CN113678817A

CN113678817A - Method for preparing specimen of larva of rhynchophorus ferrugineus

Info

Publication number: CN113678817A
Application number: CN202110882539.4A
Authority: CN
Inventors: 郭朴原; 魏健; 孙淦琳; 陈斌; 和淑琪
Original assignee: Yunnan Agricultural University
Current assignee: Yunnan Agricultural University
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2021-11-23
Anticipated expiration: 2041-08-02
Also published as: CN113678817B

Abstract

The invention relates to the field of specimen preparation, in particular to a method for preparing a red palm weevil larva specimen, which comprises three steps of larva treatment, sand grain filling and specimen drying, wherein the larva treatment mainly comprises larva dissection, viscera taking and redundant fat, the body wall and the muscle and trachea at the lower layer of the body wall are reserved, the larva is placed in boiling water for boiling for 3-6 minutes, the type of the sand grain filling is yellow sand, the yellow sand is filled to a position 5mm away from a larva incision, then the specimen is dried, the fire-fighting sand cushion white paper is used for drying, and the baking temperature is measured by judging the color of the white paper.

Description

Method for preparing specimen of larva of rhynchophorus ferrugineus

Technical Field

The invention relates to the field of specimen preparation, in particular to a method for preparing a red palm weevil larva specimen.

Background

The biological specimen is used as a physical carrier and a reference voucher of basic materials and species names of biological research, plays an important role in promoting the origin and development of various disciplines in the biological field, and can provide information of biological diversity, classification and historical distribution worldwide. Each specimen is unique and provides multidimensional information on species (biological, genetic, ecosystem diversity), space (location) and time (date), which plays an important supporting role in the protection of biodiversity.

Insects are the most various biological groups in the world, known insect species account for more than 1/2 of the whole known biological species, and the preparation of insect specimens is an important basis for displaying the abundant biological diversity of the earth and developing teaching and scientific research works. Conventionally, the preparation of insect larva specimens is more difficult than that of adult specimens, and the insect larva specimens can be kept for a long time while keeping the original morphological characteristics and body color. The traditional insect larva specimen preparation method comprises the following steps: dipping, inflation, body skin specimen, silica gel filling, and the like. With the continuous emergence of new materials and new technologies, the manufacturing method of insect specimens is also continuously improved.

Red palm weevil (Rhynchophorus ferrugineus) Belongs to Coleoptera, Arundinaceae and Pimenta, is originally produced in India of south Asia, is found in Zhongshan of Guangdong of China for the first time in the first 90 th, and harms coconut trees in Wenchang of Hainan in 1998 to cause serious economic loss. At present, the pesticide is distributed in a wide area in the south of Yangtze river, has the characteristics of strong reproductive capacity, wide parasitic plants, high control difficulty, high lethality rate, easy centralized outbreak and the like, can cause irreversible damage to the invasive arecaceae plants, and is listed as a quarantine pest for forestry and quarantine pest for entry plants in China. The larvae and pupae of the rhynchophorus ferrugineus live in the trunk of the plant of the Palmae, and the larvae cannot be in a larva state before the tree is not dead completely; the damaged plant needs to be sawed off to collect the larva, so that the preparation of a larva specimen is an important basis for developing teaching, scientific research and science popularization work of quarantine pests (such as life history, different pest state identification and the like) in colleges and universities.

The larva of the rhynchophorus ferrugineus has a body length of 40-45mm, a spindle shape (two thin ends and thick middle part), is fat in body shape, and has high fat and protein contents. When the specimen is prepared by the traditional method, the following defects are caused:

1. the dipping method comprises the following steps: the larva is boiled in boiling water to fix the protein (denature) in the larva, and then soaked in 75% -95% alcohol. The method has simple operation and the following disadvantages: 1) the body color of the larva can fade and the body shape can deform due to the water boiling of the specimen, and the original body color and shape can not be kept; 2) soaking in alcohol easily causes dissociation of larva tissues (namely, separation and disintegration of each part after softening);

