Why does a flock of butterflies fly around a tree?

Butterflies fly around the iron tree because it is a pest called the cycad little gray butterfly.

The cycad small gray butterfly completes a generation of about 20 days in Beijing area, including 3 days for the egg stage, 5-7 days for the larval stage, 8 days for the pupal stage, and the adults after emergence lay eggs the next day. The insect occurs in Beijing from May to November, and the peak period of damage is from mid-June to mid-October. The adult will scatter the eggs on the curly new leaves of the iron tree, the larvae hatch into the curly new leaves and eat the mesophyll, with the growth of the insect age and leaves, often cluster in the bud scales at the top of the iron tree head or scatter on the more tender leaves to eat, when the young leaves are eaten only the petioles, sometimes the petioles are hollowed out, in the peak period of damage can appear in 3 days - 5 days young leaves wilted and dried up or the leaflets are all dried up and rolled, the leaves are incomplete after the leaves, and the top of the apex is rotten in case of rain, and the whole plant does not have new leaves all the year round. Loss of ornamental value.

The insect has overlapping generations and is relatively hidden before the infestation, and the larvae burrow into the buds to eat when they hatch, and when the new leaves are found to be damaged, they have caused losses. Although a single drug can kill a large number of larvae, because it cannot kill the adults and eggs, it will occur in large quantities after a week.

It is possible that a large number of pupae spend the winter in the cracks of the trees, and in the spring, when the climate warms and the temperature is suitable, it begins to feather, so that there are many butterflies on the trees.

The phenomenon of animal gatherings is not uncommon in real life, but it can be strange when a procession of colorful butterflies appears by the spring, thousands of them end to end. In the butterfly spring in Dali, Yunnan, there was such a beautiful and spectacular scene. At that time, not only were there thousands of butterflies flying over the spring, but even countless butterflies were staying on the branches of the trees, which were connected into a long chain and hung down by the spring like a colorful willow branch.

Many people saw it with their own eyes at the time, and they are still excited when they mention it. But in the midst of this excitement, there is also a faint sense of doubt and surprise.

The lifespan of butterflies varies from one time to another. The long life span can be up to 11 months, and the short life span is only about 2-3 weeks. During this period, the males are busy looking for females to mate, and females are looking for hosts to lay eggs, and they are active and active, so they must take in the nutrients from the natural world.

in order to successfully complete their sacred mission of propagating seeds and generations.

Butterflies are not insects that specialize in detecting flowers and absorbing nectar. Due to the different species, they feed on very different objects, and most of them are exclusively feeders. For example, some species not only suck nectar, but also suck the nectar of certain plants; Some butterflies do not suck nectar and eat the sap of other rotten fruits or bored trees, and even the feces of humans, animals, birds and beasts, which shows that butterflies have a wide range of diets.

It needs to collect nectar, increase nutrients, and prepare for reproduction to the next generation.

The butterfly flew to the trunk of the tree, and after a while, the wings fanned and fell on the flowers