Water treader
Mesovelia hackeri
The Hüftwasserläufer ( Mesoveliidae ) are a cosmopolitan family of bugs within the partial order Gerromorpha. There are nearly 50 known species in 11 genera. In Europe, three species occur.
Features
The animals are 1.2 to 4.2 millimeters long and are highly variable in their appearance, as well as the development of their wings. Most species are greenish to brown and have long legs with an elongated, egg-shaped body. With Cryptovelia terrestris family comprises one of the smallest species of bugs at all. Their compound eyes consist of only three to four individual ommatidia.
Her head is large and elongated and extends well above the compound eyes out. The micro-and Makrobehaarung is limited to the head and the thorax Prosternum. Simple eyes ( ocelli ) are formed, however, absent in apteren ( wingless ) imagines. The antennae are four members, the labium tripartite. The maxillae are strongly serrated. The pronotum is truncated rear. Winged individuals have a visible, enlarged, two-piece tag ( scutellum ). In wingless individuals is lacking. The scent glands on the metathorax are openings on Metasternum ( Omphalium ). The tarsi are tripartite, the first segment is very small. The claws are apically. The front wings are built up evenly; the clavus and the membrane have a similar surface texture. The membrane missing wing veins. The dermis is composed of two or three closed cells. The ovipositor of the female is well developed. It is serrated and fringed. The dorsal scent gland openings on the third or fourth Tergum the nymphs are regressed. The aedeagus has a specially designed pump for ejaculation and a pear-shaped part. The paramere are symmetrical.
The family is distributed worldwide. The genus Mesovelia is widespread and includes a few species that have a very large area of distribution. All other species are confined to a restricted area of distribution and show as a whole a more scattered distribution. This and the basal position within the Gerromorpha suggest that the group is very old.
Way of life
The family settled preferably standing waters and there especially the banks of the waters or the environment of plants or floating objects in the water. There are also species that live on drenched moss and water-wet rocks, in caves, or in wet slime molds. In addition, there are also species that have evolved and off terrestrial life from the water in the leaf litter.
The bugs feed predatory or scavengers; often dead or injured animals on the water surface. You suck on arthropods, including ostracods and larvae and pupae of mosquitoes. The females pierce their eggs into the tissue of aquatic plants. A female can lay more than 100 eggs. In very cold climates, winter eggs. Under warmer conditions can be active Imagines encounter throughout the year. The animals are on the free water surface very nimble, and they mostly reside in plants and have a more hidden way of life.
Taxonomy and systematics
The family is the most primitive part of the order Gerromorpha. It was historically close to the sickle bugs ( Nabidae ) and assassin bugs ( Reduviidae ) provided and arranged by Sahlberg 1920 within the partial order Gerromorpha.
The following subfamilies are counted in the family:
- Subfamily Mesoveliinae Genus Austrovelia (2 types; Australia, New Caledonia)
- Cavaticovelia genus ( 1 species; Hawaii)
- Cryptovelia genus ( 1 species; Lower Amazon Basin )
- Genus Darwinivelia (2 types; South America, the Galapagos Islands)
- Mesovelia genus (about 25 species, worldwide)
- Mniovelia genus ( 1 species; New Zealand)
- Nereivelia genus ( 1 species; Singapore, Thailand)
- Genus Phrynovelia (3 types, Neuguines, New Caledonia )
- Genus Speovelia (2 types; Mexico, Japan )
- Subfamily Madeoveliinae Genus Mesoveloidea (2 types; tropical America)
- Madeovelia genus ( 1 species, Guinea )
In Europe, the following species occur; Mesovelia furcata also in Central Europe.
- Mesovelia furcata Mulsant & Rey, 1852
- Mesovelia thermalis Horvath, 1915
- Mesovelia vittigera Horvath, 1895