DIAMOND-BACK MOTH. 159 



the shores (and in various cases proved to be Diamond-backs by exa- 

 mination of specimens, or by the attack that followed their presence 

 being of Diamond-back caterpillar), that the infestation spread 

 inland. 



It has been objected to this view that it is quite possible that the 

 quantities of moths seen at Hartlepool, and at the Fame Islands, 

 " came from neighbouring localities inland, attracted by the lights of 

 the lighthouses." * It does not, however, appear to me that such 

 could be the case, because on writing to Mr. John E. Kobson, Fellow 

 of the Entomological Society, who had recorded the Hartlepool attack 

 with great care, he replied: — "Hartlepool lighthouse stands at the 

 end of a promontory, but shines no light to land within many miles. 

 Across the bay to the Cleveland Hills is the nearest, perhaps twelve 

 miles away." Also on applying further for information on this matter 

 to Mr. W. Belk, Engineer to the Port and Harbour Commissioners, 

 Hartlepool, he favoured me by writing as follows : — " Belatively to 

 moths, &c., appearing at this place on or about June the 24th, I am 

 of your opinion that it would have been almost impossible that the 

 lighthouse here could have caused the attraction, as the light is 

 obscured one-third to the landward, and bright two-thirds to the sea." 

 — W. B. 



Also it is to be observed with regard to direction of progress, that 

 Mr. Eobson, though collecting (entomologically) inland on the 24th of 

 June, noticed none of these moths at the locality Hezleden Dene, 

 about one and a half miles from the coast, and on returning to Hartle- 

 pool found them in vast numbers. They disappeared almost entirely 

 from Hartlepool in two or three days, and on the 26th were swarming 

 at the inland locality Hezleden Dene, where they were known to be 

 absent two days before. In regard to the Fames (that the cloud of 

 moths was driven by the N.E. wind), see line 2, p. 157 ; and we have 

 also notes of the inland progress. And again, looking at coincidences 

 further north it is of interest to note that the direction of the wind at 

 Leith at 8 a.m. on twenty of the thirty days of June (as given in the 

 daily weather report issued by the Meteorological Office), was E. ; 

 E.N.E., or N.E. ; which prevalence may have borne much on the 

 great amount of attack in Fifeshire, over which county and along which 

 seaboard the N.E. wind would especially sweep. 



The matter of the wherefrom of the pests is of so much importance 

 practically, that it seems worth while to go into it so far as is possible. 

 Amongst all the reports sent me there is no local evidence of the attack 

 being home-bred. If such had been the case, it might on all general 



* See Eeport of the Intelligence Department (Board of Agriculture) on '-Attack 

 of the Diamond-back Moth caterpillar in 1801," p. 20. 



