Fireflies, a common sight in agricultural society of old, have been greatly reduced in number due to environmental change. In order to raise understanding and appreciation of these tiny fairies that represent "light" and "hope," as well as to build a solid loving foundation for firefly conservation so as to protect these adorable creatures and make sure that later generations will be able to enjoy this precious natural resource, Chunghwa Post is issuing a set of four stamps on fireflies, each of which will have a denomination of NT$5.00. The featured firefly species include Pyrocoelia analis, Diaphanes citrinus, Diaphanes niveus and Diaphanes formosus. The designs of the stamps follow:(1) Pyrocoelia analis: This species is more drought-tolerant than the others. It is the most common firefly found in the plains during spring and fall. They can often be seen in parks and near bushes along mountain roads where there is no light pollution. It is a magnificent sight when they swarm. (2) Diaphanes citrinus: This species emerges in fall, and occasionally at the height of summer. Because its back is all orange, it is called "orange firefly" in Chinese. Males also emit a continuous glow when flying, but they do not swarm. Mainly, it is frequently seen in mountainous areas of low to middle elevation.(3) Diaphanes niveus: This is an endemic species of Taiwan that can be found from October to December each year. The backs of the males are creamy white and are mostly seen in mountainous areas during winter. Consequently, they are called "snow fireflies" in Chinese. In some areas they are numerous, and their swarming is well worth observing.(4) Diaphanes formosus: This species can be found in spring and summer in many mountainous areas of low to middle elevation. They do not swarm and they are attracted to light.