Method for obtaining sterile male phenacoccus spongii and application of sterile male phenacoccus spongii

Abstract

The invention discloses a method for obtaining sterile male parasites of phenacoccus solenopsis and application of the method, and the method comprises the following steps: treating male parasites of phenacoccus solenopsis by adopting < 60 > Co-gamma ray irradiation to obtain the sterile male parasites of phenacoccus solenopsis; wherein the irradiation dose of the irradiation treatment is 60 + / -5 Gy. According to the method for obtaining the sterile male parasites of the phenacoccus solenopsis, male parasites of the phenacoccus solenopsis are treated through the < 60 > Co-gamma ray irradiation, sterile male adults of the phenacoccus solenopsis are obtained, the male adults obtained through the method can remarkably reduce the number and survival rate of offspring while eclosion, the service life and the mating competitive capacity of the male parasites are not affected, and the survival rate of the offspring is increased. The composition can be used for preventing and treating the phenacoccus solenopsis. After the irradiated phenacoccus solenopsis male adults are released in the field according to the proportion of the sterile male adults to the wild male adults being 9: 1, the male adults compete with the wild male adults for mating, so that the sterility rate of offspring is greatly increased, and the number of phenacoccus solenopsis population can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the field of agricultural pest control, and particularly relates to a method for obtaining sterile male hibiscus powdery mildew bugs and an application thereof. Background Art

[0002] Phenacoccus hibiscus Phenacoccus solenopsis Hemiptera ( Hemiptera ) Phenacoccidae Pseudococcidae ) Phenacoccus Phenacoccus , is a vicious invasive pest widely distributed worldwide. The insect is native to North America and first invaded China in June 2008. As of July 2024, the insect has spread to 130 counties (cities) in 15 provinces (autonomous regions and municipalities) and is listed as a national agricultural and forestry quarantine pest. At present, the insect has been distributed in all continents except Antarctica, and more than 200 host plants have been recorded.

[0003] The hibiscus mealybugs mainly cause direct damage by sucking the juice of the tender parts of plants in the form of nymphs and female adults, causing the flowers and fruits to fall off, the plants to grow slowly, and the damaged leaves to twist, shrink, and turn yellow, and eventually fall off. The honeydew secreted by the hibiscus mealybugs can induce sooty mold, which indirectly harms plants and hinders their photosynthesis. In severe cases, it can cause large-scale plant death. Because the insects are small in size and the damage is hidden, they can easily spread over long distances through human activities. Once they are introduced into cotton-growing areas and colonize, they will pose a serious threat to my country's cotton planting industry.

[0004] At present, the field control of Phenacoccus hibiscus mainly relies on chemical pesticides. However, its rapidly developing resistance and the white wax powder layer covering its body surface significantly reduce the penetration of insecticides, increasing the difficulty of control. The long-term and large-scale use of chemical pesticides not only causes serious damage to the ecological environment of farmland, but also affects the safety of agricultural products. Although the sex pheromone cluster trapping method can be used for prevention and control, this method is costly and can only trap and kill male adults. Due to the characteristics of multiple mating of this pest, the pest control effect of this control method is relatively limited. Therefore, it is of great practical significance to carry out green control research on Phenacoccus hibiscus.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The purpose of the present invention is to provide a method for obtaining sterile male hibiscus mealybugs and application thereof, which solves the problems of strong drug resistance, environmental pollution and threat to the safety of agricultural products in the existing use of chemical pesticides to control hibiscus mealybugs. By releasing sterile male hibiscus mealybugs for pest control, the control effect of curbing or eradicating the entire pest population can be achieved, and the method is pollution-free, non-resistant, highly specific and safe to humans, animals and natural enemies.

[0007] To achieve the above object, the present invention provides a method for obtaining sterile male Phenacoccus solenopsis, the method comprising: using 60 Co-γ ray irradiation to treat male pupae of Phenacoccus solenopsis to obtain sterile male Phenacoccus solenopsis; wherein, the irradiation dose of the irradiation treatment is 60 ± 5 Gy.

[0008] Preferably, the irradiation dose rate of the irradiation treatment is 80 ± 5 Gy / h.