2. the inflation method comprises the following steps: the internal organs of the worm body are pressed out of the worm body by a cylinder similar to a rolling pin, and then air is blown from the anus of the worm body, and the worm body is heated, dried and shaped while being blown. The method is generally used for manufacturing small larva specimens of lepidoptera and the like, and when the small larva specimens of the red palm weevil are manufactured, the defects are as follows: 1) the red palm weevil larva has larger body size and higher content of fat and protein in the body, and is not easy to extrude the internal organs of the larva; 2) the body of the red palm weevil larva is spindle-shaped, the gas quantity is not easy to control during blowing, so that the spindle shape of the larva is changed into a cylinder, and the original fold and the like on the body surface are easy to blow so as to lose the original morphological characteristics of the body surface of the larva; 3) the body wall of the larva of the red palm weevil is thin, the heating and drying temperature in the air blowing process is not easy to control, and the larva is very easy to scorch; 4) The cotton can be used for filling insects from the anus after being blown up, large cracks are easy to cause and difficult to recover, and if the cotton is not tightly filled, the deformation and other conditions are easy to occur, the cotton is excessively compacted and is easy to break the skin;

3. larva body skin specimen: simply cutting the larva from the midline of the abdomen, removing viscera, etc., and leaving one epidermis to prepare a body skin specimen; the operation method is simple, but the original form of the larva can not be displayed completely;

other methods, such as silica gel filled larval specimens, have relatively high costs and materials that are not readily available.

Disclosure of Invention

The invention mainly aims to provide a method for preparing a specimen of a red palm weevil larva so as to solve the problems in the prior art.

In order to achieve the above purpose, the invention provides the following technical scheme:

a method of making a specimen of rhynchophorus ferrugineus larvae comprising the steps of:

(1) larva treatment: taking a red palm weevil larva, boiling in boiling water for 2-90 seconds, taking out, pulling out a head shell, cutting off a part of the larva along the joint of the head shell and the back of a worm body by using a scalpel, wherein the cutting length is about half of the perimeter of the head shell, and keeping the joint of the head shell and the abdomen of the larva not cut off;

setting untreated, boiling water for 3 minutes, 5 minutes, 7 minutes, 9 minutes, five controls, observing every 30 minutes for a total of two hours, as shown in fig. 3, it was finally found that the samples treated for about 5 minutes had the best results, the untreated samples were completely blackened, the effects were not evident when the treatment time was too short, the treatment time was too long, the samples were too shrunken and were not easy to follow up.

(2) Filling sand grains: filling the treated insect body with proper amount of sand from the opening of the head shell to the tail part, wherein the filler is yellow sand (similar to the insect body in color) and has an average particle size of 0.125-0.25 mm. Compacting with tweezers once every filling, shaping with hands while filling, removing absorbent cotton with tweezers to fill and compact at 5mm position of the opening, adhering the head shell and the back with white latex when filling to be level with the opening, retracting the head shell, cleaning, and wiping to dry;

(3) drying the specimen: the fire control sand is filled in the stainless steel pot, and A4 white paper is laid on the fire control sand. The stainless steel pot is placed on a tripod, and the stainless steel pot is heated by an alcohol lamp. The worm body is placed on white paper, the head part of the worm body is close to the ignition part of the alcohol lamp, and the tail part of the worm body is far away from the ignition part of the alcohol lamp, so that the worm body is dried. Turning over the body of the worm every few minutes to uniformly heat the body of the worm until the body wall of the worm becomes hard, and taking out the worm.

Further, in the step (1), the larvae are living larvae, the larvae are boiled for 3-8 seconds until the larvae die, and after the digestive tracts, internal organs and fat of the larvae are taken out, the larvae are put into the boiling water again to be boiled for 4-6 minutes.

Further, in the step (1), the larvae are cryopreserved larvae, boiled for 2-5 seconds to be thawed, and after the digestive tracts, internal organs and fat of the larvae are taken out, the larvae are put into the boiling water again to be boiled for 3 minutes.

Further, in the step (2), the filled sand grains are yellow sand, and the average grain diameter is 0.125 mm-0.25 mm.

Further, in the step (3), 2-3 cm of sand elimination and prevention is filled in a stainless steel pot, the stainless steel pot is placed on a tripod, an alcohol lamp is used for heating, the worm body is placed on white paper, the head of the worm body is close to the ignition position of the alcohol lamp below the stainless steel pot, and the tail of the worm body is far away from the central ignition position for drying.

