Why do pitcher plants eat insects? What is the reason
The pitcher plant is the collective name for all species in the genus Nepenthes, belonging to tropical carnivorous plants, with its place of origin mainly in the tropical regions of the Old World. The structure of its leaves is complex, divided into petiole, leaf blade and tendril. The inner surface of the lid of the pitcher-shaped body can secrete a fragrance to lure insects. The tail end of the tendril expands and curls back to form a pitcher shape that can capture insects. Now let us take a look together at why pitcher plants eat insects!
Why do pitcher plants eat insects?
Most pitcher plants live in environments with relatively high humidity and temperature and with bright diffused light, generally at the edges of forests or shrublands or in open areas. A few species, such as Nepenthes ampullaria, prefer to grow in dense, dark forests, while most species have adapted to growing among grass populations similar to grassland species. The reason they eat insects is that pitcher plants originally lived in places with extremely harsh environments and could only rely on preying on insects to sustain life, and this behavior gradually evolved into their habit.
How do pitcher plants capture insects?
The insect-catching pitcher of the pitcher plant has a rather special structure. The inner wall of the pitcher has a lot of wax and is very smooth. On the inner wall there are about 1,000,000 digestive glands, which can secrete a large amount of colorless, transparent, slightly fragrant acidic digestive fluid after the pitcher plant catches an insect. This digestive fluid contains amines and coniine that can paralyze and poison insects. At the same time, on the inner side and edge of the lid of the insect-catching pitcher there are many nectar glands, which can secrete fragrant and sweet nectar to lure insects. When the insect-catching pitcher opens this honey-pot lid, it attracts many greedy small insects. Once a small insect falls into the insect-catching pitcher, the lid will immediately close automatically, and the insect quickly becomes poisoned and dies. Before long, all the limbs are digested and absorbed as nutrients for the pitcher plant.
What growing conditions do pitcher plants have?
1. Light: Light is one of the most important factors in growing huge and brightly colored insect-catching pitchers. Providing sufficient air humidity, medium soil moisture and ample light can make the leaves take on a red like red wine. The plant can be acclimated to accept some direct sunlight, preferably morning sunlight. On the contrary, full sun will make the plant's color become dull and hinder the plant's growth.
2. Water: Unlike other carnivorous plants that only need to keep the soil moist during the growing season, when growing pitcher plants the soil must be kept moist at all times, and the growing medium should preferably be loose and not squeeze out water. Therefore, watering is more suitable for pitcher plants. However, the water immersion method can still be used to supply water, but the air permeability of the cultivation medium needs to be improved and the proportion of large-particle cultivation medium increased, so as to avoid the cultivation medium becoming too wet.
3. Humidity: The level of air humidity is the key to whether pitcher plants can normally produce pitchers. Under natural conditions, pitcher plants usually grow in relatively humid areas, with humidity of at least 60%. Therefore, in cultivation, many people always encounter the problem that pitcher plants cannot grow new pitchers; the pitchers often wither as if scorched before they have even grown large. The main reason pitcher plants do not grow pitchers is that the environment is too dry.
4. Temperature: Pitcher plants are widely distributed in altitude, from flat ground to high mountains above 3,000 m above sea level. In horticulture, they are divided into two major categories, highland species and lowland species, according to their distribution by altitude. Pitcher plants growing in high mountains above 1,200 m above sea level are highland species, with cultivation temperatures of 21°C during the day and 10°C at night. Pitcher plants growing on flat ground or in areas below 1,200 m above sea level are lowland species, with cultivation temperatures of 29°C during the day and 21°C at night.
5. Nutrition: The pitcher plant is a carnivorous plant and already has the ability to obtain nutrients by catching insects or small animals. These carnivorous plants are all very efficient insect catchers. Growing pitcher plants does not require specially feeding them insects. Pitcher plants grown outdoors can usually catch insects on their own. As for whether regularly providing them with some insects will make them healthier, make their insect-catching pitchers larger, or make them more cold-resistant, there is not yet sufficient evidence to prove it.