1 FORM, STRUCTURE AND BIOLOGICAL CHARACTERISTICS OF COFFEE
1. Morphology and structure of Ca cuong
fix it
Ca cuong has a small shape like a cockroach. But in maturity it can be long 7 – 8cm. Its body has a flat leaf shape; clearly distinguish the first, back and stomach. It has 2 wings and 3 feet. If you look closely you will see it there 2 breathing holes at the end of the abdomen and 1 the stoma of the aromatic gland is located on the abdomen, between the base of the forelegs. Its chest part has 3 burning and belly have 7 burning. The three vertebrae are covered with a hard plate called the chest plate. Its mouth structure is stinging. It has front and rear wings. The front wing has two distinct parts: the base is thick and hard, the tops are thin. (So, they also call them half outfit).
Ca cuong is yellow brown to black brown. The color of the wings is darker than the belly. On the feet there are gold cavities, dark brown alternating.
Each of its legs are composed of joints connected to each other. The first feet are always facing the front. It has sharp claws, looks like a pair of swords of the heroes. These legs are used to grip and capture prey. The legs at the back also have claws but are flat, long to accommodate swimming. All three legs were growing from the chest, corresponds to three burns: before, middle and back.
The whole Ca cuong body is surrounded by 1 thick cuticun crust. Therefore, to grow up, Ca cuong must molt.
Ca cuong mature
The belly of a mature ca cuong
The structure of Ca cuong is similar to that of other insects. It includes the digestive system, excrete, cyclic, Respiratory, nerve, Endocrine, genitals and senses. Especially, it has an aromatic gland on its body. The aromatic gland opens with a stoma located in the middle of the chest, the right edge of the first foot.
Like other insects, Their hatched eggs do not become adults immediately, but undergo a lot of metamorphosis before becoming adults.. For example: Bee, butterfly, fly,… When the eggs hatch, a worm is formed. Those worms undergo a lot of metamorphosis before gradually forming bees, butterfly, fly,… It is called a complete metamorphosis (Ie shape at an early stage with a completely different end stage).
Ca cuong larvae
But in Ca cuong, the metamorphosis is not complete. New Ca cuong bodies hatch from eggs (called larvae) Through periods of metamorphosis, they all have shapes similar to those of an adult. It has 5 metamorphosis stage. Every stage, it molts to grow up. And then 5 when molting, it becomes an adult Ca cuong.
2. Classification and geographical distribution of Ca cuong
a) Classification location
In Vietnam, Ca cuong is also known as cinnamon, zinc coffee. From year 1775, after collecting specimens in India, Two scientists, Lapetetier and Serville, have identified the scientific name for Ca cuong. How about in Vietnam, right from the year 1928, Engineer Nguyen Cong Tieu has recorded Ca cuong is an edible insect.
The current, Ca cuong species of Vietnam is classified as Ca cuong, they swim feet, Set of Half-wing Insects and Class Insects.
It is calculated that, now in the world, Ca cuong has come 24 species. Ca cuong species of Vietnam (whose scientific name is Lethocerus indicus) is the largest size Ca cuong species (as described above, its body can be extended 7 – 8cm. But also documents that, It can also be up to 11cm long!).
b) Geographical distribution in Vietnam
Ca cuong is found in almost all provinces, throughout the three central regions, male, North of our country. It is present in the plain, Midlands and Mountains. We often see Ca cuong in the swamps, lake, to the, wet rice fields and water bodies with aquatic plants growing.
Due to the exhausting exploitation and the pollution problem of the pesticides is too great, the Ca cuong population is getting less and less.. Even, in many places, there is no longer any Ca cuong figure. So, Ca cuong has been recorded in the Red Book of Vietnam (2007).
c) Distributed in the world
It is found that Ca cuong is found in many countries in South and Southeast Asia such as India, XriLanca, South China, Myanmar, Laos, Thailand, Cambodia and Indonesia. It is identified as endemic to Southeast Asia. However, The current general situation is that too much pesticide is used in the field, so the number of Ca cuong in different places is minimized.. In many countries there are programs to restore the Ca cuong herd.
d) Habitat
Ca cuong prefers to live best in calm or slow flowing freshwater pools where aquatic plants are abundant.. That is also the place where the animals used to feed Ca cuong. So, This is the most attractive environment for Ca cuong to live. We can order the water pools that Ca cuong likes best from high to low includes: paddy fields, to the, lake, The lagoon has many growing aquatic plants and large lakes. Sometimes, We also meet Ca cuong on land, but very rare. Ca cuong was not found in salt water bodies. It does not survive in salt water or brackish water conditions. So, In coastal areas, we rarely see Ca cuong.
