Table 7-6 Lists of the main pests of Larix principis-rupprechtii in the Mengbian Forestry Bureau

Pest name

Chemical conversion rate %

Feathering rate %

Sex ratio

(male and female)

Egg production (grain)

Egg loss rate %

Hatching rate %

Overwintering larvae loss rate %

Number of juvenile larvae (articles)/ autumn tufts (articles, heads, grains)

Larch caterpillar

83

54

1:0.8

300

15

80

35

2 to 4 instar larvae 0.65/1 (larvae)

Larch

81.5

1:1.3

220

6

89

1 instar larvae 65.2 rods/head (蛹)

Larix gmelinii

85

95

1:0.9

32

90

1st instar larvae 12.3/1 (preliminary)

Larix principis

15

0.85 3rd instar larvae / 1 larva

Gypsy moth

600

30

50

0.35 1st instar larvae/1 (egg)

Larch cone flower fly

88

51

1:0.8

36

10

80

7.34 1 instar larvae/1 head (蛹)

Note: It is the result of system monitoring in the past 10 years

7-7 Classification of Major Pests of Larix principis-rupprechtii in the Mengbian Forestry Bureau

Insect species

Insect

unit

the level of danger

Forest age

+

++

+++

Larch caterpillar

3 to 4 instar larvae

Article/Strain

5 to 20

21 to 40

40 or more

5 to 10 years

10-30

31~50

above 50

11 to 20 years

20 to 40

41 to 70

More than 70

20 years or more

Larch

1st instar larva

Article/Strain

400 to 1200

1201 to 3000

More than 3000

15 to 20 years

700 to 1700

1701~3500

3500 or more

21 to 30 years

Larix gmelinii

1st instar larva

Article/Strain

700 to 1200

1201 to 2500

More than 2500

15 to 20 years

100 to 1500

1501 to 3000

More than 3000

21 to 30 years

Larix principis

larva

Head / 100cm extension sticks

10 to 20

21 to 40

40 or more

Gypsy moth

1st instar larva

Article/Strain

20 to 40

41 to 70

More than 70

5 to 15 years

30~60

61 to 100

More than 100

16-25 years

Larch cone flower fly

1st instar larva

Article/Strain

30 to 150

151~300

More than 300

About 15 years

Note: The criteria for the classification of hazard levels are:

1. Leaf-feeding pests: 1/3 of needle damage is light (+), 1/3 to 2/3 is medium (++), and 2/3 or more is heavy (+++).

2. Seed pests: The actual damage rate of 10% or less is light (+), 11 to 12% is medium (++), and 20% or more is heavy (+++).

Section III Main rodents of Larix principis-rupprechtii

Rat poisoning is one of the four pests. Among rodents, the species of rats is the most. According to relevant data, there are more than 2,800 kinds of rodents on Earth, of which there are more than 180 species in China. However, the rodent species of Larix principis-rupprechtii that was endangered in the Mengbian Forest Management Bureau of Hebei Province was mainly brownbacked. This section will only expound on the rat.

First, clethrionomys rufocanus sunderall

Alias: red hair mouse, mountain mouse.

1. Taxonomic status in rodents Rodentia rutiformes Myomorpha hamsters cricetidae vole subfamily Microtinae genus clethrionomys

2. Distribution Heilongjiang, Jilin, Liaoning, Inner Mongolia, Hebei, Shaanxi, Gansu, Sichuan, Hubei, Jiangxi and Xinjiang.

3, recognition feature length 85 ~ 115mm (average 97mm), tail length 26 ~ 36 mm (average 30.7 mm) is about 1/3 of the body length; ear shorter, an average of 12.5mm; eye round, black; smaller limbs . From the forehead, the neck to the buttocks, the back hair is more pronounced red-brown hair, and the hair base is grayish-black; the hair on both sides of the body is light gray and gray hair on the abdomen; the tail hair is short, the back is grayish black, and the belly is grayish white.

Skull: The skull is relatively thick and short, with a concave groove in the center of the eye to guide the front end of the frontal bone. The skull is long, the bubble is not large, and the cheekbones are slightly thick.

Teeth: The teeth are larger. M1 and M2 have five closed triangles and M3 has four. The last tooth blade often communicates with the front triangle, and slightly protrudes backwards. The inside and outside sides each form three protruding angles, which can be distinguished from the red back plane.

4, living habits

(1) Inhabiting environment: After the logging of the original broad-leaved secondary forest is inhabited by the Mengfu Forest Management Bureau in Hebei Province, the coniferous and broad-leaved young forest land formed by artificial regeneration is promoted. In the peak year of the rat population, there are more numbers in the mountains, in the mountains and on the slopes. In the middle or low years of quantity, the forest is often leeward and leeward in forests with dense weeds, bushes, wild roses, and flat hazel.

(2) Cave structure: Caves are built under the roots, fallen wood, cutting roots, shrubs, grasses, and litter layers. The depth of the cave is 5 to 10 cm, the depth is 30 cm, and the caverns are two or more. Runway connection. In winter, there is a hole in the snow and there are criss-crossing holes in the snow layer.

(3) Feeding habits and hazards: The rats have seasonal differences in diet, and prefer the green part of the plants (spring stems, young leaves) in the summer; after spring (after surface thawing) and after the fall of the fall, the rats eat the young leaves of the plants and The underground stems are the dominant species. They feed on seeds and bark during the winter, mainly through the nurturing of trees such as larch, pine and hawthorn, resulting in the death or growth of larch and young seedlings, and dry branches and branches.

The degree of harm of the same species of the tree of different ages is different. Generally, young trees within 10 years of age suffer the most. From 10 to 15 years old, the victim is lighter, and 15 or more students are rarely killed.

The hazards of larch and Pinus sapling young trees are generally from November to February of the following year, and they are mostly harmful at night and in the morning. The damage was mild and the strips were stripped from the base stems. The direction was to the southeast: the phloem was more southeastwards. Moderate-to-major hazards are mostly ring-skinned, and the ring width is usually 4 to 10 cm, and it is 15 cm or more. After peeling, there are rodent marks to distinguish them from livestock.

5. Occurrence characteristics In the forest area of ​​the Mengzi Forest Management Bureau, from April to May, the rat was flowering when the native Pulsatilla spp., and it was the first stage of reproduction when the Acanthopanax erected leaves. The breeding season was from June to August. Each year, 2 to 4 babies are born and 4 to 7 babies are born. The average is 5 to 6 and their life span is about 1.5 years. Stop breeding in October.

The number of rat populations varies regularly in different years. Generally there is a high bee every three years, and the interval between two peak years is two years. The reason for the cyclical changes in the population of the mouse is closely related to the amount of strong seeds in the forest. In the second year of the harvest of the dominant tree species, the population of the rat population soared into the peak year.

6, feeding observation young rats afraid of light, afraid of heat. Under plenoptic conditions, pups die for 3 days under adequate food conditions. The shading conditions are normal. Adult rats like to eat foods with high water content, such as fruits (apples, pears) berries (tomatoes) vegetables (such as cucumber, eggplant, etc.), under the conditions of insufficient water, less dry food such as cornmeal. Under the condition of waterless, it can maintain normal growth and development by cultivating fresh straw, such as Artemisia ordosica. Observations were made of cornmeal and wheat as feed. Wheat was eaten less, corn meal less, and rotten hay was rejected. Under conditions of sufficient food, different littermates and sub-adults were killed in the same cage. When there is not enough food, the individuals will eat together with the nest. Adult rats were more timid and suspicious than young rats. Their foraging behavior was more regular than that of young rats. There were more activities in the evening and early morning.

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