|Coenagrion is a genus of damselfly
in family Coenagrionidae, commonly called the Eurasian Bluets (although
three species are found in North America, C. angulatum, C. interrogatum,
and C. resolutum).
Coenagrion hastulatum (Charpentier,
1825), the Northern Damselfly or Spearhead Bluet, is widespread and common
in northern Eurasia but is restricted to elevated or bog-like sites towards
the west and south. In Britain, it is confined to a few small lochans in
Scotland. The specific part of the scientific name, hastulatum, from the
Latin hastula (small spear) is because of the distinctive markings on the
second segment of the abdomen that resembles a spear.
Coenagrion hastulatum is a smallish
but fairly robust, black-and-blue species. It is 31-33 mm long. In the
male, S2 has a rather variable, spear-head shaped spot linked rather like
the cards "Spades" symbol. S8 and S9 are blue except for 2 small black
spots on S9. The females are black and green, and are clear green from
the side but mostly black from above. Coenagrion hastulatum's most distinguishing
features include the spearhead-shaped mark on the male's S2 (which gives
the species its scientific and common names) and the line which connects
the fairly narrow, pear-shaped postocular spots (a feature which distinguishes
it from its congener C. lunulatum).
This species is easily confused with
the other members of the genus Coenagrion and with the Common Blue Damselfly
Enallagma cyathigerum. Look at S2 (on the males) for distinguishing characters.
Northern Damselfly is a weak flyer and has a very restricted range. The
females can be particularly tricky to distinguish apart.
Coenagrion hastulatum is native to
Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Italy, Latvia, Lithuania,
Montenegro, Netherlands, Norway, Russian Federation, Serbia (Serbia), Ukraine,
United Kingdom. It has experienced declines in parts of its central European
range but it is widespread and abundant in northern Eurasia. There are
a number of ongoing threats that will require the species to be monitored
and studies are in place to do this. Therefore, it is accessed by IUCN
Red List as Least Concern.