Subtype Tracheal Breathing Class Insects and Class Reptiles
1. The body is covered with scales, cold-blooded, lay large coated eggs (occasionally viviparous). The influence of reptiles on our agriculture is insignificant.
Lizards, exterminating insects, are certainly useful. The water snake, which differs from the usual one by the absence of yellow semi-lunar spots on its head and a lighter overall color, turns out to be a serious pest of pond fish farming in the south of the country. Multiplying in large quantities at outgrowth ponds, the water snake eats fish fry in bulk.
In the south of Kazakhstan and everywhere in the plains of Central Asia, the Central Asian or steppe turtle is found. In the spring, waking up from hibernation, turtles pounce on fresh greenery. Melon seedlings are especially loved, as well as young leaves of wheat and cotton. In the fields with these crops, they accumulate up to 20 individuals per hectare. Soon they lay about 15 eggs in three steps, each with a diameter of up to 5 centimeters, digging them into the ground. The turtles will hatch in August, but they will appear on the surface only in the spring of next year. Turtles are active no more than three or four months a year. Already in June, when the vegetation burns out, they hibernate. Therefore, they live long and grow slowly. The maximum dimensions (the diameter of the shell is up to 20 centimeters with a body weight of up to two kilograms) are achieved in 20-30 years of life. Turtles also harm with their burrowing activities. When they dig their burrows for wintering, they destroy the walls of irrigation canals and dams. In some places, in order to reduce the harm they cause, turtles are caught. And as a delicatessen meat, always in demand in rich restaurants, is exported. Methods of breeding Central Asian turtles have been developed, but farms are not yet economical. The wards sleep more than they eat and grow.
2. In representatives of the subtype, which, in addition to insects, includes millipedes, respiration is either cutaneous (in lower forms), or carried out through the trachea. Trachea — thin tubes extending into the body, reinforced from the inside with a chitinous spiral. The name of the subtype is not entirely successful — after all, tracheae of the same device are found in another subtype, in spiders and ticks, that in the subtype of chelicerae. Perhaps the most characteristic feature of our subtype is one pair of antennae on the head (crustaceans have two pairs of them, chelicerae do not have at all). Since there are no species among millipedes that have any significant impact on the branches of agriculture, let's move on to insects. The insect class exceeds all other animals combined in terms of the number of species included in it (about 2 million). It is not yet clear why, it was the construction of a "tracheal-breathing" head (a pair of antennae and three pairs of jaws), three segments of the chest (each with a pair of legs) and a legless abdomen that turned out to be particularly successful and was replicated by nature in the greatest variety of options with the obligatory preservation of the mentioned features. This was probably especially facilitated by the wings in the number of one or two pairs belonging to the thoracic segments. Insects are mainly terrestrial animals, among them there are a lot of species useful or harmful to agricultural production. The science of entomology studies insects. The department of insects with incomplete transformation consists of species in which the larva that has emerged from the egg has the same division of the body and limbs as in adults; there is no resting stage of the pupa. skylines.ru
Lizards, exterminating insects, are certainly useful. The water snake, which differs from the usual one by the absence of yellow semi-lunar spots on its head and a lighter overall color, turns out to be a serious pest of pond fish farming in the south of the country. Multiplying in large quantities at outgrowth ponds, the water snake eats fish fry in bulk.
In the south of Kazakhstan and everywhere in the plains of Central Asia, the Central Asian or steppe turtle is found. In the spring, waking up from hibernation, turtles pounce on fresh greenery. Melon seedlings are especially loved, as well as young leaves of wheat and cotton. In the fields with these crops, they accumulate up to 20 individuals per hectare. Soon they lay about 15 eggs in three steps, each with a diameter of up to 5 centimeters, digging them into the ground. The turtles will hatch in August, but they will appear on the surface only in the spring of next year. Turtles are active no more than three or four months a year. Already in June, when the vegetation burns out, they hibernate. Therefore, they live long and grow slowly. The maximum dimensions (the diameter of the shell is up to 20 centimeters with a body weight of up to two kilograms) are achieved in 20-30 years of life. Turtles also harm with their burrowing activities. When they dig their burrows for wintering, they destroy the walls of irrigation canals and dams. In some places, in order to reduce the harm they cause, turtles are caught. And as a delicatessen meat, always in demand in rich restaurants, is exported. Methods of breeding Central Asian turtles have been developed, but farms are not yet economical. The wards sleep more than they eat and grow.
2. In representatives of the subtype, which, in addition to insects, includes millipedes, respiration is either cutaneous (in lower forms), or carried out through the trachea. Trachea — thin tubes extending into the body, reinforced from the inside with a chitinous spiral. The name of the subtype is not entirely successful — after all, tracheae of the same device are found in another subtype, in spiders and ticks, that in the subtype of chelicerae. Perhaps the most characteristic feature of our subtype is one pair of antennae on the head (crustaceans have two pairs of them, chelicerae do not have at all). Since there are no species among millipedes that have any significant impact on the branches of agriculture, let's move on to insects. The insect class exceeds all other animals combined in terms of the number of species included in it (about 2 million). It is not yet clear why, it was the construction of a "tracheal-breathing" head (a pair of antennae and three pairs of jaws), three segments of the chest (each with a pair of legs) and a legless abdomen that turned out to be particularly successful and was replicated by nature in the greatest variety of options with the obligatory preservation of the mentioned features. This was probably especially facilitated by the wings in the number of one or two pairs belonging to the thoracic segments. Insects are mainly terrestrial animals, among them there are a lot of species useful or harmful to agricultural production. The science of entomology studies insects. The department of insects with incomplete transformation consists of species in which the larva that has emerged from the egg has the same division of the body and limbs as in adults; there is no resting stage of the pupa. skylines.ru
