28 ANNALS OF SCOTTISH NATURAL HISTORY 



What caused it to change ground it is difficult to say. It 

 may have been due to one or other (or all) of three causes : 



(i) The intrusion of sEschna juncea into its feeding- 

 grounds. One littl-e glade, which must have been connected 

 by a favourable route with a good breeding-place for dragon- 

 flies, and in which I have seen three individuals of cccrulea 

 hovering round a big moss-covered stone facing the sun, was 

 one day suddenly invaded by half a score of the larger 

 species. (2) The warmer weather may have caused it, as 

 an alpine or boreal insect, to seek the cooler heights ; or 

 (3), most probable of all, when fully adult, it sought to be 

 near its breeding-places. 



In Rannoch this insect is usually found in the opener parts 

 of the woods. In Glen Lochay there is not the same extent 

 of woodland, and it seeks the shelter of the hollows down 

 which the little burns run, where there are usually thickets 

 or clumps of birches. In the latter district it has been ob- 

 served to be especially fond of basking on light-coloured 

 stones or moss, and it is indisputable that light-coloured 

 clothing, white nets, and such things, in strong sunlight, are 

 irresistibly attractive to this species, although its congener 

 s. juncea is rarely lured by anything of the kind. AL. ccerulea 

 is perhaps most susceptible to such attractions before fully 

 adult ; later it becomes shy, and always, if any attempt is 

 made to chase, it is difficult to capture, although its flight is 

 more jerky and less powerful than that of juncea. I have never 

 seen it carrying on the long-sustained hawking operations 

 which the latter insect delights in. 



I have indicated that in Glen Lochay AL. ccerulea is 

 usually found near burns. But I do not think the species 

 breeds therein. At present I am a little uncertain whether 

 it breeds in the lochans amongst the hills or in the less 

 constant waters of the peat-bogs ; more probably the former. 

 Still, it was about the peat-bogs the last examples of the 

 season were flying when taken some old males, rather ragged 

 in the wings, but with the blue colour of their bodies almost 

 dazzling in its beauty. It is the preponderance of blue that 

 serves at a glance to distinguish our insect from juncea. 

 Old males of juncea have the blue markings sometimes very 

 fine, but they are not nearly so extensive as in cccrulea. 



