Velocipedidae

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Velocipedidae
Systematics
Class : Insects (Insecta)
Order : Schnabelkerfe (Hemiptera)
Subordination : Bed bugs (heteroptera)
Partial order : Cimicomorpha
Superfamily : Velocipedoidea
Family : Velocipedidae
Scientific name
Velocipedidae
Bergroth , 1891

The Velocipedidae are a family of bugs (Heteroptera) in the suborder Cimicomorpha . At least 31 species in 3 genera are known of them.

features

The rather small bugs are 6 to 12.4 millimeters long and have a rather flattened, oval to broadly oval body. They are brown to blackish in color and mostly matt. They are often provided with a slightly silver-gray shimmer due to a dense and very fine structure of their body surface. On the pronotum , scutellum and the hemielytras, with the exception of the membranes, they are numerous, deeply punctured, the punctures usually having a blackish or black-brown halo. On the hemielytres these dots are partly arranged in rows that follow the veining of the wing . The width of the bugs including hemielytres is at least half the length of the body including hemielytres but without the head. The conical head is long and directed forward. The compound eyes emerge; Pointed eyes ( ocelli ) are formed, but are absent in the nymphs . The antennae are four-limbed, the second limb being the longest and bearing a tuft of fine setae distally . The rostrum is very long. It is four-part, but appears three-part due to the stunted first segment. The penultimate link is the longest. The pronotum is trapezoidal and has a well developed, uninterrupted collar. In the hemielytres, the front part of the exocorium extends into the broad embolium. The membrane has four basal cells, three of which are closed, and many longitudinal arteries that arise from the distal area of ​​the cells. The long and slender legs are designed as walking legs and, with the exception of a few small tubercles on the thighs ( femora ) of the middle legs of males of the genus Costomedes, do not have any extensions. The long and slender rails ( tibia ) lack the spongy fossulae (specialized hairy structures that serve to hold on). The tarsi are tripartite, with the first term being the smallest. The pretarsi have simple claws, the parempodia are thread-shaped. The metathorax has paired openings of scent glands on both sides of the metasternum at the border between the sternum and pleuron , the drainage and evaporation area of ​​which lies on the metapleuron. The eighth segment of the abdomen in males is well developed, with the pygophores and paramers being symmetrical. The genital apparatus of the females is of the lance-shaped construction ("laciniate type").

The monophyly of the family is based on several synapomorphies . These include the greatly expanded exocoirum of the forewings; Pronotum, shield, clavus and corium, which are heavily dotted; the venation of the membrane of the hemielytra, which includes four basal cells, three of which are closed; the unique "velocipediform" antennae with the third and fourth flagellated segments and the unique shape of the rostrum, which has a receding first and an extremely long third segment and a very short fourth segment.

Occurrence and habitat

The family is common in the tropics of the Old World. The bugs occur from east India and Nepal to the Solomon Islands and from south China and the north of the Philippines to Java . However, the distribution is divided into two very separate areas by the Wallace Line . The eastern part of the distribution (genus Costomedes ) runs east of Luzon and Mindoro in the Philippines, but could not include the remaining parts of the Philippines, where the animals could not (yet) be detected. The eastern distribution includes Seram , New Guinea including Waigeo , Yapen and the Louisiade Archipelago , Bismarck Archipelago, and the Solomon Islands. The distribution is not (yet) known from the northern parts of Australia. The western part with the genera Scotomedes and Bloeteomedes comprises the eastern continental part of Asia, including Sikkim , southern China, the Malay Peninsula , Sumatra , Java, Bali , Borneo and Luzon. The western distribution has not (yet) been proven in Hainan , the southern Philippines, Halmahera , Buru , Sulawesi and the Lesser Sunda Islands east of Bali.

The vertical distribution is evidently different depending on the species, since the respective species can be assigned to different levels of altitude, even if the predominant evidence from light catches leads to a certain source of error, as animals can be attracted from a certain distance. Representatives of the family can be found in New Guinea, for example, from the plains up to 2700 to 2800 meters above sea level.

It is hardly known which habitats the representatives of the Velocipedidae colonize. It seems that they are forest dwellers, especially at higher altitudes. At least individual finds have been identified from the underside of fungal dead wood on the forest floor. The top of the body of the bedbugs is often soiled, with organic particles often (sometimes only) a film of a dried yellowish-white substance being found, which may be a secretion released by the animals. The organic particles presumably serve as camouflage and, on closer examination, could provide information about the populated habitats. From all this it is assumed that the bugs live in or on the forest floor.