[0009] Preferably, male and female insects are distinguished according to the morphological characteristics of the late second-instar nymphs of Phenacoccus solenopsis. Phenacoccus solenopsis is a typical sexually dimorphic insect. Female insects experience egg, first-instar nymph, second-instar nymph, third-instar nymph and emerge as female adults. Male insects experience egg, first-instar nymph, second-instar nymph, prepupa and pupa stages and emerge as male adults. The pupa stage is a unique stage of male insects. In the present invention, male and female insects can be distinguished by morphological characteristics and separately reared at the end of the second-instar nymph stage, which is convenient for irradiation treatment during the pupa stage.

[0010] More preferably, male insects are selected according to the morphological characteristics of the late second-instar nymphs of Phenacoccus solenopsis. The body shape of male insects at the end of the second-instar is close to oval, the surface wax powder is significantly thickened, and the dorsal spots are invisible.

[0011] Preferably, the male pupae of Phenacoccus solenopsis are male pupae of Phenacoccus solenopsis 1-2 days before eclosion.

[0012] More preferably, the male pupae of Phenacoccus solenopsis 1-2 days before eclosion have obvious wing buds and antennae and obvious constrictions appear at the junctions of the head, thorax and abdomen.

[0013] The second object of the present invention is to provide the application of the method for obtaining sterile male Phenacoccus solenopsis in the control of Phenacoccus solenopsis.

[0014] Preferably, the sterile male Phenacoccus solenopsis is released in the field.

[0015] Preferably, the sterile male Phenacoccus solenopsis is released in the field according to the ratio of the sterile male Phenacoccus solenopsis: wild male = 9-15:1.

[0016] More preferably, the sterile male Phenacoccus solenopsis is released in the field according to the ratio of the sterile male Phenacoccus solenopsis: wild male: normal female = 9-15:1:1.

[0017] More preferably, the sterile male Phenacoccus solenopsis is released in the field according to the ratio of the sterile male Phenacoccus solenopsis: wild male = 9:1.

[0018] More preferably, the sterile male Phenacoccus solenopsis Tinsley is released in the field according to the ratio of the sterile male Phenacoccus solenopsis Tinsley: wild male: normal female being 9:1:1.

[0019] The method for obtaining the sterile male Phenacoccus solenopsis Tinsley and its application in the present invention solve the problems of control difficulty and agricultural product safety existing in the current control of Phenacoccus solenopsis Tinsley by chemical pesticides, and have the following advantages: (1) The method for obtaining the sterile male Phenacoccus solenopsis Tinsley in the present invention uses 60 Co-γ ray irradiation to treat the male pupae of Phenacoccus solenopsis Tinsley to obtain sterile male adults of Phenacoccus solenopsis Tinsley. The male adults obtained by this method can significantly reduce the number and survival rate of offspring while not affecting the emergence, lifespan and mating competition ability of male insects, and can be used for the control of Phenacoccus solenopsis Tinsley. (2) In the method for obtaining the sterile male Phenacoccus solenopsis Tinsley in the present invention, the irradiation dose for irradiation treatment is 60 Gy, and the irradiation dose rate for irradiation treatment is 80 Gy / h. Under the irradiation under this condition, the emergence rate of male pupae is high, the malformation rate is relatively low, the survival rate of offspring is relatively low, and the mating competition ability is not affected. The obtained sterile male adults of Phenacoccus solenopsis Tinsley are released into the wild and compete with wild male adults for mates. After the sterile male insects mate with wild female insects, the egg quantity and egg hatching rate of female insects are significantly reduced, and the number of pests in the next generation is reduced. By releasing a large number of sterile male insects multiple times, the control effect of curbing or eradicating the entire pest population can be achieved. (3) In the application of the method for obtaining the sterile male Phenacoccus solenopsis Tinsley in the present invention, after releasing the above-mentioned irradiated sterile male adults of Phenacoccus solenopsis Tinsley in the field according to the ratio of sterile male: wild male being 9:1, they compete with wild male adults for mates, resulting in a significant decrease in the survival rate of offspring, and can effectively reduce the population quantity of Phenacoccus solenopsis Tinsley. (4) Compared with the chemical control method, the irradiation control method in the present invention has the advantages of no drug residue and being harmless to humans. At the same time, it avoids the impact on non-target organisms such as natural enemies of Phenacoccus solenopsis Tinsley, and does not induce pest drug resistance, and can be used effectively for a long time. Compared with the sex pheromone mass trapping method, this method significantly reduces the egg-laying amount of female adults by releasing irradiated male insects to mate with wild female insects multiple times, and solves the problem that sex pheromones only trap male adults and have insufficient control effect on pests that mate multiple times. Compared with the biological control method, the irradiation technology does not need to rely on the parasitism efficiency of natural enemy insects, and also omits the link of large-scale breeding of natural enemies. Therefore, compared with the traditional control technology, the present invention has significant advantages such as being ecologically friendly, highly specific, safe for non-target organisms, having a long-lasting control effect and being not easy to produce resistance. Description of the Drawings

