DIPLURANS: DipluraNO COMMON NAME (Holjapyx diversiunguis): SPECIES ACCOUNT
Diplurans have three distinct body regions (head; thorax, or midsection; and abdomen), no wings, and six legs, but they are not considered true insects. Diplurans form a group closely related to insects that includes proturans (order Protura) and springtails (order Collembola). All of these animals have chewing mouthparts inside a special pocket in their head.
Diplurans are long, slender, and cylindrical or slightly flattened animals that are 0.12 to 1.97 inches (3 to 50 millimeters) in length. They are usually white or pale yellow and are often slightly transparent, or see-through. Their bodies are covered with hairlike structures. Diplurans have no eyes, but their antennae (an-TEH-nee), or feelers, are bristling with sensory hairs. The abdomen has ten segments and is tipped with a pair of threadlike or pincherlike appendages, or limblike structures. Most of the segments have pairs of small leglike structures underneath that are used to support the long abdomen.
Diplurans are widely distributed throughout the world.
Diplurans live in the soil and are found in moist habitats under rocks, logs, leaf litter, and tree bark. Some species live in caves.
Diplurans eat both plant material and animal tissues. They feed on living and dead small, soft-bodied mites, worms, symphylans (sihm-FIE-luhns) other diplurans, and insects. They also eat funguses, living plants, and decaying vegetation.
BEHAVIOR AND REPRODUCTION
Some species burrow in loose soil, making wormlike movements with their long, slender bodies. They are also capable runners on the surface of the ground. Other species have powerful legs for pushing their way into cracks and pockets in the soil, but they are very poor runners. Many species use their mouthparts to help them dig through the soil.
Diplurans locate their food sources, or prey, with their antennae, or feelers, and stalk them until they are within striking distance. Species that have pincherlike structures at the tip of the abdomen sometimes use them to capture prey but more typically employ them for defense. Diplurans with long, flexible, taillike structures quickly lose them if they are grasped by a predator (PREH-duh-ter), hunting them for food. This allows the dipluran to escape.
Male diplurans attach sperm packets to the soil. Females search for these sperm packets and collect them to fertilize their eggs. They lay their eggs on stalks in small clutches, or groups, on leaf litter or in small cavities in the soil. In some species the female protects her eggs by wrapping her body around them. She will stay with them for a short time after they hatch.
DIPLURANS ON THE EDGE?
Although no diplurans are recognized to be in danger of extinction, it is still possible that some species have had their populations reduced or eliminated altogether. Scientists know so little about these animals that the destruction of their habitats would wipe them out forever and we would never know it. However, some species appear to be able to deal with habitat destruction. For example, several species are known to live and reproduce successfully within the city limits of Vienna, Austria.
Young diplurans, or larvae (LAR-vee), look like small versions of the adults. They are unable to feed until after they shed their external skeleton, or molt, for the first time. Diplurans reach adulthood after their second molt. Adults live as long as two years and continue to grow and molt for their entire lives. Continued molting allows them to replace broken or worn-out legs and other body parts.
DIPLURANS AND PEOPLE
A few diplurans cause minor damage to garden vegetables by eating them, but most species do not affect people in any way.
No species of diplurans is threatened or endangered.
Physical characteristics: This species measures 0.2 to 0.3 inches (6 to 8 millimeters) and can only be identified by looking at the hair-like structures on the body and the abdomen under a microscope. The body is pale yellow, while the last abdominal segment and pincher-like structures are dark brown. The antennae have twenty-six segments. Each half of the pinchers has a distinctive toothlike projection.
Geographic range: These diplurans are found in central California. They are distributed from the Pacific coast east to the crest of the Sierra Nevada mountains.
Habitat: This species lives in the soil and is often found under rocks and wet leaf litter.
Diet: Nothing is known about the food preferences of this animal.
Behavior and reproduction: This dipluran has been found down in the soil to depths of 30 inches (76 centimeters).
A female was found with eight small larvae, suggesting that she not only looks after her young, but that she probably stands guard over the eggs.
Holijapyx diversiunguis and people: This species has no direct impact on people or their activities.
Conservation status: This species is not threatened or endangered. ∎
FOR MORE INFORMATION
"Diplura." Tree of Life Web Project. http://tolweb.org/tree?group=Diplura&contgroup=Hexapoda (accessed on September 1, 2004).
"Entognathous Hexapods: Diplura." Ecowatch. http://www.ento.csiro.au/Ecowatch/Hexapods/diplura.htm (accessed on September 1, 2004).