Way of life

Almost nothing is known about the family's way of life. Based on the construction of the mouthparts, a predatory way of life is assumed, whereby the elongated head and the very long and stretchable rostrum suggest a certain application of this. The structure of the head is similar to that of the triatominae , which suck blood through feathers and fur. The absence of the spongy fossulae on the rails, which otherwise occurs in almost all predatory groups of bugs, could mean that the front legs play no role in catching and / or fixing the prey. The construction could therefore mean that the bugs feed on deeper-lying food or prey, for example in soil, dung, holes, dead wood, fur, etc. However, no observations have been made so far. From the rest of the bugs' anatomy, it is obvious that the animals are good runners and fliers. Most of the known specimens, especially those of the genus Costomedes , were caught in the light.

What is striking about many species is that they often carry a large number of phoretic mites of at least two types on their bodies. These are probably deutonymphs from species of the mite cohorts Uropodina and Astigmatina . This feature is so noticeable in this family of bugs that a function in their way of life is assumed. This is also confirmed by the fact that at least in some species of the genus Costomedes there is a space between the posterior lobe of the pronotum and the underlying mesoscutum , where the mites often stay. You can get there on either side of each of the indentations for the hips ( coxes ) through a narrow passage along the first large stigma up to this space. The mites are also often found in the passageways. If one assumes that these body modifications represent an adaptation, one could suspect a symbiosis . The mites could be beneficial to the bed bugs in their habitat.

Taxonomy and systematics

Carl Stål described Scotomedes ater in 1873 , the first species and genus ( Scotomedes ) of the group, but placed it in the subfamily "Coriscina" (Nabinae) of the sickle bug family (Nabidae). 1891 followed the first description of Velocipeda prisca by Ernst Evald Bergroth . Bergroth apparently overlooked the previous description of Stål, as he also described a new subfamily, the Velocipedinae, for the new species and genus he described, which he placed in the family of the bank bug (Saldidae). In 1903 Breddin described a third species with Velocipeda minor . The fourth species, Godefridus alienus , was described by Distant in 1904 and, in ignorance of the closely related species already described, first placed it in the subfamily Apiomerinae of the predatory bugs (Reduviidae), later the genus Godefridus, however, synonymized with Velocipeda . The fifth species was described by Reuter in 1908 as Velocipeda biguttulata . It was not until 1945 that Blöte recognized that Stål's genus Scotomedes ater and Velocipeda biguttulata were synonymous and placed Scotomedes in the new subfamily Scotomedinae of sickle bugs. The genus Bloeteomedes was finally first described by van Doesburg in 1970. The union of Scotomedes , Velocipeda and Bloeteomedes in a common family Velocipedidae took place relatively very late. In a paper from 1991 Schuh & Štys assumed that the family split off from the rest of the Cimicomorpha earlier than the sickle bugs and placed the family in their own superfamily Velocipedoidea .

The Velocipedidae are undoubtedly closely related to the sickle bugs, but have not only many similarities but also clear differences. They have a well-developed cuneus and a fully developed eighth abdominal segment in the males. The sickle bugs are active predators and the entire front body, such as the mouthparts and the first two pairs of legs, are adapted to them. The Velocipedidae lack these characteristics. If the presumed predatory way of life also applies to them, they are more likely to be ambulance hunters. It is therefore assumed that the Velocipedidae did not develop from the sickle bugs, but only had a common ancestor.

The family consists of two clearly related groups in which several individual characteristics are different without exception or transitions. The first, western group includes the two genera Scotomedes and Bloeteomedes , the second, eastern group the genus Costomedes . The first group is probably monophyletic due to the macroscopic cells on the second antennae and the yellow point in front of the exocorium . The monophyly of the second group is based on the cuneus elongated at the rear, the thorn-proof thighs ( femora ) of the middle legs in the males , the missing setae on the antennae, the missing point on the exocorium and the wide pygophore at the back. From this the following cladogram can be derived for the family :

 Velocipedidae 
 western group 

Scotomedes


   

Bloeteomedes



 eastern group 

Costomedes



The following genera and species are known so far:

supporting documents

Individual evidence

  1. ↑ a b c d e f g h i j k P. H. van Doesburg: A taxonomic revision of the family Velocipedidae Bergroth, 1891 (Insecta: Heteroptera). In: Zoologische Verhandelingen. 347, 2004, pp. 5-110.
  2. ↑ a b c Petr Kemt, Petr Šrámek: First record of the family Velocipedidae (Heteroptera: Cimicomorpha) from Nepal. In: Acta Entomologica Musei Nationalis Pragae. 45, 2005, pp. 17-18.
  3. ^ A b P. H. van Doesburg, T. Ishikawa: A new species of Scotomedes from Taiwan (Insecta: Heteroptera: Velocipedidae). In: Zoologische Mededelingen. 82, No. 25, 2008, pp. 261-266.
  4. ↑ Christiane Weirauch: Hairy attachment structures in Reduviidae (Cimicomorpha, Heteroptera), with observations on the fossula spongiosa in some other Cimicomorpha. In: Zoologischer Anzeiger - A Journal of Comparative Zoology. 246, No. 3, 2007, pp. 155-175, doi : 10.1016 / j.jcz.2007.03.003 .