Lepidoptera larva age determination caliper

Abstract

The utility model relates to a lepidoptera larva instar determination caliper, the caliper comprises a body length measuring area (1) and a head width measuring area (2), the body length measuring area (1) is provided with a plurality of independent body length scales, and each body length scale corresponds to the body length of the lepidoptera larva at different instar; the head width measuring area (2) is provided with a plurality of light holes, and the aperture of each light hole corresponds to the head width of lepidoptera larvae at different ages. The Lepidoptera larva instar judging caliper is simple in structure and easy to use, and the Lepidoptera larva instar can be determined more accurately by measuring the head width and the body length.

Description

Technical Field

[0001] The utility model relates to an insect research and investigation instrument, and more specifically, to an auxiliary tool for judging the instar of Lepidoptera larvae.

Background Art

[0002] It is of great significance to clarify the instar of Lepidoptera larvae and accurately identify the larval instar for pest prediction and prevention strategy formulation. Instar division can timely and accurately predict the growth time of the pest population, enabling the best control effect of pesticides. For example, young larvae are in the initial stage of development and have poor resistance to pesticides, which is a critical period for control. Currently, in the monitoring of Lepidoptera pests, the larval instar is mainly determined by measuring parameters such as the head width, head length, body width, body length, and body color of the larvae with tools such as rulers and vernier calipers. This requires the investigator to have a good professional foundation and be able to remember the characteristics of different instars of each pest. Therefore, the investigation efficiency is not high, and it is easy to be confused and misjudged.

[0003] Chinese Utility Model Patent CN 201620439181 discloses a determination card for the instar of Plutella xylostella larvae, which determines the head width of the larvae through the light-transmitting dots on the card to quickly determine the instar of Plutella xylostella larvae. However, only judging the instar by a single head width makes the investigation conclusion prone to confusion. Chinese Utility Model Patent CN 202221476261 discloses a size measuring device for Lepidoptera insects, including a base and a slidable module, which is used to specifically measure the length, width, and height of the insect body, and the operation steps are cumbersome.

Content of the Utility Model

[0004] To solve the above technical problems, the utility model provides a caliper for judging the instar of Lepidoptera larvae, which comprehensively and quickly judges the instar of Lepidoptera larvae by comparing the head width and body length of the larvae with the caliper.

[0005] To achieve the above purpose, the utility model provides a caliper for judging the instar of Lepidoptera larvae. The caliper includes a body length measurement area (1) and a head width measurement area (2), and is characterized in that the body length measurement area (1) is provided with six independent body length scales, and each body length scale corresponds to the body length of Lepidoptera larvae from the first instar to the sixth instar; the head width measurement area (2) is provided with six light-transmitting holes, and the aperture of each light-transmitting hole corresponds to the head width of Lepidoptera larvae from the first instar to the sixth instar.

[0006] The maximum measurement value of the body length scale is consistent with the body length of Lepidoptera larvae at each instar, and the diameter of the light-transmitting hole is consistent with the head width of Lepidoptera larvae at each instar.

[0007] As a preferred embodiment of the present invention, the lepidopteran larvae are rice stem borers, and the measuring ranges of the six body length scales are 1.7-2.7 mm, 4.0-5.0 mm, 7.0-7.5 mm, 9.0-12.0 mm, 17.0-19.0 mm and 20.0-25.0 mm, respectively, and the smallest scale is millimeters; the apertures of the light-transmitting holes are 0.2-0.3 mm, 0.5-0.6 mm, 0.8-0.9 mm, 1.1-1.2 mm, 1.4-1.5 mm and 1.7-1.8 mm, respectively.

[0008] The distribution of head width and body length of the first to sixth instar larvae of the rice stem borer is shown in Table 1:

[0009] Table 1 Distribution of head width and body length of the first to sixth instar rice borer

[0010]

[0011] Preferably, the apertures of the body length scales and the light-transmitting holes are set according to the maximum values, that is, the measuring ranges of the six body length scales are 2.7mm, 5.0mm, 7.5mm, 12.0mm, 19.0mm and 25.0mm respectively; the apertures of the light-transmitting holes are 0.3mm, 0.6mm, 0.9mm, 1.2mm, 1.5mm and 1.8mm respectively.

[0012] The method for using the lepidopteran larvae age determination caliper of the present invention is as follows: the first step is to place the caliper horizontally, place the rice stem borer larvae to be measured near the scale, wait for the larvae to crawl freely and stretch naturally, and then move the caliper to find the current scale with the maximum measurement value longer than the body length, and the maximum measurement value next to the current scale is shorter than the larvae body length, then determine the larvae age to be the age corresponding to the current scale; if the body length of the rice stem borer exceeds the longest scale, the rice stem borer larvae is at the highest age;

[0013] Step 2: Place the caliper vertically and place the larvae to be tested near the circular hole. After the larvae crawl freely and place their heads into the circular hole, illuminate the caliper with a light source perpendicular to the caliper to observe whether light is transmitted through both sides of the insect's skull. If a light beam is observed in a certain light-transmitting hole, but no light beam is observed in the light-transmitting hole with the second largest diameter, the age of the larvae is determined to be the age corresponding to the current circular hole. If no light beam is observed in the circular hole with the largest diameter, the larvae are at the highest age.

