What are the general characteristics of the seven star ladybug?

The characteristics and life characteristics of ladybugs in "Insects" are as follows:

Features: Axe-shaped mandibular barbels, 4-segmented tarsal joints, and posterior baseline of the first web, which can be distinguished from other closely related species. Features such as short (often inconspicuous) ladybug feet and antennae, and the absence of obvious notches on the dorsal surface of the elytra also help distinguish them from other similar families.

However, some ladybugs are longer than twice their body width, such as the large spotted long-legged ladybug from North America.

Life characteristics: Ladybugs have different places of activity in different seasons. In winter, ladybugs overwinter among the rhizomes of wheat and rape, and some spend the winter in sunny clods and crevices.

In spring, once the temperature rises above 10, the overwintering ladybug wakes up and becomes active, finding it on wheat and rape plants.

In summer, as the temperature rises and the food increases, ladybugs multiply in large numbers, and ladybugs can be found on plants parasitic with aphids and scales, such as cotton, willows, locust trees, elms, beans and other plants, and sometimes even a large number of ladybugs gather.

In autumn, the number of ladybugs in the field decreases, and it often lays eggs in corn, turnips and cabbage, etc., at this time, the temperature is lower in the morning and evening, and the ladybugs are often hidden and difficult to find, so they need to be collected after 7 o'clock in the morning and before the sun goes down.

Introduction

The adult of the seven-star ladybug has a long lifespan and preys on the larvae and eggs of aphids, leaf mites, whiteflies, corn borers, and cotton bollworms with adults and larvae. The amount of food eaten by the seven-star ladybug is related to the temperature and prey density.

Under the condition of high temperature, the activity ability of the seven-star ladybug and prey is affected, and the predation rate is increased. It also has the ability to set up a set of death, and when it encounters strong enemies and dangers, it immediately falls from the tree to the ground.

Eggs: mm long; Width mm. Orange yellow packet, long ovate.

The main characteristics of each age stage: 1st instar: 2-3 mm in length.

The body is all black. From the midthoracic to the eighth abdominal segment, each segment has 6 tricholomatosis on each segment. Second instar:

Body length 4 mm. The head and feet are all black, and the body is grayish-black. The left and right posterior corners of the anterior chest are yellow.

There are 6 warts on the back and sides of each abdominal segment, and the 2 warts on the back and left of the first abdominal segment are yellow and black. The yellow spots on the dorsal surface of the fourth abdominal segment are inconspicuous. The rest of the warts are black.

Third instar: body length 7 mm. The body is grayish-black.

The head, feet, dorsal plate of the thorax and the distal plate of the abdomen and gluteal plate are black. Yellow spots on the anterior and posterior corners of the dorsal plate of the anterior thorax. The first left and right side of the abdomen and the lower side of the abdomen are orange and black.

The 2 warts on the dorsal side of the fourth segment are slightly yellowish, and the rest of the warts are black. Fourth instar: about 11 mm in length.

The body is grayish-black. Anterior and posterior corners of the dorsal plate of the prothorax have orange spots. The first and fourth segments of the abdomen have orange spots on the left and right sides of the abdomen and the inferior lateral warts.

The rest of the warts are black. Pupa: body length 7 mm, width 5 mm.

Body yellow. There are 4 black spots on the anterior edge of the dorsal plate of the prothorax, **2 of which are triangular, and 2 black spots on the posterior edge of the dorsal plate of the prothorax with 2 dark spots on both corners. There are 2 dark spots on the dorsal plate of the mesothoracic plate.

There are 4 dark spots on the dorsal side of the 2nd-6th abdominal segments. The end of the abdomen bears the black molt of the last instar larvae.

1. Seven-star ladybug.

Characteristics: The body is oval, the back is arched, and it is watery; head black, compound eyes black, with a yellowish spot on each medial concave; Antennae brown. The seven-star ladybug has to go through four different stages of development in its life: egg, larva, pupae and adult, and the development period of each insect state is mainly affected by food and temperature.

The seven-star ladybug is widely distributed in Africa, Europe, and Asia.

2. The lower jaw whiskers of the seven-star ladybug are its main tactile and olfactory organs. Seven-star ladybugs are often found in aphids.

