In addition to repellents and insecticides, mosquito control mainly comes down to preventative methods using natural remedies to control the spread of these insects. Numerous methods rely on the use of animals that are natural predators of mosquitoes. As you know, the ecosystem is absolutely balanced, and if mosquitoes feed on our blood, it means that other animals feed on these insects. But who eats mosquito larvae and the mosquitoes themselves? Today we will try to answer this question.
Larval stage
The most famous animal that eats mosquitoes is definitely bats.
However, there are many other predators in nature that few people know about. These include, but are not limited to, other insects, amphibians and even fish.
First of all, we should not think of mosquitoes only in their adult form (flying insects). The fight against this “bloodsucker” is carried out even when the insect is in the larval stage of development.
Pupae
Mosquito pupae are comma-shaped. They are agile and can quickly dive from the surface of the water in case of danger, and if left undisturbed, they will soon surface again. The head and thorax merge into a cephalothorax, with the abdomen curving underneath. The pupae do not feed. The respiratory openings of the pupa are not located on the abdomen, as in larvae and adults, but on the upper side of the chest, which the insect holds near the surface during breathing, and through which the mature adult emerges. On the empty pupa shell, the mosquito waits until its wings dry out (usually about an hour) before flying. Males often hatch earlier than females.
Insectivorous birds
Birds eat insects. This is no longer a secret. The main birds that massively destroy mosquitoes are swallows. However, the problem is that mosquitoes are only part of the swallow's diet. These birds do not focus their attention on mosquitoes, simply eating all the insects in a row.
An interesting fact is worth noting. It lies in the fact that in our country mosquitoes over the past 50 years have become much larger than before, while the birds of prey that exterminate them have become considerably smaller.
Lifespan
The average lifespan of a female C. p. pipiens f. molestus is highly temperature dependent. In laboratory conditions, on a carbohydrate diet at 25°C, females live on average 43 days, at +20°C - 57 days, and at +10...+15°C - 114-119 days; In the absence of food, life expectancy is greatly reduced. The lifespan of males in all cases is much shorter, so at +25°C it is only 19 days. The lifespan of Aedes mosquitoes that diapause during the egg stage is shorter: they are born in the spring, reproduce, and die by the fall. Males usually live for about 5-7 days.
Reptiles and amphibians
Some reptiles include mosquitoes on their menu. For example, the gecko eats mosquitoes from morning to night. The lizard includes them in its diet, like other small insects, and together with some amphibians (for example, newts) they normalize mosquito populations in their natural habitat.
Frogs and tadpoles also fight mosquitoes. The former only occasionally feed on adults, while the latter eat the larvae themselves. But even if they do not eat the larvae, they consume the same aquatic nutrients as the larvae, thereby creating competition for them in terms of development.
Male nutrition
Males do not have piercing teeth to pierce the skin, so they do not even physically have the opportunity to feed on the blood of animals and humans. The mosquito's diet is based on plant sugar, pollen, flower nectar and honeydew. Blood is exclusively the diet of females, which helps them actively reproduce.
Most often, males choose plant nectar, which is located in the sepals of the flower. Scientists define this method as parasitic feeding, since in the process of eating plants they can harm them. In this case, the diet does not change even after the individuals mate.
Males feed on plant nectar
The male mosquito does not drink blood
If an individual receives additional protein from the blood, this can significantly extend the life of the mosquito. However, only the female has such an instinct, which over such a long life cycle can mate several times and lay eggs, thereby increasing the number of offspring. The male has a more primitive metabolism, so he simply will not be able to process the protein entering the body, and the trunk will not be able to pierce the skin.
The male has a more primitive metabolism, and the trunk will not be able to pierce the skin
Due to this mechanism, a natural balance is maintained between individuals, and the expenditure of resources is distributed for the reproduction of offspring. At the same time, eating plant foods still contributes to a longer life of the insect compared to other species.
Gambusia
Gambusia is a small fish that loves to kill mosquito larvae.
In common parlance, this type of fish is also known as “mosquito-eating fish.”
Gambusia Affinis is a small (up to 5 cm), silvery fish. Gambusia eats mosquitoes (at the larval stage) with such an appetite as if it were living its last day. She herself is a native of America. But in history there is the fact that Gambusia saved Italy from the invasion of malaria mosquitoes. In the 1920s, many specimens of this fish were transported to Italy, and thus managed to overcome the malaria epidemic.
