The housefly (in Latin the name of the insect sounds like Musca domestica) is considered the most common among the numerous representatives of the class.
Fly sitting on a flower
In zoology, it is customary to distinguish two types of winged insects: typical and southern houseflies.
The latter is distinguished from the indoor subspecies by its larger size. Let's consider the structural features of the housefly, how the wings and mouthparts of the insect are arranged
Distinctive features of the house fly
House flies have several distinctive characteristics that allow them to be recognized among other subspecies.
The body of the insect is in most cases gray in color. The lower segment of the head received a yellow color.
The upper part of the chest is decorated with four black stripes. Black spots of regular quadrangular shape are visible on the abdomen.
Its lower part has a slight yellowish tint. The insect's body size reaches six to eight millimeters.
Differences between males and females
How a mosquito works depends on its gender. There are differences in the external and internal structure.
Female and male mosquito
- The mustaches of females are long and elongated; in males they are covered with thick flagella and have the shape of brushes.
- Females have a more rounded abdomen and a darker color. Larger body size.
- Males have more developed hearing, which makes it easy to detect the squeak of a female. In females, sensory abilities predominate, helping to determine the location of the victim.
- The mouth of males is limited to elongated lips, a tube for absorbing nectar. The trunk lacks teeth and barbed needles.
The male feeds on flower nectar and pollen and spends most of its life in vegetation. Females hunt animals and people, so they often catch the eye of humans.
Features of the structure of the house fly
The main difference between the housefly and other relatives is the presence of only one pair of wings.
During the evolution of the insect, the second posterior pair turned into haltere appendages used to maintain balance.
In addition, the insect, despite the complex structure of the eye, is blind. The visibility limit is limited to a distance of 40 - 70 cm.
External structure
The skeletal structure of the housefly is no different from other classes of insects.
Represented by the head, chest and abdomen. The head is equipped with mouthparts, eyes and antennae.
Appearance of a housefly
The chest has a segmental structure - there are three of them. There are two wings, they are completely transparent. Legs - three pairs.
Well-developed muscles are located in the chest cavity. Inside the abdomen are located the main part of the digestive organs and the entire reproductive system.
Breast
The chest is represented by three interconnected segments. The prothorax, midthorax and metathorax are distinguished.
The insect gains the ability to fly due to its powerful muscles, so the middle segment is the most developed.
The body is equipped with three pairs of legs, each of which is divided into five interconnected particles. The paws have well-developed muscles.
At the tips of the paws there are miniature claws and suction cups, with the help of which the insect is able to attach and hold on to any surface.
Housefly foot under a microscope
Thanks to this, houseflies have the ability to move upward with their abdomen. During movement, a sticky secretion is released from the pads as a result of compression.
This feature helps the fly to hold firmly on the glass and absolutely smooth surface.
The housefly's legs serve as olfactory organs. Thanks to the villi receptors located on them, the insect will determine whether food is edible or inedible.
Head
The structure of a fly's head is simple. On its surface are the organs of vision, hearing and nutrition.
The mouthparts of a fly - the structure depends on the type of food the insect eats - is represented by a proboscis of a licking or sucking format.
The lips, represented by the lower and upper blades, come into direct contact with the food mass.
Housefly mouthparts
A large number of channels through which food enters the digestive system converge in the food proboscis of the fly.
The fly has a powerful jaw apparatus. The mouthparts of the fly, whose diet is based on blood, have sharp and hard scales.
This is a kind of imitation of teeth that help the fly damage the surface of human skin. The pump located in the pharynx is responsible for drawing in liquid and liquefied food.
You can also read our article: What do flies eat at home?
Most of the surface of the head is occupied by the eyes, which have a very complex structure. They are composed of a large number of simple eyes.
Visually – when zoomed in significantly – it looks like a faceted mesh.
Eyes of a fly
This structure provides the housefly with a comprehensive image of objects, but the overall picture is perceived as a mosaic.
The total number of simple eyes of a housefly reaches 4 thousand. The insect is able to instantly react to any movement, but it does not receive a full-fledged three-dimensional image.
The antennae are used by insects as landmarks. They help in perceiving different smells and determining the direction of flight and movement. They have characteristic differences in females and males.
Wings
The structure of a fly's wing is simple. The insect has one pair of wings. They are well developed, completely transparent, and have membranes.
The strength of the wing is ensured by the cylindrical veins running through it. The posterior pair was transformed into haltere appendages during evolution. Wings help the fly maintain balance during flight.
Housefly wings
In addition, they allow you to hover in the air if necessary. During the flight they emit a characteristic buzzing sound.
In flight, a housefly can turn off one of its wings, which helps it sharply change its flight path, perform complex maneuvers, and take off from a standstill without a preliminary run-up.
Belly
The abdomen of a housefly has the shape of an elongated cylinder.
Segmental, represented by ten interconnected segment particles.
Fly body
Inside the abdominal cavity there are organs of the reproductive, respiratory, digestive and other vital systems.
The surface of the abdomen is covered with a chitinous layer with good elasticity. If necessary - after eating and during the period of bearing offspring - the cover can expand.