[0020] Figure 1 Shows the effects of γ-ray irradiation treatments at different doses on the male insects of the F0 generation of Phenacoccus solenopsis Tinsley.

[0021] Figure 2 Effects of γ-ray irradiation at different doses on the reproductive parameters of the F0-F1 generations of Phenacoccus solenopsis Tinsley

[0022] Note: Different letters in the figure indicate significant differences as determined by Duncan's new multiple range test ( p <0.05). Specific implementation manners

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that: for those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the instruments not specified in the manufacturer, they are all conventional products that can be obtained through commercial purchase. For the raw materials and reagents not specified in the manufacturer, they are all commercially available products or can be prepared by known methods.

[0025] In the present invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of simplicity and convenience. Accordingly, the description of the numerical range or percentage range should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0026] The features mentioned in the present invention can be combined arbitrarily as long as there is no contradiction in the combination of these features. All possible combinations should be considered as the scope described in this specification. Each feature disclosed in the specification can be replaced by any alternative feature that can provide the same, equivalent, or similar purpose. Therefore, unless otherwise specified, the disclosed features are only general examples of equivalent or similar features.

[0027] Experimental example 1 Preliminary screening of the irradiation dose of male pupae of Phenacoccus solenopsis Tinsley The 60The Co-γ radiation source equipment is located at the Irradiation Center of Zhejiang Academy of Agricultural Sciences. Phenacoccus solenopsis was collected from Portulaca grandiflora in the suburbs of Xiaoshan, Hangzhou, Zhejiang Province (30°11´26˝N; 120°16´50˝E), and then continuously reared in the laboratory with potato plants (cultivar Kunyuan 9, Inner Mongolia Kunyuan Taihe Agricultural Science and Technology Co., Ltd.) as hosts to establish a stable population. The rearing conditions were: temperature 27±1°C, relative humidity 60 - 80%, and photoperiod 16 L: 8 D (light:dark = 16 h: 8 h). Male and female insects were distinguished according to the morphological characteristics of the late 2nd instar nymphs of Phenacoccus solenopsis. The body shape of male nymphs at the late 2nd instar approximated an oval shape, the wax powder on the body surface was significantly thickened, and the dorsal spots were not visible. Male nymphs at the late 2nd instar were selected for individual rearing to facilitate irradiation treatment during the pupal stage.

[0028] 1. Irradiation treatment of male pupae Male pupae with obvious wing buds and antennae and obvious constrictions at the junctions of the head, thorax, and abdomen were collected, which were male pupae 1 - 2 days before eclosion. The male pupae of Phenacoccus solenopsis were gently picked up with a brush and placed in a flat-bottomed glass tube (diameter 1.5 cm, height 8 cm), with 10 pupae placed in each glass tube. Using 60 Co-γ rays were used for irradiation treatment at a fixed dose rate point 165 cm away from the radiation source. A total of 6 irradiation dose groups were set: 20, 40, 60, 100, 150, and 200 Gy, and the corresponding irradiation times were: 0.25, 0.5, 0.75, 1.25, 1.875, and 2.5 h, respectively, with a dose rate of 80 Gy / h.

[0029] During the irradiation process, the glass tubes containing the pupae were placed in the center of the designated measurement point, facing the radiation source. The irradiation was carried out under standard atmospheric pressure (101.325 kPa), and the glass tubes were not sealed to facilitate air exchange. The irradiated pupae were transferred to plastic tubes (diameter 2.3 cm, height 9.3 cm) for individual rearing, with unirradiated male pupae as the control. Ten male pupae for each dose were used as one replicate, and a total of 9 replicates were set. The development of irradiated and unirradiated male pupae of Phenacoccus solenopsis was observed, and the mortality rate (number of dead / number of pupae), emergence rate (number of emerged / number of pupae), and wing deformity rate (number of deformed wings / number of emerged) were statistically analyzed.