In the research, aiming at the characteristics of the red palm weevil larva, the traditional larva specimen preparation method is improved, and the method has the advantages of low preparation cost, simple material acquisition approach and simple process flow, and also has the following advantages:

1) the boiled water treatment time of the larvae of the red palm weevil is short, and the body color and the original shape of the body surfaces of the larvae are kept to the maximum extent;

2) aiming at the characteristic that the top end of the head of the red palm weevil retracts into the body, the traditional method for filling from the anus is changed, and the position where the top end of the head shell of the larva of the red palm weevil is connected with the body is filled by slotting, so that the larva body is easy to repair (namely, the crack of the larva body epidermis is not easy to generate, and the repaired position of the slotting has no difference from the original shape);

3) the traditional cotton filling mode is changed into the mode of filling with yellow sand grains, so that the original shape (including body surface wrinkles) of the insect body can be well maintained, the insect body is not easy to deform, the texture is well maintained, and the specimen is not easy to damage;

4) the newly manufactured specimen is dried by innovatively using a sand heating method, so that the problem that the heated specimen is easy to burn and discolor due to the fact that the surface of the red palm weevil is too thin can be avoided, and the normal body color of the worm body is kept;

5) the novel sand is used for placing a piece of white paper as an indicator for temperature regulation, and if the white paper turns yellow in the baking process, the temperature needs to be regulated if the temperature is too high.

Drawings

FIG. 1 shows a schematic representation of the process of the present invention for preparing a specimen of a larva of rhynchophorus ferrugineus;

FIG. 2 is a schematic representation of the body wall of a red palm weevil larva of the present invention after removal of the gut and internal organs;

FIG. 3 shows the morphology of the worms after boiling for different periods of time.

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific examples, and the materials involved in the invention are commercially available.

Example 1

1. Larva treatment

Taking a fresh red palm weevil larva, clamping the larva in boiling water by using tweezers, boiling for about 3-8 seconds, taking out the dead larva, slightly stretching out a head shell of the larva, cutting the head shell of the larva along the joint of the head shell of the larva and the back of the larva (about half of the circumference, namely the part of the head shell connected with the abdomen of the body is not cut), injecting 300ml of clear water into a culture dish with the diameter of 12cm, putting the larva into the clear water, stretching a tip tweezers from an opening, taking out the alimentary canal and the internal organs of the larva, avoiding puncturing the larva, and remaining the muscle below the body wall so that the body surface of the larva keeps the original and a special fold structure. If the muscle layer is not reserved, only the body wall is reserved, the worm body is easy to scorch and is fragile, and the body surface folds are not easy to maintain without muscle support, so that the forms of the larvae of the rhynchophorus ferrugineus cannot be expressed.

After the worm bodies are cleaned, the worm bodies are put into boiling water again to be boiled for 4-6 minutes, (the worm bodies need to be continuously turned to be uniformly heated in the boiling process), the boiling time is controlled to be about 5 minutes, the worm bodies shrink excessively after too long time, the larva forms are not easy to shape, the color of the specimen is not easy to be preserved after too short time, the specimen turns black after being placed in the air for a period of time, and the original body color of the worm bodies cannot be expressed; taking out the cooked larva with tweezers, cooling for 30s, cooling to reach temperature not scalding, and absorbing water on body surface and body cavity with absorbent paper (the absorbent paper is twisted into strip shape and inserted into body cavity of larva to absorb water in body cavity).

2. Filled sand

Filling the treated polypide with proper amount of yellow sand from the opening of head shell to tail, the average particle size of yellow sand is 0.125-0.25mm, compacting with tweezers each time, shaping with hands while filling (the red brown weevil larva is in spindle shape, i.e. head and tail are thinner and middle is thicker, so tail and head are thinner than middle part, natural transition, there is annular fold on the surface of red brown weevil larva, it needs to be shaped according to original appearance characteristics of larva), taking absorbent cotton with tweezers to remove when filling to the opening of about 5mm, filling bit by bit, compacting with tweezers during filling (the part is dried and then shrinks), filling to be level with the cut, bonding head shell and back with white latex, pressing head shell slightly towards chest, making the joint of head shell and back retract into chest, to restore its original living form while hiding the bond. The body surface is washed with clean water and wiped dry with a paper towel.

