okr the world of insects from the eggs appear. Reproduction of insects. Complete and incomplete transformation of insects
To produce offspring, most insects need to mate with an individual of the opposite sex. Through instinctive reactions to specific smells, colors and sounds, the insect finds a suitable partner. This mechanism works in the dark, in dense thickets and over long distances. Fireflies familiar to us do this: wingless females attract males on warm spring evenings with the help of light signals. Other insects give sound "marriage" signals: for example, crickets and grasshoppers charm their partners with their chirping.
Where do insects lay their eggs?
Insect eggs, as a rule, are covered with a strong shell. The stick insect simply leaves them on the ground or rolls them in front of him. However, most females look for a place for their eggs that is protected from wind and enemies. The insect instinctively feels in what environment the offspring after hatching will find themselves in favorable conditions and receive the necessary food. Crickets and grasshoppers dig holes in the ground where they place their eggs. Female mosquitoes leave their eggs on the surface of the water. Butterflies and other insects whose larvae are herbivores lay their eggs on plants.
Dung beetles dig mammal dung into the ground. Many of the 7,000 species of sawfly make balls out of manure by rolling it off the manure heap and burying it in a safe place. They feed on these balls themselves, and also supply their offspring with “pills”. To this end, they make a hole in the ball and lay eggs there. The hatched larva feeds on such a ball.
Grasshoppers and ichneumons have a long ovipositor with which they pierce the soil and lay their eggs there.
growths
Some species of wasps lay their eggs on oak trees and rose leaves. Gradually they are covered with plant tissue. The hatched larvae feed on the creatures inside the growth, grow and pupate. Some species of mosquitoes, flies, aphids, beetles and butterflies also use plants as a "host", breeding offspring. In order for outgrowths to form, the plant tissue must have the ability to grow at the time the insect eggs are deposited.
How do insects take care of their offspring?
Some species of insects take care not only of a suitable place for hatching offspring. Cockroaches often carry eggs with them in a kind of "bag" on the back of their torso. In some species of water bugs, the female lays her eggs on the back of the male. He carries the eggs with him, providing enough oxygen and protecting him from the fungus. The gravediggers jointly bury a dead mouse or other small animal, raking the ground under the animal's corpse and moving it to the very end of the "cave". There they lay their eggs, and the female (and sometimes both partners) remains to look after the offspring, feeding the larvae with parts of a dead animal. The care of the offspring of termites, ants and bees and wasps living in colonies is interesting: the offspring remain in the nest until they grow up. Workers do not reproduce, returning to their nest throughout their lives.
Birch bug females guard their eggs. Protecting them, they turn their backs on their enemies.
Complete and incomplete transformation of insects
Incomplete transformation of insects
Larvae of cockroaches and grasshoppers, having barely emerged from the egg, already look like adult insects of their species. They are only smaller than them, and they have not yet developed wings and reproductive organs. During growth, these insects do not change so much. In this case, one speaks of an incomplete transformation. The nymph insect that emerged from the egg is very similar to the adult insect; nymphs are called larvae that undergo incomplete transformation. In young mayflies and dragonflies, the wings are barely visible, but with each change of shell they become more noticeable.
Complete transformation of insects
The insect develops from an egg, then several caterpillar stages follow, which turns into a chrysalis; then an adult insect hatches from it, thus passing through many stages of transformation. More than four-fifths of all insects develop through the pupal stage. Such a transformation is called complete. Butterfly pupae are completely different from their parents. In addition to three pairs of legs on the chest, like an adult butterfly, the pupa has five more pairs of legs, with the help of which it moves and holds firmly. The larvae of beetles, flies and bees are also completely different from adult insects. At the end of the larval stage, the insect changes significantly: it no longer takes food, seeks shelter and passes into the next stage: it pupates. Butterfly pupae spin a cocoon from long silk threads produced with the help of one of their glands. The pupa seems immobile only from the outside: inside it, significant transformations of the organs of the larva into the organs of an adult insect take place. The intestines, the tracheal system, the nervous system and the pectoral muscles are especially modified. A flying insect that feeds on nectar grows from a herbivorous wingless creature. Depending on the type of insect and environmental conditions, it emerges from the cocoon in a few days, weeks or months.
