondback moth larvae are introduced at a density of 15 larvae per dish to raise nymphs and adults. S5. Using the netting method, during the rapeseed maturity period, after the larvae of the fennel thin-winged moth emerge from the pods and spin nets, investigate the basic number of fennel thin-winged moth larvae 20-30 cm from the last shoot of the rapeseed within 1 square meter, and mark them with red lines; cover the last shoot of the rapeseed with bags and collect adult stink bugs, and tie the bag opening tightly to prevent the adult stink bugs from crawling out. After 7 days, investigate the number of surviving fennel thin-winged moth larvae, repeat 4 times, and estimate the insect population density per acre; S6. Release nymphs and adults of the second instar or older into the field at a density of 1 to 3:15 between the nymph and the fennel leafminer. Distribute 8 to 10 release points evenly per acre, with the number of nymphs released ranging from 1,333 to 6,667 per acre. The method described is for the larvae of the fennel thin-winged moth in rapeseed fields in the Qinghai Plateau region. The adult bugs prey on 2-3 2-3 instar fennel thin-winged moth larvae per day, which can lead to a mortality rate of more than 90% for the larvae.

2. The method for biologically controlling the larvae of the fennel leafminer moth using stink bugs according to claim 1, characterized in that: The temperature of the light incubator is 10℃~26℃, RH 50%~70%, and the photoperiod L:D = 16h:8h.

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