3. Specimen drying

Putting fire-fighting sand with the thickness of about 2-3 cm into a stainless steel pot (d =18cm, h =9 cm), putting a piece of white paper on the pot, putting the pot end on a tripod, igniting an alcohol lamp below the tripod, and heating; the body of the worm is placed on the white paper, the head part is close to the center (namely close to the ignition part of the alcohol lamp below the pot), and the tail part is far away from the center (namely far away from the lower part of the pot), so that the body of the worm is prevented from being burnt. The turn-over was recorded every few minutes and allowed to heat evenly until the body wall became hard, approximately half an hour (depending on the size of the worm).

Example 2

Generally, fresh larvae are not easily obtained, or the obtained fresh larvae are not easily raised and dead, and then the bodies of the dead larvae quickly turn black. Therefore, the obtained larva can be frozen in a refrigerator at the temperature of 20 ℃ below zero, the larva body can be kept from discoloring at low temperature, and the larva can be taken at any time. The frozen larvae are used as specimens, the larvae die and only need to be thawed, the larvae are placed in hot water for thawing, the time for cooking the larvae for the second time is shortened to 3 minutes according to the size of the larvae, except that the digestive tracts, internal organs and partial fat of the larvae are taken out, and the rest operations are the same as those in example 1.

Claims

1. A method of making a specimen of rhynchophorus ferrugineus larvae comprising the steps of:

(1) larva treatment: taking a first red palm weevil larva, boiling in boiling water for 2-90 seconds, taking out, pulling out a head shell, cutting off a part of the larva along the joint of the head shell and the back of the larva body by using a scalpel, putting the larva into clear water, extending a tip forceps from an opening, taking out the alimentary canal, internal organs and part of fat of the larva, keeping the body wall, muscles and air pipes attached to the body wall, boiling in boiling water for 3-6 minutes again, taking out the boiled larva, cooling until the larva can be touched by a hand without scalding, and completely absorbing water on the body surface and the body cavity of the larva by using water absorbing paper;

(2) filling sand grains: filling the treated insect body with a proper amount of sand particles from the opening of the head shell to the tail part by using a medicine spoon, compacting by using tweezers once each time, shaping by using hands while filling, taking absorbent cotton out by using the tweezers to perform filling compaction when the filling is carried out to the position of 5mm of the opening, adhering the head shell and the back part by using white latex when the filling is filled to be level with the cut, retracting the head shell, cleaning and wiping;

(3) drying the specimen: filling the sand for elimination and prevention into a stainless steel pot, putting a piece of white paper on the stainless steel pot, putting the insect body on the white paper, heating the stainless steel pot, turning over the insect body every few minutes to uniformly heat the insect body until the body wall is hardened, and taking out the insect body.

2. The method for preparing a specimen of rhynchophorus ferrugineus larvae according to claim 1, wherein in the step (1), the larvae are live larvae, the larvae are boiled for 2-90 seconds until the larvae die, the junction of the skull and the back is cut, the alimentary canal, internal organs and partial fat of the larvae are taken out, and then the larvae are put into boiling water to be boiled for 4-6 minutes again.

3. The method for preparing a specimen of rhynchophorus ferrugineus larvae according to claim 1, wherein in the step (1), the larvae are cryopreserved, boiled for 30-90 seconds to be thawed, cut at the junction of the head shell and the back, taken out of alimentary tracts, internal organs and fat of the larvae, and then put into boiling water again to be boiled for 3 minutes.

4. A method of preparing a specimen of rhynchophorus ferrugineus larvae according to claim 1, 2 or 3, wherein in step (2), the sand particles filled are yellow sand having an average particle size of about 0.125-0.25 mm.

5. The method for preparing the specimen of the larva of the rhynchophorus ferrugineus according to the claim 1, 2 or 3, wherein in the step (3), 2-3 cm of fire control sand is filled in a stainless steel pot, the stainless steel pot is placed on a tripod, an alcohol lamp is used for heating, the larva is placed on white paper, the head of the larva is close to the ignition position of the alcohol lamp below the stainless steel pot, and the tail of the larva is far away from the central ignition position for drying.