The life cycle of butterflies consists of four stages: egg, larva, pupa and adult. Butterflies are insects with a so-called full cycle of transformations, since the larva is completely different from the adult. The transition from one stage to another, or transformation, is called metamorphosis.
testicles This is the first phase of insect development. The testicles must be kept intact, so the butterflies take care of this, some lay them in the soil, others fill the testicles with secretions of glands that harden in the air - a capsule is obtained, the capsules are usually masked to match the color of the surface. Another way is that insects cover the testicles with hairs or scales that are scraped from the abdomen. The female lays her eggs in batches, which can contain a few eggs, and can reach hundreds of eggs. Depending on the species, they are arranged in layers, in a line or in a ring around the shoot of the plant that the caterpillars will feed on. In some species, the female disperses the eggs in flight. The development of the embryo depends on climatic conditions and can last from several days to several months, especially when the insect hibernates at the egg stage.
Emerge from testicles larvae - caterpillars. They actively feed, grow and accumulate substances for the following transformations. The caterpillar has three pairs of jointed legs, armed with claws, and several (up to 5 pairs) false legs, equipped with bundles of claws, which allows it to stay well on the support. Caterpillars of diurnal butterflies are very diverse in color and external structure. They have gnawing mouthparts and, for the most part, feed on the leaves of various plants. Caterpillars are growing fast. Gradually, the outer covers (cuticles) of the larvae become too tight for her, and they need to be changed. There is a molt, which is preceded by a period of growth. Most larvae have 5 or even more if the larva hibernates. Therefore, the life span of the larvae can reach from several weeks to several months, and for carpenters up to 2-3 years.
At the last molt, the caterpillar turns into chrysalis. The color and shape of the body of butterfly pupae is no less diverse than that of caterpillars. Butterfly pupae do not feed and do not move, they are usually attached to branches, leaves, various objects (the so-called "belted" and "hanging" pupae), or lie freely on the soil - among fallen leaves and in the soil litter. The duration of the pupal stage can vary from a few weeks (in some tropical species) to nine months or more (in temperate climates where winters are long). During this period, organs and tissues change and acquire features characteristic of adults, wings and muscles are formed.
A butterfly emerges from the chrysalis. adult butterfly (imago) quickly reaches sexual maturity and in a few days is ready for reproduction. Depending on how quickly the butterfly fulfills this main purpose, it lives from several days to several weeks. The exception is wintering butterflies, which can live for more than 10 months.
Insects with incomplete metamorphosis
In a cockroach, as in representatives of some other orders of insects ( Mayflies, Dragonflies, Praying Mantises, Stoneflies, Orthoptera, Earwigs, Lice, Homoptera), development takes place with incomplete conversion . This means that larvae appear from the eggs - small insects that look very similar to their parents. They differ from adult insects in their smaller size, lack of wings and underdevelopment of the reproductive system. The larvae molt several times, grow with each molt and become more and more like adult insects. Over time, they become sexually mature, and their wings are fully formed. After that, the insects no longer grow.
Thus, an insect with incomplete transformation goes through three stages in its development: egg -> larva -> adult insect (Fig. 101).
Dragonflies. A detachment of well-known insects with a long slender body and two pairs of strong transparent wings (Fig. 102, 1 ). Dragonflies (especially large ones) are distinguished by very fast and maneuverable flight. They are predators, catching insects (flies, mosquitoes, small butterflies) on the fly. Dragonflies have large compound eyes that provide an almost all-round view, and long legs covered with stiff hairs. Dragonfly larvae are inactive, live in ponds, lakes, ditches with water, slowly flowing rivers. They are also predators and grab crustaceans passing by, larvae of other insects, tadpoles and fish fry with the help of a lower lip that can be thrown forward, which is called mask .
