Leucorrhinia caudalis
Leucorrhinia caudalis (Charpentier, 1840)
Local names: Lilypad whiteface, Zierliche Moosjungfer, Sierlijke witsnuitlibel, Leucorrhine à large queue, Bred kärrtrollslända
Species Information
Description
This species looks rather short, plumped and wide-winged. Males often likes to perch on lilypads, hence the english common name. Leucorrhinia they have black patches at the base of the hind wings and a visibly white frons.
Unlike most other species of Leucorrhinia the mature males are dark with very light-blue pruinosity and no red spots on the abdomen (older individuals can get red markings on the side of the thorax). Both males and females have white appendages. These characteristics it share only with L. albifrons but compared to that species L. caudalis has a more clubbed abdomen, S7-S8 is broadest. The male pterostigma are white on the upper surface and dark only on the lower surface, whereas L. albifrons has dark pterostigma on both sides. Like all
The immature males and females of L. caudalis has yellow spots and look similar to all females of Leucorrhinia. The clubbed shape of the abdomen and the whitish appendages are still telling that these are L. caudalis. The spots on the abdomen are larger than those of L. albifrons and often those on S3 and S4 are merged together. Unlike L. albifrons the labium is all-dark. Female pterostigma are dark. Older females can get very dark and even get some pruinosity.
The width of the abdomen can vary from a wide abdomen with not so marked club to narrow abdomens with a very noticeable club. Male pterostigma colouring can vary some and the dark underside can in some angles of observation confuse the observer.
Size
Habitat
Leucorrhinia caudalis is most frequently found at mesotrophic to weakly eutrophic lakes or bogs with a rich submerged vegetation often including hornworts, watermilfoil or Stoneworts. The species is often found at places with floating hydrophytes such as Waterlily on which males tend to perch; however it also occurs at waters in which floating hydrophytes are largely absent. Most waters where the species occur are relatively deep (1-3 m) and have clear water. The banks are steep or shallow and are usually unshaded despite most populations being found in forested or semi-forested areas. Such habitats include lakes and oxbows fed with phreatic water, fishponds, peat excavations, gravel pits and lakes in quarries, mostly in lowland (rarely above 500 m). This species is much less sensitive to fish predation than the other Leucorrhinia thanks to their well-developed mid-dorsal spines, which increase their survival chances in attacks from behind.
Distribution
Leucorrhinia caudalis has a reasonably large European range but is only regionally common. The core of its European range includes northern France and north-east Germany to the Baltic states and southern Fennoscandia. Few records are available from European Russia, Belarus and Ukraine but this probably reflects a lack of surveys in this region, with the species expected to be present at many more sites in these countries than are previously known. In central Europe it is rare and populations are confined to the lower Alpine region and the Pannonian lowlands. In southeast Europe records are scattered along the Danube, Tisza and Drava rivers, the latter forming the border between Hungary and Croatia. Further south only isolated populations are known from Croatia and the north of Serbia. In western Europe the species is well established from western Germany along the Rhine to the Atlantic coast in France, reaching an area running from northern Aquitaine to southern Brittany.
Flight Period
Mid-May to the beginning of August, with peak in June.
Behavior
Most easily found by looking for territorial males. These sit open and exposed on floating vegetation, preferably lilypads but also pontoons, jettys and other floating devices. Immature and female individuals can be found a bit away from water in sunlit sheltered areas, like edge zones, glades, clearings between bushes or larger trees. They often perch low in vegetation or directly on the ground.
Eggs are oviposited by the female without male company but sometimes he stick around and guard her. Larvae development is probably three years in the north. Exuviae can be found in direct connection to water on vegetation a couple of decimeter up.
Conservation Status
Similar Species
Leucorrhinia albifrons
External Links
Genus: Leucorrhinia
Leucorrhinia is a genus of dragonfly in the family Libellulidae. They are commonly called whitefaces because of their distinctive pale frons.
Identification
Easily distinguished, even from afar, by their bright white face that is contrasting with their largely black body. This feature is combined with unique wings, having dark spots at the hindwing bases, only 7-8 (rarely 9) forewing antenodal cross-veins and notably short, rectangular pterostigmas. The abdomen is predominantly black, with a single series of pale dorsal spots that either turn deep red in mature males or disappear whilst the abdomen becomes grey pruinose at its base.
Separation from other genera
Other libellulids have coloured faces, although this may be poorly developed in young individuals, and in most of those genera pale colours predominate on the abdomen. Males developing pruinosity (e.g. Orthetrum, Libellula) tend to have this on more than half the abdomen, but the distinction may be difficult in old and worn pruinose Leucorrhinia males. The only largely black libellulid occurring widely with Leucorrhinia species is Sympetrum danae. The smallest species, L. dubia in particular, may be confused with it when viewed from a distance; S. danae has a yellow to black face, and at most a yellow hindwing base. Finally, the white-faced North American vagrant Pachydiplax longipennis may recall a Leucorrhinia species, but it is only likely to appear on the Atlantic seaboard.
Separation of the species
Five species occur in our area. All increase in abundance towards the north-east, ranging deeply into Siberia. Another seven inhabit North America. Our species can easily be separated into two groups. Two species have white appendages and males that become dark, with grey pruinosity at the abdomen base. Three others have dark appendages and develop deep red markings but no pruinosity. Note that the species in these groups often occur together. The white appendages are easily seen from a distance. To identify species, especially the red-spotted ones, examination in the hand might be helpful. The male's hamule and female's vulvar scale rule out all confusion. Young individuals of all species are black with yellowish spots, and can only be separated safely by close examination, and by also referring to the pattern of spots.
| Group | species | |
|---|---|---|
| Group 1 | L. albifrons, L. caudalis | has white appendages |
| Group 2 | L. pectoralis, L. dubia, L. rubicunda | has dark appendages |
Behaviour
All species have an erratic flight, especially the smaller red-marked species, which can often be seen dancing over bogs and fens. The larger, pruinose species fly more slowly, often over open water or even among the trees surrounding a breeding site. Females of all species may oviposit alone, or are guarded by the male flying or perching nearby.
Family: Libellulidae
The skimmers or perchers and their relatives form the Libellulidae, the largest dragonfly family in the world. It is sometimes considered to contain the Corduliidae as the subfamily Corduliinae and the Macromiidae as the subfamily Macromiinae. Even if these are excluded, there still remains a family of over 1000 species. With nearly worldwide distribution, these are almost certainly the most often seen of all dragonflies.
The genus Libellula is mostly New World, but also has one of the few endangered odonates from Japan: Libellula angelina. Many of the members of this genus are brightly colored or have banded wings. The related genus Plathemis includes the whitetails. The genus Celithemis contains several brightly marked species in the southern United States. Members of the genus Sympetrum are called darters (or meadowhawks in North America) and are found throughout most of the world, except Australia. Several Southern Hemisphere species in the genera Trithemis and Zenithoptera are especially beautiful. Other common genera include Tramea and Pantala.
The libellulids have stout-bodied larvae with the lower lip or labium developed into a mask over the lower part of the face.
The family name may have been derived from the Latin libella which means booklet.