Internal structure
The internal structure of the fly is represented by the digestive system, reproductive system and other organs important for the life of the insect.
Digestive system
The abdominal cavity of the insect contains the main part of the organs responsible for and ensuring the absorption of food.
This:
- goiter;
- intestines;
- Malpighian vessels;
- excretory tubules.
The housefly does not have a digestive system in its direct sense. Food is digested before it enters the insect’s gastrointestinal tract, i.e. food enters the cavity of the goiter in a form completely ready for absorption. Before the fly begins to absorb food, it treats it with a special secretion, which ensures its digestion.
Sexual and reproductive system
The abdominal cavity also contains the internal genital organs. In males these are testes, in females these are eggs, accessory glands and ducts.
The external genitalia of housefly subspecies have their own characteristic features.
Males are distinguished by the special structure of their grips, with the help of which they hold the female during the mating process.
Fly egg laying
The number of eggs in a housefly clutch varies and can reach 70 – 150 pieces. The number depends on the subspecies of the insect.
Other insect body systems
The brain consists of numerous nerve nodes that are located in different parts of the insect’s body. The complex brain system inherent in humans is absent in insects.
The main task of the brain is to help coordinate movements. Another organ is responsible for reflexes - the reflex arc.
The brain is tiny in size but made up of several hundred thousand neurons. This helps the insect perform incredibly complex maneuvers during flight.
The circulatory system is represented by the following organs:
- aorta;
- pterygoid muscle;
- dorsal vessel;
- heart.
The heart has a simple structure. The organ does not perform functions familiar to humans.
The circulatory system is filled with blood - a completely colorless or slightly yellowish liquid.
Diagram of the circulatory system of a fly
The main function of this biological fluid is to transport the nutrients necessary for the insect. It does not take part in the transfer of oxygen and does not contain red blood cells.
The respiratory system is represented by a large number of tracheas, which are located throughout the body. The flow of oxygen into the respiratory canals is ensured by the opening of the spiracles.
The trachea, in turn, are highly branched, representing a rather complex capillary system. Thanks to this, oxygen is supplied directly to vital organs.
In total, the insect has 10 pairs of spiracles: two are on the surface of the chest, the remaining eight pairs are on the lower surface of the abdomen.
Conclusion
The housefly, despite its outward primitiveness, is a flying two-winged insect with a rather complex internal and external structure.
Evolution [edit]
Like most external features of arthropods, the mouthparts of six-legged algae are highly developed. Insect mouthparts exhibit many different functional mechanisms across the wide variety of species considered insects. Of course, significant homology is retained when matching structures are formed from matching primordia and have the same evolutionary origin. On the other hand, even structures that are physically nearly identical and also have nearly identical functions may not be homologous; their similar functions and appearance may be the product of convergent evolution.
Piercing and sucking insects[edit]
A number of orders of insects (or, more precisely, their families) have mouthparts that pierce food to enable the internal fluid to be sucked. Some are herbivores, such as aphids and leafhoppers, while others are carnivorous, such as killer insects and mosquitoes (females only).
Proboscis [edit]
A distinctive feature of the order Hemiptera is the presence of an oral apparatus, the jaws and upper jaws are transformed into a proboscis, enclosed in a modified lip shell, which is capable of piercing tissues and sucking out liquids. For example, true beetles such as scale insects feed on plant fluids. Predatory insects such as assassin beetles have similar mouthparts, but are used to pierce the cuticle of captured prey.
Stiletto [edit]
Mosquito bites human finger
Female mosquitoes have all elongated mouthparts. The labrum covers the rest of the mouth like a vagina. The upper lip forms the main feeding tube through which blood is absorbed. There are paired jaws and maxillae, which together form a stylet used to pierce the animal's skin. During piercing, the lip remains outside the skin of the food product, bending away from the stylet. Saliva containing anticoagulants is injected into the food and blood is sucked out through different tubes.
Pumping insects[edit]
Australian thistle with its proboscis extended while feeding
This section considers only those insects that feed by sucking liquids, usually without first piercing the food, without wiping or licking. Common examples are adult moths and butterflies. As is common with insects, there are variations: some butterfly species, such as Serrodes
and
Achaea
, puncture fruit to such an extent that they are considered serious pests of orchards. [8] Some butterflies do not feed after emerging from the pupa and have greatly reduced, vestigial mouthparts or no mouthparts at all. All but a few adult Lepidoptera lack jaws (a superfamily known as mandibulate butterflies). have fully developed mandibles in adults), but also have remaining mouthparts in the form of an elongated sucking tube, the proboscis.
The proboscis of a butterfly, showing the structure of its two galleries
Proboscis [edit]
The proboscis, as seen in adult Lepidoptera, is one of the defining characteristics of the morphology of the order; it is a long tube formed by paired galeae of the maxilla. Unlike the sucking organs of other orders of insects, the proboscis of Lepidoptera can be rolled up so completely that it can fit under the head when not in use. However, during feeding it spreads, reaching the nectar of flowers or other liquids. In some specialized pollinators, the proboscis can be several times the length of the butterfly's body.
