Rapid sex identification method for propylaea japonica adults

Abstract

The invention discloses a rapid sex identification method for propylaea japonica adults, and relates to the technical field of insect sex identification. Collecting adult propylaea japonica; if triangular black spots or hourglass-shaped black spots exist in the middle of the forehead of the head of the adult, the adult is female; if the middle part of the forehead of the head of the adult has no triangular black spot and is yellow or milky copper bell-shaped, the adult is male; the propylaea japonica adults are adults within the third day to the thirtieth day of eclosion, the elytra color spots are in a turtle pattern shape, and the forehead of the head is yellow or milky white. According to the method disclosed by the invention, the cost is hardly needed, the operation is very simple, the sex of the propylaea japonica adults can be accurately identified under the condition of hardly damaging the propylaea japonica adults, and related researchers can completely grasp the sex of the propylaea japonica adults only by being slightly familiar with the forehead morphological characteristics of the adults.

Description

Technical Field

[0001] The invention relates to the technical field of insect sex identification, and in particular to a method for rapid sex identification of Propylaea adults. Background Art

[0002] Propylea japonica belongs to the Coccinellidae family of the order Coleoptera and is widely distributed in China, Japan, Russia and other countries. Both its adults and larvae can prey on a variety of Hemipteran pests including aphids, leafhoppers, whiteflies, planthoppers, scale insects, as well as eggs and young larvae of Lepidoptera, Coleoptera, Acarina and other pests. It is a dominant predatory natural enemy with a large population in agricultural and forestry ecosystems. Because Propylea japonica has the characteristics of short reproductive period, large egg-laying amount, large prey volume, long adult lifespan, strong heat resistance and drug resistance, it has become one of the important natural enemy insect groups in pest biological control.

[0003] As the concepts of green development, ecological protection, and healthy living have become more popular, the "weapons" used by humans to fight pests have long since shifted from highly toxic and highly residual chemical pesticides to green and pollution-free biological control methods, and a "war" without the smoke of gunpowder has quietly begun. In this process, green control integrated technology, especially comprehensive control technology based on biological control, plays a vital role in ensuring the output and quality safety of important agricultural products such as grain, vegetables, and fruits. As an important biological control natural enemy insect, more and more attention has been paid to the theoretical and applied research of the protoceratops at home and abroad. On this basis, a series of indoor large-scale breeding methods for protoceratops have also been formed, which has greatly promoted the industrialization development of the protoceratops.

[0004] The morphological characteristics of eggs, larvae, pupae, and adults of Propylae have been described in detail at home and abroad, and the structure of the female and male internal reproductive systems and the process of egg cell generation have been studied in depth, providing an important theoretical basis for the artificial breeding of Propylae. However, to date, the sex identification of Propylae adults is still mainly distinguished by dissecting the abdomen of the adult and observing its internal reproductive organs under a microscope. Although this method is highly accurate, it requires killing the insect body, the operation is also very complicated, and the operator's technical requirements are high. Due to this limitation, the research on genetic breeding and variety improvement of natural enemy insects of the Coccinellae family, including Propylae, has developed slowly: whether it is scientific research or commercial breeding, Propylae can only be collected from the wild and then propagated indoors, and the quality of the insect source cannot be guaranteed. Exploring this non-destructive sex identification method for Propylae adults is not only beneficial to traditional ecological experiments and population dynamics research, but also can lay the foundation for genetic improvement and stress resistance breeding of Propylae.

[0005] Sexual dimorphism is a phenomenon in which mature males and females of the same species differ significantly in size, shape, color, and structure, in addition to their internal and external reproductive organs. It is widely distributed in the biological world. The sexual dimorphism phenomenon of insects such as mosquitoes, mealybugs, beetles, crickets, butterflies, and cicadas has been studied in depth. Sexual dimorphism is also an important basis for determining the sex of organisms. However, to date, there has been no research on the sexual dimorphism of Propylaea. Most morphological characteristics such as size, color, and color spot type are unstable characteristics. In addition, human observation and description are subjective, which greatly limits the rapid and non-destructive identification of the sex of adult Propylaea. Summary of the invention

[0006] In order to overcome the problem in the background technology that sex identification of Propylaea adult requires dissection of external genitalia, resulting in insect death and inability to conduct subsequent scientific research, the present invention provides a method for rapid sex identification of Propylaea adult.

[0007] To achieve the above object, the present invention proposes the following technical solutions:

[0008] A method for rapid sex identification of Propylaea adults comprises the following steps:

[0009] Collecting Propylaea adults:

[0010] If the adult has a triangular black spot or an hourglass-shaped black spot in the middle of the forehead, it is a female;

[0011] If the adult has no triangular black spot in the middle of the forehead and appears yellow or milky white copper bell-shaped, it is a male.