[0030] As Figure 1As shown in the figure, with the increase of irradiation dose, the mortality rate of male pupae in the F0 generation gradually increases. There is no significant difference in the mortality rate of male pupae in the F0 generation after irradiation with a dose of ≤ 60 Gy compared with the control group. After irradiation with 100, 150, and 200 Gy, the mortality rate of male pupae in the F0 generation increases significantly; the emergence rate of male pupae in the F0 generation gradually decreases with the increase of irradiation dose. There is no significant difference in the emergence rate of male pupae in the F0 generation after irradiation with a dose of ≤ 60 Gy compared with the control group. After irradiation with 100, 150, and 200 Gy, the emergence rate of male pupae in the F0 generation decreases significantly; the wing deformity rate of male adults in the F0 generation increases significantly with the increase of irradiation dose. There is no significant difference in the wing deformity rate of male adults in the F0 generation after irradiation with a dose of ≤ 40 Gy compared with the control group. When the irradiation dose > 100 Gy, it causes greater harm to male insects themselves.

[0031] 2. Effects of Irradiation on the Reproduction of Phenacoccus solenopsis Tinsley in the F0 Generation Male pupae 1 - 2 days before emergence were treated with γ - rays at doses of 20, 40, 60, 100, and 150 Gy. The normally emerged male adults were separately paired with non - irradiated female adults (after treatment with 200 Gy of γ - rays, the mortality rate and wing deformity rate of male insects were relatively high, not meeting the technical requirements of irradiation sterility, so subsequent experiments were not carried out). They were reared in flat - bottomed glass tubes containing potato leaves, and the pairing of normal non - irradiated male and female adults was used as a control. Each treatment group had 15 pairs. The mating situation of male and female adults was observed, and the mating rate, pre - oviposition period of female adults, number of eggs laid per female, hatching rate of eggs, lifespan of male insects, and the proportion of female adults in the F1 generation (number of female adults / total number of adults) were statistically analyzed. Each experiment was repeated 3 times.

[0032] As Figure 2 shown, the mating rates of the F0 generation after irradiation with γ - rays at doses of 20, 40, 60, 100, and 150 Gy were 87.36%, 80.95%, 77.91%, 63.75%, and 11.80% of the control group respectively. The oviposition periods of female insects in the F0 generation were 88.10%, 73.94%, 70.96%, 48.06%, and 22.54% of the control group respectively. The number of eggs laid per female in the F0 generation was 75.12%, 60.18%, 47.99%, 26.36%, and 9.43% of the control group respectively. The hatching rates of eggs in the F1 generation were 92.26%, 86.82%, 76.65%, 44.92%, and 0.13% of the control group respectively. Compared with the control, after irradiation with a dose > 100 Gy, the lifespan of male insects in the F0 generation decreased significantly, and the sex ratio of surviving adults became more and more biased towards male adults with the increase of irradiation dose. Thus, the mating rate, oviposition period of female insects, number of eggs laid, lifespan of male insects, hatching rate of eggs in the F1 generation, and the proportion of female adults in the F0 generation all decreased significantly with the increase of irradiation dose.

[0033] Based on the effects of γ-ray irradiation at different doses on various biological parameters of the F0 and F1 generations of Phenacoccus solenopsis, it was found that irradiation treatment with 60 Gy could significantly reduce the egg production and egg hatching rate of the F1 generation while not affecting the emergence and lifespan of male insects in the F0 generation. Therefore, 60 Gy was preliminarily screened as the optimal dose for irradiation sterility.