Description
The body of mosquitoes is thin, elongated; legs are long, thin; The abdomen is elongated, lean, consisting of 10 segments. The thorax is wider than the abdomen, specialized for movement, three pairs of legs and a pair of wings are attached to it. The paws end in a pair of claws. The wings are small, narrow, transparent, covered with scales. The eyes are complex, clearly separated from each other. The antennae are long and consist of 15 segments. The mouthparts are piercing-sucking type. In females the proboscis is long and consists of piercing bristles, in males it is without them. The oral apparatus is hidden in the tube-shaped lower lip. Inside it are several saw-like jaws. With its jaws, the mosquito cuts a hole in the skin, plunges the proboscis deeper to the level of the blood capillaries, and through the same oral appendages, as if through a tube, it sucks blood.
Tench
One of the largest eaters of mosquito larvae is tench. For this reason, this fish is widely used for biological mosquito control.
Tench is a fish of the Cyprinidae family, about 35 cm long, which can weigh up to 5 kg. It lives in freshwater basins and is widespread in Europe and Western Asia. As a habitat, it prefers muddy bottoms and stagnant waters rich in aquatic plants, on which it lays its eggs, between May and June.
The adult fish eats up to 1,500 mosquito larvae every day, becoming one of the most used natural predators in the fight against this pest.
Mosquito breeding process
These are bisexual creatures, so a male and a female participate in the reproduction of mosquitoes. Future offspring go through 4 stages of development, which are typical for insects with complete transformation:
- egg;
- larva;
- chrysalis;
- imago (sexually mature individual).
Moreover, insects are “land” creatures only in the very last stage of mosquito development: all the rest live in bodies of water or in the immediate vicinity of them. After all, they need water to develop.
Reproductive system of mosquitoes
Representatives of the family have internal fertilization: after mating, the male’s seed enters the female’s reproductive tract, after which the formation of eggs begins. The reproductive organs of mosquitoes are located inside their abdomen: ovaries in females and testes in males. The microscopic external genitalia of the male have a very complex structure, the features of which are key to distinguishing species that are externally similar to each other. Females have a small ovipositor in the form of a short tube: eggs are born through it.
"Marriage Games"
The type of mosquito mating is called “eurygamy” in biological terms. Its peculiarity is the formation of a swarm - a dense cloud of male insects staying close to each other. Surely everyone has seen such flocks on summer evenings.
Female mosquitoes attract the attention of the opposite sex with a thin buzzing sound similar to a squeak. This sound is created by the movement of the wings. Its frequency depends on the age of the individual, and males, with the help of their sensitive antennae, detect the slightest differences in sound, giving preference to more mature “girlfriends”.
When approaching a cloud of males, the female flies into it and finds herself fertilized by the one who managed to do it first. To complete the job, males have special appendages next to their genitals, with the help of which he holds the female in flight together.
It is noteworthy that mosquito populations living in cities are characterized by stenogamy - reproduction without swarming, the implementation of which is difficult due to the lack of large and free space.
After a short mating, the male flies away from the female and returns to the others. The female goes in search of blood necessary for the continuation of offspring.
Reproductive activity directly depends on the degree of saturation of the female with blood: with sufficient nutrition, she lays eggs every 2–3 days, after which she returns to the swarm of males
Eggs
Each time, females make large clutches containing 30–150 mosquito eggs. The malarial species are the most prolific, producing about 280 pieces. The exact number depends directly on the amount of blood drunk by the female, which explains the aggression of insects towards humans.
Usually the female lays eggs directly on the surface of the water. To do this, she chooses freshwater, calm and stagnant bodies of water with a minimum flow speed. Ponds and quiet backwaters of lakes overgrown with reeds are ideal. Less commonly, the mosquito lays eggs on well-moistened soil along the banks or near temporary reservoirs that dry up in the summer and refill in the spring after the snow melts. Sometimes the female chooses floating objects and plants (this is more typical for the genus of True mosquitoes, to which the famous squeaking mosquito is included).
Larva
Under favorable conditions, after just a few days, larvae enter the water from the lower end of the eggs. They look like small worms covered with hairs. The body color of a mosquito larva depends on the species. For example, in the squeak they are dirty gray, and in the jerk they are green or red. The latter are used in fishing and aquarium farming, where they are known as bloodworms.
