By Wayne Hsu (taken from GATEPOST, May 1998)

What are beetles?
Beetles are insects in the order Coleoptera. Like all insects, they have three pairs of legs. Beetles pass through four stages in their life cycle: egg, larva, pupa, and adult. Larvae of scarab beetles, called grubs, are most often seen by gardeners. Grubs eat underground compost and appear as soft, white worms usually curved in a "C" shape. In many third-world countries, grubs form a nutritional part of peoples' diets. Larvae of stag beetles eat decomposing wood and may be found in rotting tree stumps and branches. These beetles are beneficial since they help break down fallen trees in the forest. Larva of fireflies, on the other hand, live in clean streams or on the humid forest floor. Adult beetles do not resemble their larva; most have hardened forewings called elytra, which protects the beetle*s hind wings and body. The following describes some common species of beetles:

Scarab Beetles (Scarabaeidae)
This is the largest family of beetles and also the most commonly seen in Taiwan. The green beetles often found at night under street lamps of Yangmingshan are scarab beetles. Many of the largest beetles in the world are scarabs, such as the Atlas Beetles of Southeast Asia, the Hercules Beetles of Central America, and the Goliath Beetles of Africa. Many types of scarab beetles feed on tree sap, so they often gather in large numbers where sap is flowing out tree trunks. The largest scarab beetle in Taiwan is the Formosan Long-armed Scarab (Cheirotonus macleayi formosanus) which lives in undisturbed forests in the mountain ranges of Taiwan, and it occasionally appears under street lamps of mountain settlements. The male of this species has incredibly long forelegs, about twice the length of its body, a metallic greenish-purple thorax, and black forewings speckled with orange spots. The population of this species has declined due to over-development of forests, so this beetle has been granted protection by the government; it is against the law to collect them. Another interesting scarab beetle is the Japanese Rhinoceros Beetle (Allomyrina dichotomus), common in forests at lower elevations. This species is also strongly attracted to light sources at night, so it can easily be found under street lamps on mountain roads. A male rhinoceros beetle often guards its food source aggressively and will pick a fight with any other male that attempts take over his feeding spot.

Stag Beetles (Lucanidae)
Male stag beetles have huge mandibles, or jaws, that resemble the antlers of a stag (male deer). Another characteristic of stag beetles is their jointed, L-shaped elbowed antenna. While stag beetles may look fierce, they are actually quite harmless if handled carefully; their pinch may be painful but rarely draws blood. There are nearly fifty species of stag beetles in Taiwan, and they all live in forests. Different species of stag beetles have differently shaped mandibles. Stag beetles also come in many shades of colors, ranging from orange to copper to black. Like rhinoceros beetles, most species can be attracted to bright street lamps at night. They may also be found feeding on tree sap flowing out of trunks, where males use their pinchers to guard their food against other beetles. Unlike males, female stag beetles have small mandibles that are used to bite through rotting tree trunks where they lay their eggs; their pinchers are strong and can give painful bites.

Long-horn Beetles (Cerambycidae)
Long-horn beetles are named for their long antennas. Many species exist, from colorful to dull, and large to small. Anoplophora macularia is a type of long-horn beetle common in citrus orchards, is attracted to street lamps at night, and is black with white spots on its wing covers. One of the larger attractive species but rather uncommon is Batocera lineolata, which can be found at higher elevations.

Click Beetles (Elateridae) and Jewel Beetles (Buprestidae)
Click beetles are entertaining to watch because when they are disturbed, they freeze and drop to the ground, and they lie motionless on their backs waiting for the predator to go away. When the beetle feels safe, it "clicks" and sails through the air where it does a quick flip, lands on its belly, and scurries to safety. While most species of click beetles look rather drab, an exception is the colorful Campsosternus gemma, a protected species. Jewel beetles are closely related to click beetles, but they do not have the ability to click when disturbed. There are also many species of jewel beetles, but the most beautiful is Chrysochroa fulgidissima, once used to make jewelry but now also a protected species.

How to find beetles
While beetles may be found nearly anywhere, even in the heart of great cities, most of the species described above live only in forests. People living in mountainous areas therefore may be lucky enough to have beetles flying near their porch lights after dark. Other people may need to travel farther to search for them. In general, adult beetles are most abundant during the warmer months, from early summer until autumn. During this time, look carefully when you go hiking and you may find beetles on tree trunks, leaves, or on the ground. Bright sources of light near the forest, such as street lamps, will often attract various species of beetles which gather there at night.

Keeping beetles as pets
Many types of beetles are suitable for keeping in captivity and can be valuable educational pets. Rhinoceros beetles and stag beetles are the easiest to keep alive. These beetles may be kept in a small container with a tight lid that has holes punched in it. The container should be filled with soil that should be kept slightly damp. Feed the beetle a small piece of juicy fruit that needs to be replaced occasionally. Adult rhinoceros and stag beetles live for only a couple months, so they are not extremely difficult to keep alive, even for a small child. If you have a pair of rhinoceros beetles, keep them in a bigger container with more soil and the female may lay eggs in the soil. For people who have the time and patience, the eggs can then be reared into another generation of beetles. The larvae requires only that the soil be kept damp and changed every now and then.

Beetles are the most diverse group of animals in the world, and their variety, shapes, sizes, and colors have never ceased to amaze people. Fine and rare species are often highly prized by collectors and museums. Colorful species are sometimes made into expensive jewelry. Many of the large attractive species find their way into the exotic pet trade; Japan commercially breeds beetles for pets and collections. Like many other wonders of nature, however, beetles are now suffering from problems caused by habitat destruction and over-collecting. To prevent them from becoming extinct, many governments grant protection to rare species of beetles. Nevertheless, as development and habitat destruction continue, many species of wonderful beetles may be extinct before we even realize their existence.