[0012] The described Propylaea adults are adults within the 3rd to 30th day of emergence.

[0013] The adult Propylaea has a tortoise-like color spot on its elytra and a yellow or milky white forehead.

[0014] The beneficial effects of the present invention are:

[0015] The method of the present invention is simple, rapid, reliable, and conducive to popularization and application. The traditional sex identification technology of the adult protocera is mainly distinguished by dissecting the reproductive organs under a microscope. Although this method has high accuracy, it needs to kill the insect body and the operation is very complicated. The present invention can distinguish the sex of the adult by only comparing whether there is a black spot in the middle of the forehead of the adult head. In addition, when the protocera is touched and feels dangerous, its insect body quickly curls up, and it is not easy to distinguish the sex of the insect body through the external genitalia. The sex identification method of the protocera described in the present invention is simple and easy to operate, and the time used is shortened by more than 20 times compared with the traditional sex identification technology, and the accuracy rate can reach 100%. The sex can be quickly identified by this method, and the sex of the adult protocera can be accurately identified without almost damaging the insect body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a front view of an adult Propylaea.

[0017] Figure 2 This is a ventral view of an adult Propylaea.

[0018] Figure 3 It is the end of the abdomen of the adult Propylaea.

[0019] Figure 4 It is the internal reproductive organ of the adult Propylaea.

[0020] Figure 5 It provides non-destructive and rapid identification characteristics of the sex of adult Propylaea.

[0021] In the figure: 11 is a front view of a female adult toyla beetle, 12 is a front view of a male adult toyla beetle, 21 is a ventral view of a female adult toyla beetle, 22 is a ventral view of a male adult toyla beetle, 31 is the end of the abdomen of a female adult toyla beetle, 32 is the end of the abdomen of a male adult toyla beetle, 41 is the ovary of a female adult toyla beetle, 42 is the testis of a male adult toyla beetle, 51 has a triangular black spot on the forehead of the head of a female adult toyla beetle, 52 has a triangular black spot on the forehead of the head of a female adult toyla beetle, 53 has a triangular black spot on the forehead of the head of a female adult toyla beetle connected to the pronotum and hourglass-shaped, 54 has no triangular black spot in the middle of the forehead of the head of a male adult toyla beetle, and appears in a yellow or milky white copper bell shape. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0023] The following examples are provided to further illustrate the present invention, rather than to limit the present invention.

[0024] Embodiment 1: indoor rearing Propylaea adult sex rapid identification

[0025] 1. Test insect source: In May 2022, the adult protocera were collected from the cotton fields of the East Field Experimental Base of the Cotton Research Institute of the Chinese Academy of Agricultural Sciences, and brought back to the laboratory to be reared with pea aphids, of which the pea aphids were reared with broad bean seedlings. After the protocera had reproduced 4 to 5 generations indoors, 600 protocera pupae were collected. The rearing conditions were a photoperiod of 16L:8D, a temperature of 23℃-27℃, and an ambient humidity of 60%-80%.

[0026] 2. Rapid identification of adult sex: Divide the pupae into 3 groups, 200 in each group, and place them in 3 emergence cages. After the adults emerge, observe the morphological characteristics of their foreheads one by one under a stereoscope to determine their sex and make statistical analysis. If the forehead of the adult head is yellow or milky white, with a black spot in the middle, in a triangular shape (Figure 51, 51), or the top of the black spot is connected to the pronotum, resembling an hourglass shape (Figure 53), it is determined to be female; if the forehead of the adult head is yellow or milky white, in a copper bell shape, with no black spot in the middle (Figure 54), it is determined to be male;

[0027] 3. Adult sex identification: Remove the abdomen of each adult of the above-mentioned Propylaea indica from each group, dissect the external genitalia under a stereo microscope using forceps and a dissecting needle, determine the sex, and perform statistical analysis to verify the accuracy of the results of the above-mentioned rapid identification method for adult Propylaea indica. If the abdomen contains ovaries, it is determined to be female; if the abdomen contains testes, it is determined to be male.