[0034] Experimental Example 2 Verification and determination of the optimal dose for irradiation sterility of male pupae of Phenacoccus solenopsis 1. Effects on the growth, development and reproduction of the F1 generation of Phenacoccus solenopsis Male pupae of Phenacoccus solenopsis 1 - 2 days before emergence were irradiated with γ-rays at a dose of 60 Gy. After emergence, the F0 generation male insects were separately paired with normal female adults and reared in flat-bottomed glass tubes containing potato leaves. After the female insects laid eggs, the egg production and egg hatching were recorded. The hatched F1 generation nymphs were fed potato leaves, and their development was observed daily to record the developmental duration at each stage. When the F1 generation adults emerged, the emerged adults were paired with opposite-sex adults that had not been irradiated. The control group was set as: UM×UF, and the treatment groups were: IM1×UF, IF1×UM, IM1×IF1 (IM1 = male insects of the F1 generation irradiated with 60 Gy γ-rays during the pupal stage; F1 = female insects of the F1 generation irradiated with 60 Gy γ-rays during the pupal stage; UM is normal male insects; UF is normal female insects). The mating situation of male and female adults was observed, and the mating rate of the F1 generation, the pre-oviposition period, oviposition period, post-oviposition period (the time from the last egg laying to the death of the female adult) of female adults in the F1 generation, the egg production per female in the F1 generation, the hatching rate of eggs in the F2 generation, and the proportion of female adults in the F2 generation (number of female adults / total number of adults) were statistically analyzed. The development of at least 200 eggs and 60 - 80 first-instar nymphs was observed for each treatment, and the experiment was repeated 3 times.

[0035] The experimental results are shown in Table 1. The egg hatching rate of the F1 generation, the survival rates of female and male nymphs, prepupae and preadults of male insects irradiated with γ-rays at a dose of 60 Gy were all significantly reduced. These 5 biological parameters were only 76.65%, 73.18%, 74.93%, 84.60% and 60.00% of those of normal offspring, respectively. Compared with normal offspring, the egg stage, female nymph stage and preadult stage of the F1 generation were significantly prolonged after irradiation, and the lifespan of male adults in the F1 generation was significantly shortened.

[0036] Table 1 Effects of irradiating male pupae of Phenacoccus solenopsis with 60 Gy γ-rays on the growth and development of the F1 generation Note: IM0 represents male adults of the F0 generation irradiated with 60 Gy γ-rays, and UF represents normal female adults. The data in the table are mean ± standard error. Asterisks indicate significant differences by independent sample t test (* p <0.05, ** p< 0.01, *** p (< 0.001), where ns indicates no significant difference after independent sample t test.

[0037] The experimental results are shown in Table 2. After normal female insects were paired with male insects treated with an irradiation dose of 60 Gy during the pupal stage, some reproductive parameters of the F1 generation adults produced had significant differences. Among them, there were no significant differences in the mating rate of F1 generation male and female insects, the pre-oviposition period and oviposition period of F1 generation female insects compared with the control. However, there were significant differences in the post-oviposition period, fecundity of F1 generation female insects, hatching rate of F2 generation eggs and female proportion. Compared with the control group (UM×UF), mating of treated female insects with normal male insects (IF1×UM) and mating of treated female insects with treated male insects (IM1×IF1) significantly shortened the post-oviposition period of F1 generation female insects; after mating of treated male insects with normal female insects (IM1×UF), mating of treated female insects with normal male insects and mating of treated female insects with treated male insects, the fecundity of F1 generation female insects decreased significantly, being 58.99%, 66.06% and 48.17% of the control group respectively. At the same time, irradiation treatment significantly reduced the hatching rate of F2 generation eggs and the proportion of female adults. Thus, it can be seen that the population after irradiation with a 60 Gy dose of γ-rays is not only not easy to survive, but the number of female adults also decreases significantly, which is not conducive to the continuation of the population.

[0038] Table 2 Effects of irradiating male pupae of Phenacoccus solenopsis with 60 Gy dose of γ-rays on the reproduction of F1 generation Note: IM1 = F1 generation male insects irradiated with a 60 Gy dose of γ-rays during the pupal stage; IF1 = F1 generation female insects irradiated with a 60 Gy dose of γ-rays during the pupal stage; UM is normal male insects; UF is normal female insects. The data in the table are mean ± standard error. Different letters in the same row indicate significant differences tested by Duncan's new multiple range method ( p < 0.05).

[0039] 2. Effects on the growth and development of F2 generation Phenacoccus solenopsis The F1 generation male and female insects after irradiation treatment with a 60 Gy dose of γ-rays were respectively paired with normal opposite sexes at a ratio of 1:1 (control group: UM×UF; treatment groups: IM1×UF; IF1×UM; IM1×IF1; IM1 = F1 generation male insects irradiated with a 60 Gy dose of γ-rays during the pupal stage; IF1 = F1 generation female insects irradiated with a 60 Gy dose of γ-rays during the pupal stage; UM is normal male insects; UF is normal female insects), and were reared in flat-bottom glass tubes containing potato leaves. After the female insects laid eggs, the developmental duration of the eggs was recorded. The hatched F2 generation nymphs were fed potato leaves, and the development was recorded every day. The development of at least 200 eggs and 60 - 80 first-instar nymphs was observed for each treatment, with 3 replicates.