Orthoptera. This group includes locusts, grasshoppers(Fig. 102, 3 ), crickets and bears. They have two pairs of wings (the front ones are denser than the hind ones), many of the hind limbs are jumping, and the mouthparts are gnawing. Many of the Orthoptera jump up to 80 cm high, and if they help themselves with wings, then the distance covered by them in one jump reaches 10 m. Some species of locust fly well. Locusts feed on plants, grasshoppers are both herbivores and predators, and crickets are omnivores.
Homoptera. To this group belong cicadas(Fig. 102, 6 ) and aphids. Their mouth apparatus is of a piercing-sucking type, and the wings are usually folded into a roof. Homoptera feed on plant sap. Cicadas are rather large (up to 7 cm long) diurnal insects and are known for being able to make very loud sounds with the help of special organs located at the base of the abdomen. Aphids are small insects a few millimeters long. Among them there are both winged and wingless forms.
bedbugs, or Hemiptera. The insects of this order are so called because their front wings (elytra) are dense in front and soft in the back (Fig. 102, 2 ). The second pair of wings lies under the first. It is with the help of the second pair of wings that bed bugs can fly. Some, for example, bed bug, wings are missing. The mouthparts of bedbugs are piercing-sucking. Among the bugs there are species that feed on plant sap, there are predators and bloodsuckers (bed bugs).
Insects with full metamorphosis
In insects with complete metamorphosis, the larvae do not look like adults at all. These are the larvae butterflies, beetles, flies, wasps, ants. These larvae lack compound eyes, only simple ocelli, or organs of vision are completely absent; the body is most often worm-shaped (butterfly caterpillars). Often there are no antennae, no wings. Insect larvae with complete metamorphosis molt several times and grow. Having reached the maximum size, the larva turns into chrysalis - this is another stage of development, usually immobile, intermediate between the larva and the adult insect.
Thus, insects with complete transformation go through four stages in their development: egg -> larva -> chrysalis -> adult insect (Fig. 103).
In insects with complete metamorphosis, the larvae often live in completely different places and feed on different foods than adult animals. So, caterpillars (butterfly larvae) feed on the green parts of plants, their mouthparts are gnawing. Adult butterflies feed on the nectar of flowers, and their mouthparts are sucking. Midges suck the blood of mammals, and their larvae live in the running water of rivers and catch small organic particles carried by the current. Differences in habitats and nutrition of insects at different stages of development with complete metamorphosis exclude competition between larvae and adults of the same species.
Most insect species are characterized by development with complete transformation.
butterflies, or Lepidoptera(Fig. 104, BUT). The insects of this order are so named because they have very small chitinous scales on their wings. They are variously colored and strongly refract the incident light. Therefore, the wings of butterflies have bizarre and bright colors. The coloration of butterflies' wings helps them to recognize each other, camouflages them in the grass and on the bark of trees, or warns enemies that the butterfly is inedible. The mouth apparatus of butterflies is sucking - it is a proboscis coiled into a spiral. Butterflies feed on the nectar of flowers. When pupating, the caterpillars of some butterflies secrete silk threads. Threads mulberry and oak silkworm man uses to obtain silk fabrics.
beetles, or Coleoptera(Fig. 104, B). Representatives of this order have dense hard elytra covering the second pair of leathery wings with which they fly. The oral apparatus is gnawing. Among the beetles, there are many herbivores. There are predators that prey on other insects, and scavengers. Beetles live in the ground-air environment (on plants, the surface of the earth, in the soil) and in water. Beetle larvae are both very mobile predators living openly, and inactive, similar to worms, living in shelters and feeding on plants, fungi, and sometimes decaying remains of organisms.
