THE ENTOMOLOGIST 



Vol. XLV.] MAY, 1912. [No. 588 



BKITISH ODONATA IN 1911. 

 By W. J. Lucas, B.A., F.E.S. 



So abnormal a summer as that of 1911 could not fail to pro- 

 vide points of interest to those who concern themselves with 

 British dragonflies. It may be that 1912 and 1913 will witness 

 a scarcity of some species, owing to the drying up of their 

 breeding-grounds, although it is quite possible that the race has 

 already provided against such a contingency. It is to be hoped 

 that observation in connection with this subject will be made by 

 those who work amongst the Odonata, or those who, though not 

 specially interested in these insects, are favourably situated for 

 making such observations. It seems likely that one immediate 

 result of the dry hot season was the migratory impulse that 

 appeared to be at work amongst the dragonflies, which will be 

 referred to later. 



Personally, the first date on which a dragonfly came under 

 my notice was May 7th, when one or two Agrionids were seen 

 near Oxshott, Surrey. They were not captured, but no doubt 

 were examples of Pyrrhosoma npnphula. On May 26th Mr. 

 B. S. Williams sent me four specimens, two males and two 

 females, of Libellula depressa (the males being without a trace of 

 blue colouring), which he had captured at Finchley, where he 

 had never seen the species before. Mr. H. W. Andrews showed 

 me L. quadrimacidata and P. nymphula, taken during a visit to 

 Glengarriff, co. Cork, from May 21st-26th. On May 28th Mr. 

 N. Fenwick, Jun., found large numbers of Cordulia cenea out at 

 the Black Pond, in Surrey. He took one male and three females, 

 and could have caught many more. L. quadrimaculata was out 

 in force, as also were P. nymphula and Enallagma cyathigerum, 

 but he saw no other species. On June 4th dragonflies were very 

 numerous at this pond, and, in addition to those already men- 

 tioned, a summer species, Pyrrhosoma tenellum, was on the 

 wing. A nymph-skin (species undetermined) was on this 

 occasion taken from the trunk of a Scotch fir some ten or twelve 

 yards from the pond and more than six feet above the ground. 

 The next day dragonflies were found to be plentiful at a small 



ENTOM. — MAY, 1912. M 