[0040] The experimental results are shown in Table 3. After normal female insects were paired with irradiated male insects, the F1 generation of insects were paired in different ways, and there were significant differences in the developmental durations and survival rates of some stages of the F2 generation of insects they produced. The female nymph stage of the F2 generation produced by the mating group of treated male insects and normal female insects (IM1×UF) was extended by 0.69 d compared with the control, and the pre-adult stage was extended by 0.61 d compared with the control. There were no significant changes in the egg stage, male nymph stage, prepupa stage and pupa stage; the female nymph stage of the F2 generation produced by the mating group of treated female insects and normal male insects (IF1×UM) was extended by 0.52 d compared with the control, and the pre-adult stage was extended by 0.64 d compared with the control. There were no significant changes in the egg stage, male nymph stage, prepupa stage and pupa stage; the female nymph stage of the F2 generation produced by the mating group of treated male insects and treated female insects (IM1×IF1) was extended by 0.62 d compared with the control, the pupa stage was extended by 0.65 d compared with the control, and the pre-adult stage was extended by 0.66 d compared with the control. There were no significant changes in the egg stage, male nymph stage and prepupa stage. Compared with the control group, the survival rates of female and male nymphs, pupae and pre-adults in the F2 generation of the treatment group were significantly reduced. This shows that the sterility effect of male Phenacoccus solenopsis caused by 60 Gy dose of γ-ray can be extended to multiple generations, has heritability, and can significantly reduce the population size of offspring.

[0041] By measuring the growth, development and reproductive parameters of the F1 and F2 generations of Phenacoccus solenopsis, the present invention found that irradiating male pupae of Phenacoccus solenopsis with 60 Gy dose of γ-ray can cause a lower survival rate of offspring while not affecting the mating rate of male and female insects in the F1 generation, significantly reducing the population size, and determining that the 60 Gy dose is indeed the optimal dose for irradiation sterility of Phenacoccus solenopsis.

[0042] Table 3 Effects of irradiating male pupae of Phenacoccus solenopsis with 60 Gy dose of γ-ray on the growth and development of the F2 generation Note: IM1 = F1 generation male insects irradiated with 60 Gy dose of γ-ray during the pupa stage; IF1 = F1 generation female insects irradiated with 60 Gy dose of γ-ray during the pupa stage; UM is normal male insects; UF is normal female insects. The data in the table are mean ± standard error. Different letters in the same row indicate significant differences tested by Duncan's new multiple range method ( p <0.05).

[0043] Experimental Example 3 Effects of γ-ray irradiation on the mating competition ability of Phenacoccus solenopsis Collect male pupae of Phenacoccus solenopsis Tinsley 1 - 2 days before eclosion and irradiate them with γ - rays at a dose of 60 Gy. Place the emerged irradiated males (IM), non - irradiated males (UM), and non - irradiated females (UF) in different combinations in an insect - rearing cage (25 cm×25 cm×25 cm) for a mating competition experiment. Set 8 treatments with ratios of 0:1:1, 1:0:1, 1:1:1, 3:1:1, 6:1:1, 9:1:1, 12:1:1, and 15:1:1. Except for the 1:0:1 treatment group which releases 5 irradiated males + 5 non - irradiated females, place 5 pairs of non - irradiated adult males and females in each insect - rearing cage, and sequentially release 0, 5, 15, 30, 45, 60, and 75 irradiated males into the corresponding ratio groups for mating until all male adults die. Transfer the females to plastic jars (diameter 8.5 cm, height 10 cm) and rear them with sprouted potato tubers. Record the egg - laying amount and egg hatching rate of females during the peak egg - laying period of 5 days for different combinations. Each treatment has 3 replicates. Calculate the mating competition index of irradiated sterile males ( C ) as follows:

[0044] In the formula, N is the number of normal male adults; S is the number of irradiated male adults; H a is the hatching rate of eggs laid by normal male and female adults mating; H o is for a certain N / S the hatching rate of eggs laid by the mixed male adults in a certain ratio and normal female adults mating; H s is the hatching rate of eggs laid by normal female adults and irradiated male adults mating.