[0014] The third step: age determination. Combine the results of the first step with the results of the second step. If both steps meet the same age, it is determined to be that age. If the results do not match, it is judged based on body color, body width and other characteristics.

[0015] As another preferred embodiment of the present utility model, the lepidopteran larvae are Plutella xylostella. The ranges of the four body length scales are 1.3 - 2.0 mm, 2.0 - 3.0 mm, 3.0 - 5.0 mm, and 5.0 - 7.0 mm respectively, and the apertures of the light-transmitting holes are 0.15 - 0.18 mm, 0.24 - 0.27 mm, 0.37 - 0.43 mm, and 0.56 - 0.64 mm respectively.

[0016] The head widths and body lengths of the first to fourth instar larvae of Plutella xylostella are distributed as shown in Table 2:

[0017] Table 2 Distribution of head width and body length of the first to fourth instar larvae of Plutella xylostella

[0018]

[0019] Preferably, the ranges of the body length scales and the apertures of the light-transmitting holes are set according to the maximum values. The ranges of the four body length scales are 2.0 mm, 3.0 mm, 5.0 mm, and 7.0 mm respectively, and the apertures of the light-transmitting holes are 0.18 mm, 0.27 mm, 0.43 mm, and 0.64 mm respectively.

[0020] As another preferred embodiment of the present utility model, the lepidopteran larvae are Spodoptera exigua. The ranges of the five body length scales are 1.2 - 2.2 mm, 2.5 - 5.0 mm, 4.5 - 7.0 mm, 7.0 - 14.0 mm, and 13.0 - 28.0 mm respectively, and the apertures of the light-transmitting holes are 0.1 - 0.2 mm, 0.3 - 0.4 mm, 0.6 - 0.7 mm, 0.9 - 1.0 mm, and 1.1 - 1.2 mm respectively.

[0021] The head widths and body lengths of the first to fifth instar larvae of Spodoptera exigua are distributed as shown in Table 3:

[0022] Table 3 Distribution of head width and body length of the first to fifth instar larvae of Spodoptera exigua

[0023]

[0024] Preferably, the ranges of the body length scales and the apertures of the light-transmitting holes are set according to the maximum values. The ranges of the five body length scales are 2.2 mm, 5.0 mm, 7.0 mm, 14.0 mm, and 28.0 mm respectively, and the apertures of the light-transmitting holes are 0.2 mm, 0.4 mm, 0.7 mm, 1.0 mm, and 1.2 mm respectively.

[0025] In the present utility model, for the convenience of observation, the caliper is made of light-impermeable material.

[0026] Among them, the light-transmitting holes can be made into through holes, or a circular light-transmitting area can be formed by printing the area outside the light-transmitting holes.

[0027] As another preferred embodiment of the present utility model, the body length scales and the light-transmitting holes are arranged according to their lengths and diameters, and are correspondingly distributed at both ends of the caliper in sequence.

[0028] The number of scales, the maximum measurement value, the number of the light-transmitting holes, and the diameters should be consistent with the number and distribution of the corresponding pest instars. The scales and the light-transmitting holes are evenly distributed at both ends of the caliper according to their lengths and diameters, so as to avoid being too dense.

[0029] As another preferred embodiment of the present utility model, the corresponding instars are marked on the body length scales and the light-transmitting holes.

[0030] Preferably, the caliper for determining the instar of lepidopteran larvae of the present utility model can be made of a conventional plastic material sheet or a metal material sheet, and its thickness can be 0.8 - 3 mm.

[0031] The caliper for determining the instar of lepidopteran larvae of the present utility model has a simple structure and is easy to use. By measuring the head width and the body length, the instar of lepidopteran larvae can be more accurately confirmed.

Description of the Drawings

[0032] Figure 1 is a schematic structural diagram of the present utility model;

[0033] Figure 2 is the caliper for determining the instar of lepidopteran larvae in Example 2;

[0034] Figure 3 is the caliper for determining the instar of lepidopteran larvae in Example 3;

[0035] Wherein: 1 - body length measurement area; 2 - head width measurement area.

Specific Embodiments

[0036] The following embodiments are used to explain the technical solution of the present utility model non - restrictively.

