There are different specimen preparation methods based on the characteristics of the insect itself (such as body, size, softness and hardness), life stage (such as larvae or adults), and research needs. It can be mainly divided into the following types:

1. Needle insertion method

This method is suitable for insects with larger bodies and harder bodies. This is also the most common one. Specimen Preparation Methods. After collection, before the specimens are dry, insect needles are inserted into the specimens to adjust their posture or spread their wings.

Insects such as moths, butterflies, dragonflies, and bees need to spread their wings. The wing-spreading board is made of softer wood, about 1 foot long, and the wooden strips on both sides are 3 inches wide and slightly inclined inward. One of them is movable to adjust the width of the seam between the boards. Cork strips are installed at the bottom of the groove between the two boards. When spreading the wings, insert the needle-inserted specimen on the cork board at the bottom of the tank to make the gap in the middle fit the insect body. Then use a small insect needle to insert into the thicker wing veins and pull the left and right forewings forward. In Lepidoptera, the trailing edges of the wings are slightly tilted forward. For flies and wasps, the tips of the forewings are aligned with the head. Temporarily fix the forewings on the wing-spreading plate, and then pull the hindwings. The leading edge of the moth's hindwing is pressed under the trailing edge of the forewing, making it symmetrical and fully flattened. Finally, press it with a smooth paper strip, fix it with a pin, put it in a dry place, and remove it after the specimen is completely dry.

Needle insertion position:

For Lepidoptera, Odonata, and Diptera insects, insert the needle slightly to the right of the center of the thorax, leaving a complete center of the back Line coming.

For Coleopteran insects, insert the needle into the upper left corner of the right elytra so that the insect needle goes right between the middle and hind legs on the ventral surface, so as not to damage the basal fossa that is the classification characteristic of Coleopteran insects. .

For Hemipteran insects, insert the needle to the right of the center of the scutellum so that the mouthpart groove on the ventral surface can be completely preserved

Insects of the order Mantis and Orthoptera , insert the needle on the right side of the earth at the base of the middle chest.

Hymenoptera insects should be inserted in the center of the thorax.

Pin height: The top of the needle from the insect to the top accounts for about 1/3 of the needle length.

2. Microneedle and adhesive method

For some small insects, ordinary insect needles are too large to be inserted into the insect body. In this case, smaller microneedles are needed. Insert the insects, then insert microneedles into small pieces of cork, and then insert regular insect needles into the cork pieces. If there are smaller insects, you can use glue to stick the right middle part of the insect's thorax to the tip of a small triangular paper, and then use an ordinary insect needle to insert the triangular paper.

The pin insertion and shaping can be completed on the foam board, and the position is fixed with a pin. After the specimen becomes hard, remove it and store it in a specimen box.

Specimen boxes can be purchased at plant protection equipment stores. Note that camphor should be placed in the specimen boxes to prevent insect infestation.

3. Dipping method

Some insects have soft body surfaces, such as termites or the larvae of completely metamorphosed insects, which cannot be made into dried specimens for needle insertion. At this time, the insect body can be soaked in the liquid. Usually, the insect tissue is fixed with special fixative or hot water, and then soaked in 95% alcohol for preservation. Note that the glass bottle for storage must be sealed, otherwise the alcohol will easily evaporate. Sometimes the specimen becomes dehydrated or the body fluids of the insect body leak out, causing the alcohol concentration to become low. At that time, the alcohol must be replaced several times.

4. Slide specimens

Slide specimens are suitable for very small insects, and their morphological characteristics must be observed with a microscope or magnifying glass.

For example, lice, fleas, aphids, etc. The general steps are to soak the collected specimens in 10% potassium hydroxide solution, soften the skeleton of the insect body for one day, then take it out, wash it with distilled water, and dye it with magenta and other dyes if necessary to facilitate observation.

Then, a series of dehydration is carried out with alcohol of equal concentration of 50, 60, 70, 80, 90, and 100%, and then the slide is sealed with gum arabic, and after drying for 2-3 weeks, you are done