Diptera(Fig. 104, AT). These insects have only one pair of wings. The second pair is greatly reduced and serves to stabilize the flight. This group includes mosquitoes and flies. Some Diptera have licking mouthparts, while others have a piercing-sucking mouthpart. Diptera feed on pollen and nectar of flowers (syrphid flies), predators (ktyri) and bloodsuckers (mosquitoes, midges, midges, horseflies). Their larvae live in the decaying remains of cesspools, composts (house flies), in water (mosquitoes and midges) or lead a vagrant lifestyle and prey on small insects.
Hymenoptera(Fig. 104, G). The order includes such well-known insects as bumblebees, wasps, bees, ants. Representatives of this order have two pairs of membranous wings, but some have no wings. This group includes sawflies. They are called so because the females have a serrated ovipositor resembling a saw. With this ovipositor, the females cut the leaves and stems of plants, and then lay their eggs there. Sawfly larvae are similar to butterfly caterpillars. The hymenoptera include riders. Their females, using a long ovipositor, pierce the covers of caterpillars and lay eggs in them. The larvae that emerge from the eggs eat the caterpillars.
Incomplete transformation: egg -> larva -> adult insect (orders Dragonflies, Orthoptera, Homoptera, Bedbugs); full transformation: egg -> larva ->chrysalis -> adult insect (orders Lepidoptera, Coleoptera, Diptera, Hymenoptera).
Development and
reproduction
animals
Prepared by: primary school teacher
MBOU "Shock secondary school" Medvedeva V.M.
Domestics caress, and wild ones bite.
They are everywhere and everywhere:
on land, in the sky and in the water,
there are forest ones, marsh ones.
We call them...
ANIMALS
There are a lot of animals in nature, all of them
different, but they can be divided into several groups
according to common characteristics and habitat.
insects
fish
amphibians
reptiles
birds
mammals
fish reptiles insects amphibians mammals birds
Guess who it is?
I grow like a worm.
I eat leaves
Then I fall asleep
I wrap myself
I don't eat, I don't look
I hang motionless
But warm spring
I come alive again
And I flutter like a bird.
BUTTERFLY
Insects
Development
butterflies
The nettle butterfly lays its eggs on nettles.
The eggs hatch into larvae. Butterfly larvae are called
caterpillars. They don't look like adult butterflies at all.
Caterpillars feed on nettle leaves, grow rapidly, and
then turn into motionless pupae.
A little time will pass, and from each chrysalis will appear
butterfly.
ya
eggs
egg
caterpillar
gugu
larva
chrysalis
pupae
a
butterfly
adult
insect
It is interesting
The caterpillar grows so fast that its skin
cracking, and under it there is already a brand new skin,
designed for growth.
- In her entire life, a female butterfly lays 50
000 eggs.
- Butterfly does not grow, however it does from time to time
likes to drink sweet flower nectar. This is
fuel that helps it fly.
In the meadows and on the edge,
In the midst of green grass
Disguised skillfully
Long-haired cheerful!
his chirping,
Often cuts ears
He doesn't trust anyone
Do you want no? BUT
listen!
Legs are long
shoulders,
Well! Learned? He...
GRASSHOPPER
Grasshopper development
Not all insects can have pupae.
Grasshoppers do not have pupae. Their larvae are very
similar to adult grasshoppers, only quite
small and do not have wings. growing up
each larva sheds several times
skin. When is the last time this happens
the skins come out already an adult insect-large
and with wings.
larva
egg
adult
insect
Swimming under the bridge
And I wag my tail.
I don't walk on earth
I have a mouth, but I don’t say
I have eyes - I do not blink,
I have wings - I can't fly.
Fish development
In spring, the females spawn into the water.
From the eggs, fry appear that look like adults
fish,
only very small ones.
The fry feed, grow and become adult fish.
caviar
fry
fish
Interesting Facts
The blue whale is the largest animal on the planet. Maybe
reach a length of 33 m and a mass of 150 tons. Cubs
are born with a length of 6 to 8.8 m and a weight of 2-3 tons. Blue
whales are found in almost all areas
World Ocean.