[0028] 4. Result analysis: The rapid identification method of the present invention was used to identify the sex of each group of Propylae beetle adults, among which Group 1 had 102 males and 98 females; Group 2 had 105 males and 95 females; Group 3 had 99 males and 101 females. The traditional dissection of external reproductive organs was used to identify the sex of each group of Propylae beetle adults determined by the above method, among which Group 1 had 101 males and 98 females; Group 2 had 104 males and 95 females; Group 3 had 99 males and 101 females. It can be seen that the results of sex identification of Propylae beetle adults using the rapid identification method of the present invention are almost consistent with the results of dissecting external genitalia, among which the accuracy of female adult identification is 100%, and the accuracy of male adult identification is greater than 99%. The traditional Propylae beetle sex identification technology mainly distinguishes by dissecting reproductive organs under a microscope. Although this method has high accuracy, it requires killing the insect body and the operation is very complicated. The present invention can distinguish the sex of adults by only comparing whether there is a black spot in the middle of the forehead of the adult head. Further analysis shows that the 1% error rate of rapid identification of males in Group 1 comes from personnel error, which may be related to fatigue, and the 1% error rate of rapid identification of males in Group 2 comes from individual differences, that is, there are very few female adults in the ladybug population whose triangular spots on the head are not completely blackened, but only dim in color, leading to misjudgment. After subsequent dissection of 3,000 female protoceras, it was found that such abnormal females accounted for about 3%. Further analysis shows that such female ladybugs have triangular spots on their foreheads that are not completely blackened or the triangles are incompletely trapezoidal, or the triangular spots are extremely small, which are individual differences. When rapidly identifying the sex of adult protoceras, adults with unclear characteristics of lossless rapid identification of sex can be discarded, and the accuracy rate of male discrimination can reach 100%.

[0029] In addition, according to calculations, the anatomical identification method only requires fixing the protoceratops, dissecting its abdomen, and searching for reproductive systems such as testes or ovaries, which takes about 4 minutes; while the rapid identification method does not require fixing the protoceratops, and can be identified while it is crawling, which takes about 10 seconds. Compared with the traditional anatomical identification method, the rapid identification method takes less time and is more efficient.

[0030] Table 1 Comparison of sex identification results of Propylaea by rapid identification method and anatomical determination method

[0031]

[0032] Example 2: Rapid identification of sex of field-collected Propylaea adults

[0033] 1. Test insect source: In August 2022, 800 adult ladybugs were collected from the corn fields of the East Field Experimental Base of the Cotton Research Institute of the Chinese Academy of Agricultural Sciences and brought back indoors for sex identification, with 200 in each group, for a total of 4 groups.

[0034] 2. Rapid identification of adult sex: First, observe the morphological characteristics of the forehead of the head one by one under a stereoscope, determine the sex, and make statistical analysis. If the forehead of the adult head is yellow or milky white, with a black spot in the middle, in a triangular shape (Figure 51), or the top of the black spot is connected to the pronotum, resembling an hourglass shape (Figure 52), it is determined to be female; if the forehead of the adult head is yellow or milky white, in the shape of a copper bell, with no black spot in the middle (Figure 54), it is determined to be male;

[0035] 3. Adult sex identification: Remove the abdomen of each adult of the above-mentioned Propylaea indica from each group, dissect the external genitalia under a stereo microscope using forceps and a dissecting needle, determine the sex, and perform statistical analysis to verify the accuracy of the results of the above-mentioned rapid identification method for adult Propylaea indica. If the abdomen contains ovaries, it is determined to be female; if the abdomen contains testes, it is determined to be male.

[0036] 4. Result analysis: The rapid identification method of the present invention was used to identify the sex of each group of Propylae beetles, among which group 1 had 96 males and 104 females; group 2 had 108 males and 92 females; group 3 had 110 males and 90 females; group 4 had 105 males and 95 females. The traditional dissection of external reproductive organs was used to identify the sex of each group of Propylae beetles, among which group 1 had 96 males and 104 females; group 2 had 108 males and 92 females; group 3 had 110 males and 90 females; group 4 had 105 males and 95 females. It can be seen that the results of sex identification of Propylae beetles adults using the rapid identification method of the present invention are completely consistent with the results of dissecting external genitalia, and the accuracy rate of each group is 100%. The traditional sex identification technology of Propylae beetles is mainly distinguished by dissecting reproductive organs under a microscope. Although this method has high accuracy, it needs to kill the insect body and the operation is very complicated. The invention can distinguish the sex of the adult insects by only comparing whether there is a black spot in the middle of the forehead of the adult insects.

[0037] Table 2 Comparison of sex identification results of Propylaea by rapid identification method and anatomical identification method

[0038]

[0039] Those skilled in the art should understand that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for rapid sex identification of adult protea beetles, characterized in that: The following steps are involved: (1) Collecting adult Propylaea; (2) Characteristics of rapid sex identification of adult Propylaea, 1) The adult female of the Propylaea is characterized by a triangular or hourglass-shaped black spot in the middle of the forehead. 2) The adult male of the Propylaea is characterized by the absence of a triangular black spot in the middle of the forehead of the head, which is shaped like a yellow or milky white copper bell.

2. A method for rapid sex identification of Propylaea adults according to claim 1, characterized in that: The described Propylaea adults are Propylaea adults within the 3rd to 30th day of emergence.

3. A method for rapid sex identification of Propylaea adults according to claim 1, characterized in that: The elytra color spots of the adult Propylaea are in a tortoise-like shape, and the forehead of the head is yellow or milky white.

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