i 4 4 



THE YOUNG NATURALIST. 



[■July 



Of the genus Deilephila probably all of them are visitants here. 

 D. euphorbia was formerly established at Braimton Burrows, near 

 Bideford, in Devonshire,* but it has long since disappeared from that 

 locality, and is now rarely reported as a visitor. D. lineata is perhaps 

 less rare, still it has no settled colony in England. 



D. galii is doubtless the most frequent of the three, but still I am 

 pretty certain that it fails to perpetuate its race in England, rarely 

 appearing more than probably one or at most two consecutive years. 

 Evidently our climate does not suit it. It is not warm or sunny enough 

 for its healthy development as I have shown, Y.N., p.p. 113 and 115 ; 

 one season here produces a much smaller and doubtless weaker insect. 

 Mr. C. A. Briggs admits that caught English specimens are larger 

 than bred examples from English larvae. But Mr. Briggs seems to 

 ignore that if these caught English imagines are produced by English- 

 fed larvae, that some of us, out of the great number that have been 

 bred from English-fed larvae, should be able to match the caught 

 examples, for it is simply absurd to say that all our bred ones must be 

 starved by our feeding ! Very many of my larvae were full-fed and had 

 changed colour for pupating when found, and I would ask Mr. Briggs 

 why these should not be as large as the caught examples ? The 

 reason to my mind is not hard to see. It is the cold and wet autumn 

 weather we get, and principally the want of bright sunshine, that 

 weakens our English-fed larvae and kills a very large percentage of 

 them. This was proved by my own experience. After the first few 

 wet and cold days we got in September last, I found the larvae 

 then moribund, and many dead ; see also report of Mr. J. Arkle 

 (Entomologist, Vol. XXI., page 257). Perhaps Mr. Briggs does not 

 fully realize what an average three-eighths of an inch mean. Let him 

 place, say the largest male specimen out of all he can get from Eng- 

 lish-fed larvae, viz., 2 inches 10 lines (and only one of that size), and 

 place it beside the males caught by Mr. J. T. Williams, at St. Mar- 

 garet's, Kent ; his males measured 3^ inches and over that, they do not 

 look like the same insect. My largest bred English female, 3A ins., 

 looks small indeed beside my French specimens of 3f ins. Mr. Briggs 

 is good enough to say that my previous remarks " are not even ripe 

 for discussion," because I had failed to give detail of the size of 

 Galii bred on the Continent ; but I have no hesitation in telling Mr. 

 Briggs that they would in no way affect the question. I do not sup- 

 pose that bred Galii have been carted over here, but that continental 



■* Is there any evidence that the larvae were found at Braunton Burrows more 

 than once ? If not, I would hardly consider the species established. — J.E.R. 



