The larvae of the bean moth, also known as bean bugs, bean dan, is a kind of eating bean leaves, drinking manna for a living, in the natural non-toxic, non-polluting state of the growth of insects, it is high in protein, low in fat, with the effect of warming the stomach. It has a graceful body shape, similar to the silkworm. Adults are about 5 centimeters long, tender green, with darker head color and tail horns. From the first section of the abdomen, there are seven pairs of white lines on both sides. It jeopardizes the bean leaves, rodding into holes, and when the plant is serious, it becomes light stalks, and can't bear pods.