Amphibians and reptiles
Paws come out of the fry -
Long guys.
A frog is jumping in a puddle -
Leggy…
frog development
In spring, loud voices are heard in a pond, river, lake
frogs and toads - real concerts! Female frogs and toads
lay eggs in the water.
After a few days, tadpoles come out of the eggs,
which look like small fish than adults
amphibians.
Tadpoles live in water, feed, grow and
turn into
frogs and toads.
caviar
tadpoles
frog
Female lizards, snakes, turtles, crocodiles lay eggs.
Eggs hatch into small lizards, snakes, turtles,
crocodiles. They grow and gradually turn into
adult animals.
Reproduction and development
eggs
cubs
adult
animal
Birds
Almost all birds build nests in spring. Into the bird's nest
lay eggs and incubate them - they warm with their warmth.
Chicks grow fast and need a lot of food.
In late spring and early summer, the chicks of many birds leave their nests.
Although they are already covered with feathers, they still fly poorly. eat
they can't do it on their own either. Parents for a while
feed their chicks and protect them from enemies.
Reproduction and development
eggs
chicks
adult bird
It is interesting
The cuckoo doesn't build its nest or incubate its eggs,
which
she took it down. And puts them in the nests of other birds, as
chanter rule.
Sometimes the cuckoo manages to smash into other people's nests up to 20
their eggs.
The cuckoo tries to push
from the nest other eggs and even small chicks, so that he
got more food. Soon a little gluttonous
cuckoo
there are more of their adoptive parents who
exhausted to feed the foundling.
Domestics caress, and wild ones bite.
They are everywhere and everywhere:
on land, in the sky and in the water,
there are forest ones, marsh ones.
We call them...
ANIMALS
There are a lot of animals in nature, they are all different, but they can be divided into several groups according to common characteristics and habitat.
insects
amphibians
mammals
reptiles
Guess who it is?
I grow like a worm. I eat a leaf, Then I fall asleep, I wrap myself around, I don’t eat, I don’t look, I hang motionless, But in the warm spring I come to life again And, like a bird, I flutter.
Insects
Butterfly development
Butterfly-urticaria lays eggs on nettles.
From the eggs hatch larvae. Butterfly larvae are called caterpillars. They don't look like adult butterflies at all.
Caterpillars feed on nettle leaves, grow rapidly, and then turn into motionless pupae .
A little time will pass, and from each chrysalis will appear butterfly .
caterpillar
adult insect
It is interesting
Caterpillar grows so fast that her skin is cracking, and under her there is already a brand new skin designed to grow.
For all my life female butterfly lays 50,000 eggs.
- Butterfly does not grow, however, she likes to drink sweet flower nectar from time to time. It's the fuel that helps it fly.
Butterflies are born to die, giving life to a new generation. Most of them live only a few days, with the exception of the Monarch butterfly, which can live up to six months.
In her short life, a female butterfly can lay over 1,000 eggs.
The largest moth in the world is the Atlas peacock-eye (Attacus Atlas). Its wingspan is over 30 cm and it is often mistaken for a bird.
In the blue butterfly (Zizula hylax), which lives in Africa, Madagascar, Mauritius, Arabia and the tropical zone of Asia and Australia, the length of the front wing is 6 mm.
In the meadows and on the edge, Amid the green grass, The long-whiskered, cheerful, skillfully disguises himself! His chirping, Often cuts his ears, He does not trust anyone - Do you want it, no? And listen! Legs - long on the shoulders, Well! Learned? He...
GRASSHOPPER
Grasshopper development
Not all insects can have pupae. Grasshoppers do not have pupae. Their larvae are very similar to adult grasshoppers, only they are very small and do not have wings. Growing up, each larva sheds its skin several times. When this happens for the last time, an adult insect comes out of the skin - large and with wings.
adult insect
I swim under the bridge And wag my tail. I don’t walk on the ground, I have a mouth, but I don’t speak, I have eyes - I don’t blink, I have wings - I don’t fly.