[0045] The experimental results are shown in Table 4. The male adults of Phenacoccus solenopsis irradiated with 60 Gy of γ-ray can significantly reduce the fecundity and egg hatching rate. When the ratio of irradiated males:normal males:normal females is 9:1:1, the fecundity of females is the lowest. Compared with the situation where only normal male and female adults exist, the fecundity is reduced by 41.16%. When the ratio of irradiated males:normal males:normal females is 15:1:1, the egg hatching rate is the lowest. Compared with the situation where only normal male and female adults exist, the egg hatching rate decreases by 56.49%. The mating competition index of sterile males increases significantly with the increase of the release ratio. At the release ratios of 9:1:1, 12:1:1 and 15:1:1, the mating competition indices of sterile males are all close to 1, indicating that irradiated males have the same mating competitiveness as normal males. When the release ratio is 9:1:1, the mating competition index of sterile males reaches the peak value of 1.24. This shows that the irradiation treatment with 60 Gy of γ-ray does not affect the mating competitiveness of male adults, and they can compete with wild male adults for female adults. When released in large numbers in the field, the population quantity can be significantly reduced.

[0046] Table 4 Effects of 60 Gy γ-ray irradiation on the mating competition ability of male adults of Phenacoccus solenopsis Note: IM represents male adults irradiated with 60 Gy of γ-ray, UM represents normal male adults, and UF represents normal female adults. The data in the table are mean ± standard error. Different letters in the same column indicate significant differences tested by Duncan's new multiple range method ( p <0.05).

[0047] Experimental Example 4 Evaluation of the control effect of irradiated sterile male Phenacoccus solenopsis by cage test This experiment was carried out in the greenhouse of the experimental area of Zhejiang Academy of Agricultural Sciences, Jianqiao Sub-district, Shangcheng District, Hangzhou City, Zhejiang Province, China. The area of the greenhouse is 4 m × 10 m, and 12 nylon mesh cages (75 cm × 75 cm × 75 cm) with 120 meshes are placed. The distance between each cage is 35 cm, and they are arranged in a random order. The experiment started on February 15, 2025 and ended on March 20, 2025.

[0048] The potato variety under test was Kunyuan 9 (Inner Mongolia Kunyuan Taihe Agricultural Technology Co., Ltd., Xilingol, Inner Mongolia), and the planting density was 10 plants per cage, with a plant spacing of approximately 20 cm. The test insects were 1-day-old male Phenacoccus solenopsis Tinsley. After the male pupae were irradiated with 60 Gy of γ-rays and emerged, they were released in different proportions with non-irradiated male insects (1-day-old) and non-irradiated female insects (3-day-old), specifically including 0:1:1 (blank control), 1:0:1, 9:1:1, and 0:1:1 (drug spraying), a total of 4 release proportions. Except for the 1:0:1 treatment group that released 10 irradiated male insects + 10 non-irradiated female insects, 10 non-irradiated male and female insects were released in each cage. The number of irradiated male insects released in the 4 release proportions was 0, 10, 90, and 0 respectively. On February 21, 2025, the drug evenly sprayed using a manual sprayer was 50% acetamiprid water dispersible granule (Sichuan Runer Technology Co., Ltd., Chengdu, China), and the application concentration was 0.2 g / L. The experiment was set with 3 replicates.

[0049] On the 10th, 15th, and 20th days after the release of the insects, a systematic investigation was conducted on all plants inside the screen: the number of leaves with eggs was marked and the number of egg grains was counted. A total of 200 eggs were picked from each plant and placed on potato leaves to observe the number of unhatched egg grains, the sterility rate was calculated, the damage situation of the plants was counted, and the control effect was calculated. The specific calculation methods are as follows:

