Tthe existence of dark colour form of male in Sympetrum meridionale (Sél.) (Anisoptera: Libellulidae)

According to the extent of black on the thorax and legs it is possible to identify several groups within Sympetrum species. S. meridionale belongs to the group where the black on the thoracic sutures is much reduced and limited only to certain parts on the legs. In typically coloured specimens (Fig. I, according to caught specimens) there is a black spot along the superior third of the humeral suture and also on the inferior of the mesepimeron, where the black spot protracts toward spiracle, although the spot projection does not reach the mesometapleural suture. Only the inferior part of mesinfraepistemum is black. There is a smaller spot on the inferior of mesometapleural suture with a well marked little spot at the level of the spiracle and also on the end of this suture. The spiracle is less intensively dark edged. The black spot on the metapleural suture is limited only to the superior third of this suture, the inferior third is less intensively dark. The coxa of all legs are spotless. General thorax colour in mature specimens is brownish-ochre, sporadically with an orange or greenish-yellow tinge. Well-marked antehumeral stripes are on the front of the thorax edged with brown. Frons and clypeus light-ochre, in the centre orange-red. Abdomen ochre-reddish with dark brown colour on 1st stemite and on the first half of the dorsal side of the 2nd stemite. In immature specimens frons and thorax are light greenish-yellow, abdomen is light-ochre. Legs (Fig. 2) well marked with black on inner sides of femur and tibia, black-brown tarsus. The rest of the legs are ochre-yellow with a less expressive brown stripe on dorsal side of the femur. On 20th August 1996 at Klokocov near Zemplinska Sirava reservoir (eastern Slovakia, 110 m above sea level) I managed to catch both a male and female of this species in tandem. In the female the colour was typical, but the male was different mainly in the extent of the black spots on the thoracic sides (Fig. 3). The black spot on the superior part of the humeral suture elongates downward, thus the suture is margined lengthwise with a thin black line. The black spot on the inferior part of the mesepimeron protracts up to the mesometapleural suture. Similarly the black spot on the inferior side of the mesinfraepistemum protracts to the front and to the mesopleural suture as well. The spot on the inferior side of the metepisternum is more extensive. Mesometapleural suture is edged with a thin line, a similar line is also on the suture leading from the metapleural suture to the spiracle. Spiracle is dark edged. The spot on the inferior side of the metepimeron reaching the metepistemum is more extensive and protracts backward with 2 toothed projections. Metapleural suture is margined with a thin black line emanating from the black spot on the superior part of this suture. The coxa of all legs have black spots on the front sides. Frons, clypeus and labium in this male are orange-red with ochre on the side of the frons. Thorax is dark brown-ochre, with inconspicuous antehumeral stripes. Thorax sides sporadically with a red tinge, infraepisternum is yellowish, coxa reddish. Legs (Fig. 4) black on inner sides of femur and tibia; on the outer sides of the femur there is a broad black stripe, the brown-ochre colour on the femur is limited only to a narrow stripe; tarsus is brownish-black. Abdomen orange-red, 1st sternite and the first half of 2nd stemite dark brown.