Fish development
In spring, females sweep into the water caviar .
From the caviar appear fry, which look like adult fish,
only very small ones.
The fry feed, grow and become adult fish.
It is interesting
Electric fish. Did you know that some fish can shock underwater?
For example, the electric eel from South America, which
sometimes grows up to three meters long! Its electric
the discharge is very dangerous and can stun even a horse. Although,
of course, usually the eel attacks frogs and fish, which
feeds than on larger creatures. But in case
danger to a person can attack a person. By the way,
electric catfish lives in Africa, which is at least 2 times
and less eel, but also deadly.
Fish have been on Earth over 450 million years ago. They are
appeared before dinosaurs.
flying fish
There are about 40 species of flying fish. The fish is accelerating
under water and jumps up actively waving its tail.
The large lateral fins of flying fish allow them to
fly over water up to 400 meters. This skill is volatile
fish are used to escape from predators. volatile diet
fish consists mainly of small crustaceans and
plankton.
Paws come out of the fry - Long-legged children. A frog is jumping in a puddle - Long-legged ...
Amphibians and reptiles
frog development
In the spring, in a pond, river, lake, the loud voices of frogs and toads are heard - real concerts! Female frogs and toads lay in the water caviar .
After a few days, the eggs come out tadpoles ,
which look like small fish than adult amphibians.
Tadpoles live in water, feed, grow and turn into
frogs and toads .
tadpoles
Female lizards, snakes, turtles, crocodiles lay eggs.
Small lizards, snakes, turtles, crocodiles hatch from eggs. They grow and gradually turn into adult animals.
Reproduction and development
adult
animal
cubs
Almost all birds build nests in spring. Birds lay eggs in the nests and incubate them - they warm them with their warmth. Chicks grow fast and need a lot of food.
In late spring and early summer, the chicks of many birds leave their nests. Although they are already covered with feathers, they still fly poorly. They are also unable to eat on their own. Parents feed their chicks for some time and protect them from enemies.
Reproduction and development
adult bird
It is interesting
The cuckoo does not build its nest and incubate eggs that
she took it down. And puts them in the nests of other birds, as
chanter rule.
Sometimes the cuckoo manages to spread up to 20 of its eggs in other people's nests.
The cuckoo tries to push
from the nest other eggs and even small chicks, so that he
got more food. Soon the little gluttonous cuckoo
there are more of their adoptive parents who
exhausted to feed the foundling.
Beasts
Animals, or mammals, give birth to young and feed with milk. In most mammals, babies are born in the spring. With a fox, they live in a hole, with a squirrel, in a hollow or in a nest in a tree, with a beaver, in a house-hut. Foxes and squirrels are born blind and helpless. But beavers are born sighted. Most animals take care of their offspring.
Reproduction and development
adult animal
Interesting Facts
The blue whale is the largest animal on the planet. It can reach a length of 33 m and a mass of 150 tons. Cubs are born with a length of 6 to 8.8 m and a weight of 2-3 tons. Blue whales are found in almost all areas of the oceans.
Since whales are mammals, their cubs, like the cubs of other animals of this class, are fed with mother's milk. They do not hatch from eggs like fish, but are born alive and stay with their mother for some time after birth.
Whales do not have gills, they breathe with lungs. Their tail fin is located horizontally and helps them to easily rise to the surface of the water when they need to breathe.
A newborn baby elephant weighs 90-120 kg with a shoulder height of about 1 m, his trunk is short, there are no tusks. 15-30 minutes after birth, the baby elephant rises to its feet and can follow its mother. Until the age of 4, he needs maternal care.
It is interesting
Fill in the missing words
Insects develop _________ eggs from eggs, and ________ in birds.
Caterpillars feed on _________ and then turn into
in motionless _________.
In fish, _________ is hatched from eggs, and in frogs and toads -
Animals give birth to ___________ and feed them _________
leaves
tadpoles