III. 



The Recent Plague of Wasps. 



r PHE remarkable summer just past has been signalised by such a 

 -»- profusion of what is perhaps the most generally unpopular 

 insect pest, that a brief revieAv of the facts may be of interest. Of 

 the seven British species of Vespa, no fewer than five appear to have 

 been more than usually abundant. So early as the beginning of 

 June both personal observation and reports from reliable witnesses 

 showed V. sylvestris and V. novegica to be well established and in 

 possession of strong nests. During the earlier portion of the summer 

 these two tree-wasps were, in S.W. Surrey, far more abundant than 

 the ground-wasps, V. vulgaris and V . gerinanica, which, however, were 

 in full force by the middle of July, while V. rufa was found more 

 commonly than in previous years, though it could not be said to 

 be numerous, at least from my own information. It is much to be 

 regretted that the letters and complaints in the daily newspapers contain 

 no hint as to the species of wasps abounding in various parts of the 

 country, though the context would in most cases point to ground- 

 wasps. Nevertheless, Mr. Lowe (Nature, vol. 48, p. 437) speaks of 

 "the tree-wasp " having had man)' nests in Monmouthshire, so that 

 we may reasonably conclude that the season has been favourable to 

 tree- and ground-wasps alike throughout England. Of the somewhat 

 mysterious V. arborea I have heard nothing, excepting the capture of 

 two females in Ireland (Entom. Monthly Mag., July, 1893, p. 166). 

 It is very singular the hornet, V. crabro, has hardly been reported 

 abundant anywhere. I cannot help thinking that this species is 

 decidedly on the wane and disappearing from our islands. Popular 

 observation on the point is well-nigh worthless, for many so called 

 " hornets " prove on inspection to be large female wasps. It would 

 be of great interest to ascertain from all counties whether the " red 

 hornet" has or has not become appreciably scarcer during the last 

 fifteen or twenty years. 



Turning now to the causes of this "plague," I have no hesitation 

 in ascribing it almost entirely to a remarkable series of meteorological 

 conditions advantageous to wasp life. Speaking of observations 

 made by myself, which in the main agree with those taken elsewhere, 

 it is noticeable that after March 23 there was no frost registered by 

 the screened thermometer, excepting slight ones on the nights of 

 April 13, 14, 15. Again, with regard to rainfall, from March 1 to 

 June 30 the total amount registered was only 2-38 inches on 27 days, 



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