[0050] The experimental results are shown in Table 5. After 20 days of the release of Phenacoccus solenopsis Tinsley, the egg-laying amount and the hatching rate of eggs in the treatment groups were significantly lower than those in the control group. The treatment group with a ratio of sterile male insects to non-irradiated male insects of 9:1 had the lowest egg-laying amount. Compared with the control group, the egg-laying amount decreased by 56.04%; the treatment group with a ratio of sterile male insects to non-irradiated male insects of 1:0 had the lowest egg hatching rate. Compared with the control group, the egg hatching rate decreased by 57.90%; when the ratios of sterile male insects to non-irradiated male insects were 1:0 and 9:1 respectively, the sterility rates were 64.5% and 59.5% in sequence, both significantly higher than those in the control group, and there was no significant difference from the 50% acetamiprid chemical control group (55.83%). There was no significant difference in the control effect on plants between the irradiated treatment groups with ratios of sterile male insects to non-irradiated male insects of 1:0 and 9:1 and the chemical control group. The results showed that the released sterile male insects could compete with wild male insects for mates, significantly increase the egg sterility rate, effectively reduce the population quantity of Phenacoccus solenopsis Tinsley, and achieve the control effect of suppressing the population of Phenacoccus solenopsis Tinsley. The feasibility of the irradiation sterilization technology for controlling the population of Phenacoccus solenopsis Tinsley was verified.

[0051] Table 5 Evaluation of the effects after 20 days of the release of irradiated sterile male Phenacoccus solenopsis Tinsley Note: IM represents male adults irradiated with 60 Gy of γ-rays, UM represents normal male adults, and UF represents normal female adults. The data in the table are mean ± standard error. Different letters in the same column indicate significant differences tested by Duncan's new multiple range method ( p <0.05).

[0052] In summary, the present invention irradiates the male pupae of Phenacoccus solenopsis with 60 Co-γ rays to obtain sterile male adults of Phenacoccus solenopsis. When the irradiation dose of the irradiation treatment is 60 Gy, the obtained male adults of Phenacoccus solenopsis are released into the wild and compete with wild male adults for mates. After the sterile male insects mate with wild female insects, the egg quantity and egg hatching rate of the female insects are significantly reduced, reducing the number of pests in the next generation. By releasing a large number of sterile male insects multiple times, the control effect of containing or eradicating the entire pest population can be achieved.

[0053] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions of the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A method for obtaining sterile male Phenacoccus solenopsis Tinsley, characterized in that, The method includes: Adopt 60 The male pupae of Phenacoccus solenopsis Tinsley are irradiated by Co-γ rays to obtain sterile male insects of Phenacoccus solenopsis Tinsley; wherein, the irradiation dose of the irradiation treatment is 60 ± 5 Gy.

2. The method for obtaining sterile male Phenacoccus solenopsis Tinsley according to claim 1, characterized in that, The irradiation dose rate of the irradiation treatment is 80 ± 5 Gy / h.

3. The method for obtaining sterile male Phenacoccus solenopsis Tinsley according to claim 1, differentiating male and female insects according to the morphological characteristics of the late second instar nymphs of Phenacoccus solenopsis Tinsley.

4. The method for obtaining sterile male Phenacoccus solenopsis Tinsley according to claim 3, characterized in that, Selecting male insects according to the morphological characteristics of the late second instar nymphs of Phenacoccus solenopsis Tinsley. The body shape of the late second instar male insects approaches an oval shape, the surface wax powder is significantly thickened, and the dorsal spots are invisible.

5. The method for obtaining sterile male Phenacoccus solenopsis Tinsley according to claim 1, wherein, The male pupa of Phenacoccus solenopsis Tinsley is the male pupa of Phenacoccus solenopsis Tinsley 1 - 2 days before eclosion.

6. The method for obtaining sterile male Phenacoccus solenopsis Tinsley according to claim 5, characterized in that, The male pupa of Phenacoccus solenopsis Tinsley 1 - 2 days before eclosion has obvious wing buds and antennae, and obvious constrictions appear at the junctions of the head, thorax, and abdomen.

7. Application of the method for obtaining sterile male Phenacoccus solenopsis Tinsley according to any one of claims 1 - 6 in the control of Phenacoccus solenopsis Tinsley.

8. The application according to claim 7, wherein Releasing the sterile male Phenacoccus solenopsis Tinsley in the field.

9. The application according to claim 8, wherein Releasing the sterile male Phenacoccus solenopsis Tinsley in the field according to the ratio of the sterile male Phenacoccus solenopsis Tinsley to wild male insects being 9 - 15:

1.

10. The application according to claim 9, wherein Releasing the sterile male Phenacoccus solenopsis Tinsley in the field according to the ratio of the sterile male Phenacoccus solenopsis Tinsley to wild male insects being 9:1.

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