The Black ploščec (Libellula fulva) is characteristically colored and is difficult to confuse with any other species. Adults are typically 42 to 45 mm long, with a wingspan of about 7 cm.
Before reaching sexual maturity, the juvenile male has brown-orange eyes, a vividly orange body, and along the midline of the dorsal side of the abdomen a broad black stripe extends. The body of the adult male then darkens, and his eyes become glassy – the thorax, the facial part, and the last three segments of the abdomen become black, the central part of the abdomen becomes bluish gray, and the eyes become bluish gray.
For the genus, the characteristic black patch at the base of the wings is, in both sexes of this species, limited to the hind pair; at the base of the forewings there is only a black line. Adult females are colored similarly to immature males, only their eyes are black-gray. For females, dark wing tips are characteristic, which may also be present in males. With age, females darken as well; the orange color of their body is replaced by dark brown – at that point we will most easily recognize the female by the dark wing tips.
This species lives in bodies of water with a weak current, whose banks are richly overgrown with tall aquatic vegetation such as trst, rogoz, jezerski biček, ježek or vodna perunika. It prefers abandoned and therefore densely overgrown canals and drainage ditches, where as a larva it lives in organic debris that accumulates among the stems of plants.
This is an early-summer species. Adults can appear as early as the end of April, but most of the larvae metamorphose in May and June, and solitary black ploščci can still be found in early August. Also the males of this species perch in exposed spots from which they have a good view of activity around them and launch themselves like arrows at unwanted intruders.
In Slovenia the species is listed among endangered dragonfly species. It is classified as a vulnerable species (V), which is primarily threatened by excessive cleaning of canals and jarkov and thereby the destruction of the larvae's habitat.