When the lower jaw whiskers touch the aphid, it can quickly bite with the upper jaw and swallow the aphid. If the lower jaw whiskers are not touched, it seems impossible to detect the aphid, even if it is right in front of its eyes.

3. Although the adults and larvae of the seven-star ladybug feed on aphids, due to different insect states and different mouthparts structure, there are also differences in feeding methods. When adults feed, they usually bite the aphid, and after simple chewing with their mouthparts, they swallow the aphid's body and appendages completely. Older larvae feed in much the same way as adults.

4. However, due to their small mouthparts and poor swallowing power, the instar larvae often bite a hole in the aphid's body to suck the juice, and finally leave the aphid body shell. An adult of the seven-star ladybug eats an average of 100-120 cotton aphids, 147 vegetable aphids, and 59 apricot aphids a day. The amount of aphids eaten by larvae varies according to the size of the instar, with less snacks in the instar and more in the instar period.

1. Appearance, the wings of the seven-star ladybug have seven black dots.

2. Survivability, the seven-star ladybug has a strong self-defense ability. There is a "chemical**" on the joints of its 3 pairs of thin feet, and when it encounters an enemy attack, its foot joints can secrete an extremely unpleasant yellow liquid, making the enemy retreat and flee in a hurry because they can't stand it. It also has the ability to set up death, when it encounters strong enemies and dangers, it immediately falls from the tree to the ground, shrinks 3 pairs of thin feet under the stomach, pretends to be dead and lies down, hiding from the enemy and surviving.

3. The timid seven-star ladybug that has just been drilled out of the pupal shell stays motionless in the pupal shell. At this time, if you suddenly push it down with your fingers to scare it, after more than a day, the elytra of the seven-star ladybug gradually hardens, but the seven spots can never appear, becoming a "spotless" seven-star ladybug.

4. Hibernation, the overwintering seven-star ladybug does not eat or move, as long as it is found, it is very convenient to catch, and it can be caught by hand.

5. Eliminate pests. After the seven-star ladybug multiplies, it can be released into the field to help humans eradicate aphids and scales. If there is a large number of aphids in the cotton field, the seven-star ladybug can be scattered in the cotton field, and it can eat the aphids.

When distributing, put seven-star ladybugs while walking in the cotton field, and put a few in a few steps, in order to disperse evenly.

The morphological characteristics of the seven-star ladybug are: the body is oval, the back is arched, and it is half a water scoop. The head is black, the compound eyes are black, each with a yellowish spot on the medial concave, and the antennae are brown.

Mouthparts black. The upper extra side is yellow. The dorsal plate of the prothorax is black, and each of the anterior upper corners has a large, nearly square pale yellow ground.

Small shield black. elytra red or orange-yellow, with 7 dark spots on both sides; The base of the wings has 1 triangular white ground on each side of the small shield. The abdomen and feet are black.

There is 1 yellowish spot on each of the edges of the forehead and compound eyes. There are two yellowish dots between the compound eyes, sometimes connected to the macula mentioned above. Antennae chestnut-brown, slightly longer than the width of the forehead, hammer joints tight, lateral margins straight, terminal flattened.

There are narrow yellow stripes on the anterior edge of the labial base, the upper lip and mouthparts are black, and the outer part of the palate is yellow. The dorsal plate of the prothorax is black, with one yellowish spot on each of the two anterior horns that is nearly quadrangular.

Small shield black. The ventral process of the anterior thoracic plate is narrow and sunken, with a longitudinal line, and the posterior baseline branches. The feet are black, the tibia has 2 spine distances, and the claws have abutment teeth. The ventral surface is black, but the posterior side of the midthorax is white. The posterior margin of the sixth abdominal segment is convex and has a flat surface.

What are the characteristics of the seven-star ladybug? Why is it said to be a beneficial insect and is called a live pesticide.

There is also a wonderful habit among ladybugs: beneficial insects and pests have a clear boundary between each other, do not interfere with each other, do not intermarry with each other, and maintain their traditional habits, so that no matter how many generations they have passed down, they will not produce "mixed breeds", nor will they change their traditional habits.