1893.] HESSIAN FLY AND WHEAT MIDGE 239 



One special insect trouble during the past season in this 

 country has been an unusual prevalence of wasps, Vespidce, 

 of various species. They caused much injury and loss by 

 destroying fruit, and also were very troublesome by attack- 

 ing horses ploughing, if their nests were turned up. I hear 

 that they were also troublesome in Holland, and in the 

 Hartz districts of Germany. Should you write to me, I 

 should be very much interested to know whether they were 

 also unusually plentiful in Norway. 



i, 6, infested floret ; 2, 3, larvae ; 4, 5, cased larva or pupa, natural 

 size and magnified ; 7, 8, part of horns, magnified ; 9, 10, wheat midge ; 

 and 11-14, ichneumon parasites, natural size and magnified. 



FIG. 62. WHEAT MIDGE, CECIDOMYIA TRITICI. 



November 7, 1893. 



I beg to offer you my best thanks for your very acceptable 

 letter of the 3ist of October. Indeed, I am greatly obliged to 

 you for not only kindly giving me your own information 

 as to amount of wasp presence observed in the past season, 

 but also the translation into English of the account of their 

 great appearance at Tromso in 1883-4. This is exceedingly 

 interesting, and also very entertaining. I have enjoyed 

 reading this spirited account uncommonly, and I shall like 

 very much to add it (of course duly acknowledged) to my 

 paper on wasps in my next Annual Report. 



[The translation appeared as follows : 



" In the years 1883-1884, there was an unusual prevalence 



