Millipede (Maripes, scientific name: Diplopoda) is a general term for arthropods belonging to the Myriapoda millipede. There are many thin, short legs. It is similar to the centipede, but differs in various points such as the position of the reproductive ostium, the mode of development, and the number of peduncles per segment. Centipedes are carnivorous, whereas millipedes are humus and do not have poisonous jaws. The English name Millipede is derived from the Latin word millipede. It is the earliest arthropod with an existing terrestrial life history to advance to land.
The body is divided into dozens of nodes. There are no legs in the first torso, one pair in each of the 2-4 torso, and two pairs of legs behind it. Therefore, it is also called a double leg. In addition, the head has a pair of small antennae consisting of 8 segments, and the presence and number of eyes vary depending on the type (not so related to classification).
Except for some, it has a hard exoskeleton and an elongated body. The abdomen is a little flat, but the back surface varies from those like Julida and Futomaruyas, which have a large bulge and a nearly circular cross section, to those like flat Polydesmida and Hiratayas.
Millipedes are not as elongated as other millipedes, and because of their soft body and bristles on the back and tail, they look like larvae of the skin beetle.
The largest species in Japan is Yaeyama Maruyasude, which is about 7 cm long. The largest species in the world are large species from Africa such as the African millipede and the Tanzania millipede, which can reach up to 30 cm.
It is a soil animal that moves slower than centipedes and is mainly eaten by plant remains. Kishayasude and others use organic matter in mineral soil as a nutrient source. However, cave species may eat bat droppings and carcasses. Many species secrete liquid and gaseous stimulants from the venom glands on the body surface. Many of them curl up when stimulated. Normally, they are spirally formed into a disk, but the Pill millipede and Pill millipede are spherical.
Relationship with human life
Millipedes are generally considered pests, but they have many false accusations and are typical unpleasant pests. Flocks such as the unpleasant appearance, the offensive odor when stepped on, and the periodic mass outbreak of Obibabayasde Parafontaria laminata (Kishayasde Parafontaria laminata armigera is now treated as a synonym of this species). The reason is that when a train crawls on a railroad track and is trampled by a train wheel, the body fluid causes the train to slip. In the fall of 1976 (Showa 51), it occurred in large numbers along the Koumi Line, Yatsugatake, Utsukushigahara, Kirigamine, and around Matsumoto City. Since the train was suspended on the Koumi Line, 130 to 170 Obibabayasude (Kishayasude) were confirmed per 1 m on the rail.
If sealed, it may die from its own odor. The odor is often released outside the body as a threat to the enemy, mainly when it feels dangerous. When attacked by a foreign enemy, unlike a centipede, it does not actively bite with its jaw, but curls up and defends itself. For most species, touching them does not cause any real harm.
Only some species of millipedes occur in and around houses, and many millipedes live in forests. The larvae are mainly soil dwellers in the forest and are said to have a soil tillage effect, and the adults are also said to contribute to the decomposition of leaf litter. In this way, it is thought that it plays a certain role in soil formation, and it is essential to be a decomposer in the natural world from the viewpoint of food habits and ecology.