Coleoptera ( pronounced yuánjīng ) is the common name for the Beetle of the Coleoptera family Meloidae , called " blister beetles " in English , meaning " blister beetles " in Chinese . Why are they called "blister beetles"? Because when attacked, coriander often secretes a yellow liquid from its foot and leg joints, which contains a chemical called cantharidin, which can irritate and make people's skin red, even form blisters, and have an unpleasant odor. Not all species of coriander cause blisters, but caution should be exercised when coming into contact with beetles of the coriander family.
Adult coriander can feed on a variety of crops and may even cause harm to livestock. However, coriander larvae can prey on eggs or larvae of some other pests, such as locusts. Therefore, coriander is both beneficial and harmful to humans.
First, the morphological characteristics of coriander
On the outside, coriander resembles many other beetles, such as soldier beetles and darkling beetles. However, coriander also has some unique morphological features that can help people identify them. Their elytra are soft and not stiff, as if covered with fluff. The forewings wrap around the sides of the beetle's abdomen. The forebrea of coriander is usually cylindrical or spherical, narrower than the base of the head and elytra.
Most adult corianders are medium in size, with the smallest species only a few millimeters long, while the largest can reach up to 7 cm long. Their bodies are usually elongated, with filamentous or rosary antennae, but also in other shapes. Many species of cilantro are dark and monotonous, but there are also some species that are bright and vivid. Coriander can be collected on the flowers or leaves of some plants.
Second, the taxonomic status of coriander
Animalia
【Gate】Arthropoda
【Yamen】Mandibulata
Insecta
[Subclass] Pterygota
【Order】Coleoptera (Coleoptera)
【Suborder】Polyphaga
【General Section】Tenebrionoidea
【Family】Coriander (Meloidae)
Third, the feeding habits of coriander
Adult coriander are plant-feeding, feeding on plants, especially those of the legume, asteraceae and nightshade. Although coriander is rarely considered a major crop pest, they do sometimes form large feeding populations in farmland, causing some losses to agricultural production. Many coriander feed on the flowers of the host plant, while some species feed on the leaves of the plant.
Coriander larvae have an unusual feeding habit. Some species of coriander larvae specialize in preying on locust eggs and play an important role in controlling the growth of locust populations, so they are considered beneficial insects. Some species of coriander larvae can prey on insect larvae. There are also some coriander larvae that feed on the bee larvae that nest on the ground, and in these species of coriander, the first-instar larvae may adhere to the adult bees, fly back to the hive, and then settle in the hive to feed exclusively on the offspring of the bees.
Fourth, the life cycle of coriander
Coriander, like other beetles in Coleoptera, is a completely metamorphosed insect. But somewhat different from the general fully metamorphosed insect, the first-instar larvae of coriander have fast-moving feet and well-developed antennae, and are very active, and the larvae of this age are called triungulins. Because these early larvae are intended to be parasitic, they move around to find their parasitic masters. Once they find a suitable host (e.g. in a hive), they settle down to feed, and the larvae are usually less active at all stages, and the feet gradually become smaller or even disappear. During the growth and development of coriander larvae, the morphology of the early and late stages is very different, and it seems to have an additional insect state, which we call hypermetamorphosis.
The last larvae of coriander are inedible and called pseudopupa, which also overwinters with pseudopupa. Depending on the species and environmental conditions, the life cycle of cilantro can vary from up to three years. However, most species complete a full life cycle within a year.
5. Coriander behavior and defense
Coriander's body is soft and seems vulnerable to predators, but they are not defenseless. Their bodies produce a corrosive chemical called cantharidin, which, when threatened, leaching from the joints of the foot as a chemical weapon against predators, a defense strategy called "reflex bleeding." Species with a high content of cantharidin, if it sticks to the skin of a person during treatment, can cause blisters on the skin. Cantharidin is also an effective repellent for ants and other carnivores, but if it is ingested by humans or animals, it can produce a serious toxic reaction. Horses are particularly sensitive to cantharidin poisoning, and cantharidin poisoning occurs if their hay feed is contaminated with cilantro secretions.
Sixth, the distribution of coriander
Coriander is widely distributed throughout the world, especially in arid or semi-arid regions, and its species diversity is the highest. Globally, nearly 4,000 species of cilantro have been discovered and described. Among them, there are 130 species in China and more than 400 in the United States and Canada.