[0037] Example 1

[0038] As Figure 1 shown, the caliper for determining the instar of lepidopteran larvae is used to determine the instar of the larvae of Chilo suppressalis. The caliper is provided with scales and light - transmitting holes. The number of scales is 6, and the maximum measurement values of the scales are 2.7 mm, 5.0 mm, 7.5 mm, 12.0 mm, 19.0 mm, and 25.0 mm respectively; the number of the light - transmitting holes is 6, and the diameters are 0.3 mm, 0.6 mm, 0.9 mm, 1.2 mm, 1.5 mm, and 1.8 mm respectively.

[0039] The steps of using the caliper to determine the instar of the larvae are as follows.

[0040] Step 1: Horizontally place the caliper, put the rice stem borer larvae to be measured near the scale, wait for them to crawl freely, after natural elongation, move the caliper to find the current scale where the maximum measured value is longer than the body length, and the maximum measured value second only to the current scale is shorter than the body length of the larvae, then determine that the larval instar is the instar corresponding to the current scale; if the body length of the rice stem borer exceeds the longest scale, then the rice stem borer larvae are in the highest instar;

[0041] Step 2: Vertically place the caliper, put the pest larvae to be measured near the round hole, wait for them to crawl freely and put their heads into the round hole, use a light source perpendicular to the caliper to irradiate the caliper, observe whether both sides of the pest's skull are transparent. If a light beam is observed in a certain transparent hole and no light beam is observed in the transparent hole with a diameter second only to the current round hole, then determine that the larval instar is the instar corresponding to the current round hole. If no light beam is still observed in the round hole with the largest diameter, then the larvae are in the highest instar;

[0042] Step 3: Instar determination. Combine the results of the first step and the second step. When both steps meet the same instar, then determine it as that instar. If the results do not match, then judge by characteristics such as body color and body width.

[0043] Example 2

[0044] Such as Figure 2 The caliper for judging the instar of Lepidoptera larvae shown is used to judge the instar of diamondback moth larvae. The caliper is provided with scales and transparent holes. The number of scales is 4, and the maximum measured values of the scales are 2.0 mm, 3.0 mm, 5.0 mm, and 7.0 mm respectively; the number of transparent holes is 4, and the diameters are 0.18 mm, 0.27 mm, 0.43 mm, and 0.64 mm respectively.

[0045] The steps of using the caliper to judge the instar of diamondback moth larvae are as follows,

[0046] Step 1: Horizontally place the caliper, put the diamondback moth larvae to be measured near the scale, wait for them to crawl freely, after natural elongation, move the caliper to find the current scale where the maximum measured value is longer than the body length, and the maximum measured value second only to the current scale is shorter than the body length of the larvae, then determine that the larval instar is the instar corresponding to the current scale; if the body length of the diamondback moth exceeds the longest scale, then the diamondback moth larvae are in the highest instar;

[0047] Step 2: Vertically place the caliper, put the pest larvae to be measured near the round hole, wait for them to crawl freely and put their heads into the round hole, use a light source perpendicular to the caliper to irradiate the caliper, observe whether both sides of the pest's skull are transparent. If a light beam is observed in a certain transparent hole and no light beam is observed in the transparent hole with a diameter second only to the current round hole, then determine that the larval instar is the instar corresponding to the current round hole. If no light beam is still observed in the round hole with the largest diameter, then the larvae are in the highest instar;

[0048] Step 3: Age determination. Combine the results of the first step and the second step. If both steps meet the same age period, then it is determined as that age period. If the results do not match, then judge by characteristics such as body color and body width.

[0049] Example 3

[0050] As Figure 3 shown in the caliper for judging the instar of Lepidoptera larvae, which is used to judge the instar of Spodoptera exigua larvae. The caliper is provided with scales and light-transmitting holes. The number of scales is 5, and the maximum measured values of the scales are 2.2 mm, 5.0 mm, 7.0 mm, 14.0 mm, and 28.0 mm respectively; the number of the light-transmitting holes is 5, and the diameters are 0.2 mm, 0.4 mm, 0.7 mm, 1.0 mm, and 1.2 mm respectively.

[0051] The steps of using the caliper to judge the instar of Spodoptera exigua larvae are as follows.

[0052] Step 1: Horizontally place the caliper, place the Spodoptera exigua larvae to be measured near the scale, wait for it to crawl freely, and after natural elongation, move the caliper to find the current scale whose maximum measured value is longer than the body length, and the maximum measured value second only to the current scale is shorter than the body length of the larvae, then determine the instar of the larvae as the instar corresponding to the current scale; if the body length of Spodoptera exigua exceeds the longest scale, then the Spodoptera exigua larvae are in the highest instar.

