The work was done by Yuliya Serova
student 7 E.
Teacher Bondarev G.V.
MOU Lyceum №9. Volgograd 2014.
Lepidoptera – a detachment of insects with complete metamorphosis, the most characteristic feature of whose representatives is the presence of a dense cover of chitinous scales on the front and hind wings.
Development with complete transformation: there are egg, larva (called caterpillar), pupa and adult stages. The larva is worm-like, with underdeveloped ventral legs, powerfully sclerotized integuments of the head, gnawing mouthparts and paired silk secreting glands, the secretions from which, when in contact with air, form a silk thread.
In the breeding biology of butterflies, the color and shape of the wings (attracting partners), as well as complex forms of courtship (nuptial flights and dances), play an important role. Some species are characterized by sexual dimorphism, which plays an important role in the normal course of the sexual cycle, since external differences make it easier to identify and find a mate of their species. Pheromones produced by male club butterflies and females of nocturnal species also contribute to the search for each other by partners. Many male club butterflies have odorous scales – androconia, which are located on the wings, less often on the legs. In whites, androconia are located almost over the entire surface of the wings. In other species, they are concentrated on certain parts of the body, and often form special velvety spots or stripes on the wings.
The organs that secrete pheromones in females are located at the posterior end of the abdomen between segments 8 and 9, and in a number of species they can extend outwards.
Saturnian males can find a female by pheromones at a distance
several kilometers. Mating takes place on the ground or
tenia and lasts from 20 minutes to several hours; all this time
mating individuals remain motionless. During mating-
the female receives from the male not only spermatozoa, but also a number of
some proteins and trace elements necessary for the formation
niya and laying eggs.
Parthenogenesis is extremely rare in butterflies, observed in bagworms, moths of the genus Solenobia , as an exception – in some silkworms (silkworm).
Butterflies are insects with complete transformation, or holometamorphosis. Their life cycle includes four phases:
adult insect (imago).
Butterfly eggs are covered with a dense hard shell and can be of various shapes. They can be round, cylindrical, spherical, ovoid, angular. Their surface can be embossed, forming depressions, dots, stripes, tubercles .. The color is most often white and greenish, less often –
brown, yellow, red, blue, dark green. The females lay
yut eggs on the leaves, stems or branches of fodder plants. Their number in
masonry depends on the species and can be more than 1000, however, up to adult
Few survive at this stage. Depending on the species, the eggs may
deposited singly or in groups of 10 or more. Females can cover the eggs with hairs from a dense tuft at the end of the abdomen. Also, laid eggs can be covered with secretions of the accessory sex glands, which, when solidified, form a protective shield (apple moth).
The caterpillar is the larva of a butterfly. She is usually worm-like,
with chewing mouthparts. Most caterpillars are
phytophages – feed on leaves, flowers and fruits of plants.
Caterpillars distinguish three main groups of digestive
enzymes – proteases, carbohydrases and lipases.
The body of a caterpillar consists of 3 thoracic and 10 abdominal segments. Leather
smooth, with sparse warts, setae or hairs, spines. The thoracic segments bear 3 pairs of jointed legs, the abdominal segments usually have 5 pairs of thicker legs, with hooks on the soles, which help the caterpillar to stay on the substrate.
The shape of the pupa is from an elongated cylindrical, ovoid to almost round. Coloring, monophonic from light to dark or with a different pattern of dots, spots and stripes. Immediately after pupation, the color is often pale, sometimes almost white or
greenish, then it changes to the characteristic of this species, and
the peg turns, for example, from green to brown.
She clearly distinguishes the outlines of the rudiments of wings, proboscis and legs,
abdomen with spiracles on the sides, cremaster at the end of the abdomen – special
social thickening, often forked at the apex, with hooks
for fastening with cobweb threads to the substrate.
Sometimes it is located openly on the plant, but more often it is located inside braided, folded and glued leaves, or in the surface layer of the soil, on the stems and trunks of plants. The pupa is more often attached to the substrate (there are hanging pupae and girdled ones), less often it lies freely on the litter or on the ground among plant remains in a sparse cobweb. The hanging pupa is attached with its head end down with the help of a cremaster, while the girdled pupa is attached with its head up; in addition to the cremaster, it is supported in this position by a special cobweb belt.
The pupae do not feed. In some species, the pupa is the stage that enters winter diapause.
An adult insect emerges from the pupa – imago. Approximately a day before the release of the butterfly, the pupa shell becomes oily-transparent. Then the pupa breaks along the head and the anterior edge of the wings, and the adult, clinging to the edge of the torn shell with its feet, crawls out. In many groups of Lepidoptera, males emerge from pupae before females, so at the beginning of the butterfly flight period, only males are found, and at the end, only females.
In the first minutes after leaving the chrysalis, the butterfly is not yet able to fly. It climbs vertical elevations, where it remains until the wings spread, which occurs under the action of the hydrostatic pressure of the hemolymph. Spread wings harden and take on the final color.
Imago is a sexually mature form capable of reproduction. The main function of this stage of the life cycle is reproduction and resettlement.
The lifespan of adults ranges from several hours to several months (in diapause species) and averages 2-3 weeks.