In Vietnam today, in intensive rice growing areas, We rarely meet Ca cuong. Our relatives used too much pesticide and used it continuously, so Ca cuong was almost completely eliminated. So, in remote areas, In the wild without any cultivators, we can see Ca cuong. It can be considered as an indicator animal to evaluate the level of pesticide contamination for us.
3. Biological and ecological characteristics of Ca cuong
a) Embryo and metamorphosis
Ca cuong lays eggs. Eggs are attached in nests around aquatic plants, piles sticking out of the water. Each nest has dozens of eggs, even hundreds of eggs. Immediately after giving birth, the egg already has an embryo development process inside. Depending on the environment, the eggs can hatch later 5 – 10 day. In the process, the embryo forms and develops into a larva. When the eggs hatch, the larvae will be born. The larvae will experience 5 stage (which people call age: age larvae 1, year old 2, year old 3, year old 4, year old 5). Want to pass an age, it has to molt. After each molting, the larvae will get bigger. At the age of 1, Their size is wide × length 0,4 × 0,9cm. But come of age 5, it was 2,1 × 5cm. Now, its shape resembles an adult.
Time to develop from eggs, through the larvae stages up to adulthood completely dependent on the environment, especially the food source. If conditions are favorable, that process is shortened.
We know that, around Ca cuong body (from larval stage to adulthood) is a thick and hard cuticun crust (The main ingredient is chitin). Like many other insects, want to grow up, it must remove its old "armor" and replace it with a new "armor", Wider. That process is called molting. Scientists call it a metamorphosis. But in Ca cuong, as noted above, is an incomplete metamorphosis. The larvae are similar to the adults.
Larvae stages, from age 1 age 5 all live underwater. It functions like other aquatic animals. It can't fly because it has only wing buds. The wing buds will develop gradually. It is not until the last stage of molting to become an adult that the wings are fully developed. At that time, it has two wings and a cuong to fly. Their bodies are now larger in size, average reached: Length is 5cm and wide is 2.1cm. As stated above, Depending on the food conditions, its growth rate differs. Many authors believe that, Ca cuong can be long 7 – 8cm. Someone also said that, it can be up to 11cm long!
The lifespan of Ca cuong is approx 1 year. No author has determined that Ca cuong can live longer. It died of old age, or be hunted by an enemy, or encounter harmful agents (as plant protection drugs).
b) Ca cuong's food
Ca cuong is classified as an aggressive prey-catching insect. It is considered a carnivore. That is not correct. It does not eat but sucks. The structure of its mouth is stinging.
When catching prey, Ca cuong mobilizes all three feet. The hind legs help Ca cuong swim quickly to the prey to catch. The forelegs will grab and hold on to the prey. When you have prey, it stabbed directly with a pointed nozzle. Its salivary glands contain enzymes that will break the prey body into fluids. Then the ca cuong will suck all the fluids into its body. That is a full meal.
Ca cuong's food is very rich. Usually it looks for young fish, the tadpoles of frogs, clones. There is also a case, it catches frogs, adult clones. Besides, molluscs such as clams, Snails also attack. It is also found that there are cases, it even clings to small vertebrates like snakes, water bird to suck blood. Even terrestrial species, If there are favorable conditions, Ca cuong will rush in immediately. Rake, Grasshopper, crickets,… easily the delicious bait of Ca cuong.
However, Ca cuong only finds live individuals. It does not feed on dead prey or immobile prey. It watched carefully before attacking. It often swims lazily above the water or hides behind aquatic plants to hunt for prey. Its stalking posture is also different: it clings to aquatic plants, head down in the water, the tail with the tip of the snorkel stuck out above the water. In that position, Prey is difficult to spot the enemy. It looks mixed with body, leaves of aquatic plants. When detecting prey, Ca cuong hold the posture to observe. Only when the prey gets close does it come out to pounce. Her forelegs were tightly hooked up with a sharp hook and she immediately injected the anesthetic with her syringe. Later, it pumps enzymes into its prey. Everything happened very quickly. The prey is still clutched to death. Enzymes dissolve the organic matter in the prey body into solution. Ca cuong will absorb the fluid instead of biting, Tear prey like other carnivores.
In the larval stages, Ca cuong also catches prey like an adult, but the ferocity is less.
In the water bodies, If the density of Ca cuong is thick and the food source is limited, we can observe the phenomenon of Ca cuong eating each other.. This is also seen in many other species such as baba, a frog, eel,…
c) An enemy of Ca cuong
Lives in water bodies, Ca cuong is also always threatened by other larger predators such as fish, a frog, clones, reptiles and birds, interesting. Mutual annihilation is the law of nature.
However, The biggest risk to Ca cuong is people. Human life is enhanced the more the demand for trench coat, the larger the taste. Ca cuong is often cleaned to serve restaurants. The higher the price, the more it gets caught. In many places, almost no longer the figure of Ca cuong.