[0053] Step 2: Vertically place the caliper, place the pest larvae to be measured near the round hole, wait for it to crawl freely, put its head into the round hole, use a light source perpendicular to the caliper to irradiate the caliper, and observe whether the two sides of the pest's skull are light-transmitting. If a light beam is observed in a certain light-transmitting hole and no light beam is observed in the light-transmitting hole whose diameter is second only to the current round hole, then determine the instar of the larvae as the instar corresponding to the current round hole. If no light beam is still observed in the round hole with the largest diameter, then the larvae are in the highest instar.

[0054] Step 3: Age determination. Combine the results of the first step and the second step. If both steps meet the same age period, then it is determined as that age period. If the results do not match, then judge by characteristics such as body color and body width.

Claims

1. A caliper for determining the instar of lepidopteran larvae, the caliper comprising a body length measurement area (1) and a head width measurement area (2), characterized in that The body length measurement area (1) is provided with independent multiple body length scales, and each body length scale corresponds to the body length of different instars of lepidopteran larvae; the head width measurement area (2) is provided with multiple light-transmitting holes, and the aperture of each light-transmitting hole corresponds to the head width of different instars of lepidopteran larvae respectively.

2. The lepidopteran larva instar judgment caliper according to claim 1, characterized in that The lepidopteran larvae are Chilo suppressalis. The body length measurement area (1) is provided with six body length scales, and the measurement ranges are 1.7 - 2.7 mm, 4.0 - 5.0 mm, 7.0 - 7.5 mm, 9.0 - 12.0 mm, 17.0 - 19.0 mm, and 20.0 - 25.0 mm respectively, and the minimum scale is in millimeters; the head width measurement area (2) is provided with six light-transmitting holes, and the apertures of the light-transmitting holes are 0.2 - 0.3 mm, 0.5 - 0.6 mm, 0.8 - 0.9 mm, 1.1 - 1.2 mm, 1.4 - 1.5 mm, and 1.7 - 1.8 mm respectively.

3. The caliper for judging the instar of lepidopteran larvae according to claim 2, characterized in that The measurement ranges of the six body length scales are 2.7 mm, 5.0 mm, 7.5 mm, 12.0 mm, 19.0 mm, and 25.0 mm respectively; the apertures of the light-transmitting holes are 0.3 mm, 0.6 mm, 0.9 mm, 1.2 mm, 1.5 mm, and 1.8 mm respectively.

4. The lepidopteran larva instar judgment caliper according to claim 1, characterized in that The lepidopteran larvae are Plutella xylostella. The body length measurement area (1) is provided with four body length scales, and the measurement ranges are 1.3 - 2.0 mm, 2.0 - 3.0 mm, 3.0 - 5.0 mm, 5.0 - 7.0 mm; the head width measurement area (2) is provided with four light-transmitting holes, and the apertures of the light-transmitting holes are 0.15 - 0.18 mm, 0.24 - 0.27 mm, 0.37 - 0.43 mm, 0.56 - 0.64 mm respectively.

5. The lepidopteran larva instar judgment caliper according to claim 4, characterized in that The measurement ranges of the four body length scales are 2.0 mm, 3.0 mm, 5.0 mm, 7.0 mm respectively, and the apertures of the light-transmitting holes are 0.18 mm, 0.27 mm, 0.43 mm, 0.64 mm respectively.

6. The caliper for determining the instar of lepidopteran larvae according to claim 1, wherein The lepidopteran larvae are Spodoptera exigua. The body length measurement area (1) is provided with five body length scales, and the measurement ranges are 1.2 - 2.2 mm, 2.5 - 5.0 mm, 4.5 - 7.0 mm, 7.0 - 14.0 mm, 13.0 - 28.0 mm; the head width measurement area (2) is provided with five light-transmitting holes, and the apertures of the light-transmitting holes are 0.1 - 0.2 mm, 0.3 - 0.4 mm, 0.6 - 0.7 mm, 0.9 - 1.0 mm, 1.1 - 1.2 mm respectively.

7. The caliper for judging the instar of lepidopteran larvae according to claim 6, wherein The measurement ranges of the five body length scales are 2.2 mm, 5.0 mm, 7.0 mm, 14.0 mm, 28.0 mm respectively, and the apertures of the light-transmitting holes are 0.2 mm, 0.4 mm, 0.7 mm, 1.0 mm, 1.2 mm respectively.

8. The lepidopteran larva instar determination caliper according to any one of claims 1 to 7, characterized in that The caliper is made of light-impermeable material, and the light-transmitting holes are through holes.

9. The caliper according to any one of claims 1 to 7, characterized in that The body length scales and the light-transmitting holes are arranged according to length and diameter size, and are correspondingly distributed at both ends of the caliper in sequence.

10. The caliper according to any one of claims 1 to 7, characterized in that The corresponding instars are marked on the body length scales and the light-transmitting holes.

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