— 215 — 



doubt, the naturai conditions for its complete and rapid establish- 

 ment in N. Z.; I am supported in mj'- wiews by the unplea- 

 santly numerous cases of typhoid, dysentery, diarrhoea, and 

 of course, the inevitable « Grippe »; the presence of these 

 diseases betokens also the presence of the naturai conditions 

 requisite for E. tenax, viz.: stagnant pools, ponds, drains 

 and sewers etc, caused by the abnormally dry season, while 

 the creeks and rivers have not been so low for twenty-seven 

 years... » 



« I have endeavoured to show what appears to me to have 

 been the chief cause of the irruption of E. tenax in N. Z. 1890; 

 it however leaves unexplained how and when the species was 

 introduced; but in the absence of positive proof, I think it 

 probable that it came to N. Z. from the Pacific coast, the 

 numerous intervening groups of islands would provide a ready 

 means of dispersion, if the necessary condition for its larvai 

 stage existed in the islands; nevertheless, I think that in ali 

 probability it was imported direct by the mail-steamers which 

 have plied monthly between S. Francisco and Aucldand for 

 the last twenty years; from this source unquestionably came 

 Carpocapsa pomonella (1) in imported apples to N. Z. ; possibly 

 we may soon have records of the occurrence of E. tenax in 

 other islands of the Pacific. » 



A short notice, published by the sanie author two years 

 later in the Entom. M. Mag. London, 1892, p. 110, may 

 likewise be reproduced here : 



« This fine mimicking Dipteron is not quite so numerous 

 in this district tliis season as it was at this time last year. 

 I think it may in some measure be due to the greater rainfall 

 of last wiuter, in flushiug the stagnant and swampy pools 

 where the larvae chiefly exist. I was lately at a woolscouring 

 Works half a mile from Ashburton, and observed the larvae in 



(1) A two-winged insect ofthe family Trypetidae, which iufests apple-plantations. 