Other way, Our agricultural area is in turmoil. Many rice growing areas have now been leveled to build factories. Almost all of the fallow wetlands has been utilized for production. Therefore, the living environment of Ca cuong is also narrowed down.
But the biggest risk for Ca cuong species is that our people use too much pesticide. Ca cuong is very sensitive to pesticides. When it comes to pesticides, it dies! Yet now, pesticide use has exceeded thresholds and is at alarming levels. People are also poisoned by a pesticide called Ca cuong! Maybe, this is the numerical cause 1 leading to the state of all ca cuong in the field.
So, Raising Ca cuong in artificial conditions is a great opportunity to gradually revive our Ca cuong herd.
d) Reproduction of Ca cuong
Ca cuong is a single species, that means there are males, separate children. Their reproductive organs are similar in structure to other insects and the fertilization process is internal fertilization.
Their breeding season is in the summer, usually in months 6, 7, 8 and 9 (calendar). They are usually concentrated in well-lit areas. In contryside, the lampposts near the fields are usually where Ca cuong reaches the most crowded. They tumbled to show off and lure the couple. Later, they lead to each other to neighboring waters to mate.
It is very difficult to distinguish a male from a female. Usually the male is smaller than the female. If we look closely we see, under the chest of the male, right back there 2 A small tube is called a ca cuong. It is composed of a large blister and a small blister. The large puffiness is located on the abdomen and is ivory-white in color. It is a water balloon. When it pressed its stomach, water gushed out. Smaller puffiness on the chest side is ivory green. It is puffiness that contains Ca cuong oil. This bladder develops in males; in children, if, is very small.
Male Ca cuong often uses its feet to kick hard into the water to make a sound, both create a flow to signal and appeal to children. It also secretes aromatic substances to provoke a sexual partner. It is a typical pheromone of Ca cuong. The female easily recognizes the "call of love" and leans over to the male.
Now, The male slowly swims out, hovering around the ca cuong female. It must test whether the children like it or not. If there is no movement, considered children "falling in love". Now, The male ca cuong will crawl closer and climb onto the female's back. It uses all three of its legs to hold the female and submerge it in the water. It presses its genital appendages, located on the sixth abdomen, into the female genitals, also on the sixth abdomen.. Fertilization will take place. However, Males don't just mate 1 times. It was found to mate repeatedly with females. Everything happened in the water.
Finished, The male leads the female to crawl over the tree overhang that it has previously selected and marked. Females saliva and lay eggs on it. It attaches eggs in patches to the tree trunk, looks like the egg patches of a golden snail. However, Pink yellow snail's egg, Eggs of ca cuong are ivory white. This whole mating and egg laying process takes hours.
After laying all the eggs, Ca cuong is considered to have completed the task, it jumped into the water and disappeared. The rest is done by the male. Males will often use their wings to fan the eggs and come up, Come down to get water to wet the eggs. When there is movement, It also put the body of the bag on the nest to protect it, The front forks are often extended to intimidate enemies.
Male eggplant holding an egg
Each nest of eggs is about 2 – 3cm. They connect the eggs in a vertical line, regular. Each row has up to 10 – 12 egg. The rows are crammed together into an array, cling firmly to the stake or the stem of the aquatic plant, away from the water 10 – 20cm.
Egg custard
Depending on the conditions, the eggs can hatch later 5 – 10 day. It has two different heads. The small end of the egg faces inward and adheres firmly to the substrate. The large end of the egg is facing outward. It's the lid of the egg. When blooming, The larvae will come out through that cover to leave the shell and fall into the water. Larvae immediately begin independent life. Chief 5 larval stage, It all lives in the water. Depending on the environment and food sources, it grows quickly or slowly.
It also depends on the environment and food source that the process from eggs, going through the larval stages to become an adult takes 60 – 70 day.
e) The behavior of Ca cuong and the role of aromatic glands
Just like animals in nature, Ca cuong must also have active behaviors to adapt to the living environment.
The behavior of ca cuong is very typical, it can represent insects. Habits can be acquired by instinct or learned in the course of life. To be able to perform the calculation, Ca cuong also have enough organs to conduct communication between them with the environment and with other animals. Their organs of communication, like those of insects, include sight, hearing, touch and the specific chemicals they secrete. Taste communication is very common in insects. These species-specific odorants are called pheromones. In Ca cuong, Its pheromone is an essential oil with a distinctive aroma. Asians love that smell. They often mix it with dipping sauce or fish sauce to create an attractive taste. It is said, in the larval stage, Ca cuong doesn't have that gland yet. Time to grow up, Both males and females are present, but in males it is much larger. The aromatic gland helps the animal to mark it to distinguish the individual territory of each individual. Other way, The aromatic gland also signals and calls for "sex partners" when the breeding season comes. It is also to mark the location that it has chosen for the cows to lay eggs on,…
Along with the secretion of aromatic glands, Male Ca cuong has many other behaviors such as: kick the water to call the children; Replace the children to care for and protect the eggs; know to fan and fill the egg with water so it won't spoil; know how to embrace the whole egg nest to avoid the destruction of the enemy. While patiently looking after the eggs of the female first, it continues to mate with many other females.