The larva and the pupa that subsequently emerges from it necessarily need a sufficient amount of air. The larvae of some species live at the very bottom of reservoirs, buried in silt or mud, but must rise to the surface every 15 minutes to obtain oxygen. Others can swim for a long time, bending their whole body, on the very surface with the “tail of the body” upward, because this is where the worm’s respiratory organs are located - special tubes through which it breathes.
During its entire development, which lasts an average of 20 days, the larva undergoes 4 molts, after which it turns into a pupa. During them, she sheds her old exoskeleton, which allows her to increase in size each time. For example, immediately after emerging from the egg, the length of the larva does not exceed 1 mm, and after the last molt it can reach 1 cm. At the same time, the volume of the larva’s body increases even more: almost 500 times.
Doll
The mosquito pupa, the penultimate stage of insect development, has a more complex structure of internal organ systems. It also lives in water and periodically floats to the surface, preparing to transform into a flying individual. The waiting time takes approximately 5 days. Gradually it becomes darker in color.
The answer to the question whether a mosquito has a pupa is positive, since it is an insect with a full cycle of transformation.
The behavior and nutrition of the larva and the pupa are almost identical, but the latter has one interesting feature: thanks to its shape and well-developed tail, it can quickly move through the water column with spasmodic movements.
Imago
An adult is an adult insect that lives on land and participates in reproduction. Males live only 3 weeks, while females live 3 months, if the air temperature stays around 10–15 °C. Under unfavorable conditions, life expectancy is reduced.
Belukha
The beluga whale's body is covered with a thick layer of skin, the thickness of which reaches 15 centimeters. This thick skin protects beluga whales from injury when they swim among the sharp ice. And a layer of subcutaneous fat, the thickness of which is 10-12 centimeters, prevents them from getting too cold.
Seals and beluga whales do not freeze in the water due to their thick layer of fat.
Wintering for belugas is not easy; they constantly have to maintain ice holes so that they do not freeze, since these animals periodically need to rise and breathe fresh air. They break through the ice with their strong backs. But sometimes wintering ends tragically for them, when the polynyas are covered with too thick a layer of ice, and belugas are trapped in ice.
White or polar owl
These birds are distributed throughout the tundra. The color of polar owls is white, camouflage with a large number of black spots. Thanks to this color, snowy owls are well camouflaged in the snow.
In winter, polar owls fly to the forest-tundra and steppe zones. Also in winter they can fly into settlements. But some individuals remain in the nesting areas in winter, sticking to areas with a small amount of snow and ice.
polar fox
The polar fox is better known by another name - the arctic fox, which is famous for its snow-white fur coat. Arctic foxes are much smaller in size compared to their forest counterparts. The arctic fox's body length is 50-75 centimeters, and it has a gorgeous tail 25-30 centimeters long.
The arctic fox is a gorgeous decoration of the Arctic tundra.
There are white and blue arctic foxes, the latter have a darker coffee or gray body color with a bluish tint. Thanks to their beautiful fur, arctic foxes are valuable game animals. Blue foxes are the most prized.
Lemming
These are another small rodent, a family of hamsters that live in the cold tundra. They are not afraid of frosts due to their smooth fur and thick layer of fat. They remain active throughout the year and spend the winter in nests made in the snow. During the day, this small animal eats twice its own weight. They feed all day with short breaks, and also store food for the winter.
The little fat lemming is not afraid of severe frosts, because it is protected by the warm interstitial and subcutaneous fat.
check yourself
1) Show the tundra zone on the map.
The tundra zone is located along the entire coast of the Arctic Ocean, and is indicated in purple.
2) Give a brief description of the tundra zone according to the plan given on p. 71.
Brief description of the tundra zone for grade 4
- Zone name: Tundra
- Features of nature: Severe winters, two months of polar night, short summer, permafrost. Many species of birds, reindeer, arctic foxes, lemmings, and mosquitoes live here. Due to harsh winters, the vegetation in the tundra is stunted. Due to permafrost, the soil layer is very thin.
- Human use of the zone: Herds of reindeer graze in the tundra, oil and natural gas are extracted here.
- Environmental problems: soil disturbance, poaching, oil spills, impoverishment of reindeer pastures.