In children, there is a habit of "jealousy". After being mated by a male, it climbs up to find the nest of eggs first and breaks it with its feet. Even, it uses its trunk to suck up all the nutrients in the eggs that the previous female has laid. Later, kick all those eggshells into the water.
The behavior of the male is also strange: just resolutely protect the female's eggs first, flirting and mating with the following females. It is often tricked by the female to leave the nest. At that time, The new female rushes in and quickly destroys the female's eggs first. Sometimes, If it can't break it, it will lay eggs in the female's nest first. So, there are nests of eggs that hatch in batches due to eggs laid by many females at different times.
A "bad" habit of ca cuong (which many other animals also have) is when there is no food, it can eat even a small eggplant. This we must be very careful when organizing raising them.
Ca cuong has good camouflage ability. Its color is easily mixed in the leaves, bunches of aquatic plants. Sometimes it touches our eyes without us noticing. Its stalking behavior is very effective. It usually remains motionless when it detects termites. It only pounces when its prey is close. Therefore, Its catch is very effective.
When the male meets the female during the breeding season, it's also very cautious. It has to hover and watch closely to keep an eye on the children. When it's "sure to eat", it will start. It has the habit of "worrying away". It has to find a favorable place for the female to lay eggs before thinking about mating. Even when he went to the bright area near the base of the lamp post to find his children, he knew that there were favorable water bodies around to lure the children there.. Everything looks like it's been calculated, but in reality it's just instinct. The delicate mating process is also instinctive!.
The behavior of Ca cuong has helped it adapt to the environment and preserve the species. We should respect these behaviors when doing the multiplication of Ca cuong.
g) The value of Ca cuong
Food value:
Ca cuong is considered to be an animal that has been used as food for humans since ancient times. Both the Ca cuong meat and eggs are processed as food. Many old people have confided to us about the time when they were herding buffalo in the fields - the children at that time used to go out looking for eggs and bake together.. The old men said: “There are no foods that smell good, fleshy and creamy like egg ca cuong! In life, Each person must at least eat egg cuong 1 times!”.
But the most precious thing about ca cuong is its aroma gland. It's a typical spice. In the Red Book of Vietnam it is said that, from the Trieu Da period (III - II centuries BC, i.e. more than a while ago 2000 year) Our people have considered Ca Cuong as a "mountain moat"., seafood". It is often chosen to send tribute to China under the name "Cinnamon Ginseng".. Currently, in Vietnam and Southeast Asian countries, Ca cuong is still considered a high-class and very popular food.. When eating rolls, bun thang, no, cha,… but adding a drop of Ca cuong essential oil to the bowl of dipping sauce will bring into full play the value of these cuisines. Prices can sometimes go up 50.000 VND/1 drop! So, Many chemical laboratories have found ways to synthesize Ca cuong essential oil. But, How fragrant are those synthetic compounds?, as delicious as ca cuong in nature. Therefore, Raising natural ca cuong is the right direction.
Medicinal value:
Right from the year 1952, Two scientists Adolf Butenandt and Nguyen Dang Tam have researched the chemical properties of Ca cuong essential oil.. They said: Ca cuong essential oil dissolves in fat; boiling point at 168OC – 170OC; Its index of refraction is n.(25/D).1,4160; it is not denatured by distillation; Infrared spectrum shown at 5.80m; has a specific range of carbonic acid esters and has identified the aromatics of Ca cuong essential oil as a hexanol acetate with the formula C.6H11OCOCH3.
Uses of essential oils:
Long time ago, We only use the essential oil of Ca cuong to serve meals, but few people pay attention to its uses. Other way, Because when we use it, we only use it in a very small dose, so no one notices its harmful effects when used a lot.
Scientists tell us: When using ca cuong essential oil in small amounts (as we still use) It has a stimulant effect on the nervous system and stimulates the sexual organs. So, Ancient Chinese kings loved and encouraged our kings to pay tribute.
However, Scientists also warn, If you use Ca cuong essential oil in high doses, it is also very easy to cause poisoning. So, no matter how much you like it, But when we put Ca cuong essential oil in the bowl of dipping sauce, we should only use a small amount 1 drops/bowl only.
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