IOO 



THE BRITISH NATURALIST. 



[April 



them. During hard weather most of the insects pass deep into the 

 soil, and so escape the cold. Those that remain above are quite im- 

 pervious to its effects. The maggots of the turnip-gall Weevil, even 

 when extracted from their gall, can withstand 20° of frost (F.) and even 

 30 0 does not kill them, unless continued for some little time. In their 

 galled patches I find they can withstand even greater extremes, and 

 this only retarding their development a few days. I have often 

 noticed wireworms upon the ground alive when the thermometer has 

 been down to 17 0 of a night, and two cases I find in my notes where 

 wireworms were found amongst white turnips in 1886, the thermometer 

 registering 6° above Zero (F.) only. The majority of pests, however, 

 pass the winter in the egg and pupal stages (some also as adults). In 

 these stages the cold in England has no effect, except in retarding 

 development. It is not at all an uncommon thing to find the chrys- 

 alids of some of our Rhopalocera frozen quite hard, and brittle as 

 glass, and yet alive. As I have mentioned the Rhopalocera (butter- 

 flies) here, it is as well to point out, that they are not all injurious to 

 crops, as I have more than once heard and seen stated ! Four species 

 only can be claimed as injurious insects, and we must remember that we 

 have 72 recorded species. I should advise those who are interested in 

 horticulture and agriculture not to be misled by incompetent people 

 recommending them to carry out the wholesale destruction of such 

 (and other) insects. If they do they will soon discover they are doing 

 more harm than good. But more of this anon. To return to our 

 subject, frost not only does no good in killing such insects as are 

 obnoxious, but the hard state of the ground actually protects them. 

 They are driven deeper into the soil, and at the same time the hard j 

 ground protects them from the prying eyes and strong beaks of many 

 of our birds, which would otherwise destroy them in large numbers. — 

 Fred. V. Theobald, M.A., F.E.S. 



On Aciptilia Migadactyla, Haw. — (Spilodactyla, Curt.). — Mr. 

 Dale does not, apparently, appreciate the meaning of the passage in the 

 January number of the British Naturalist, page 8, which he criticises. 

 What has the dictionary meaning of the word " original" to do with j 

 my usage of the word in its relation to its context ? Naturalists have j 

 adopted a very wise rule, that the earliest name of a species given with 

 a description or figure of that species recognizable, shall be the name 

 of that species. Fabricius gave a short description of a white " plume " 

 moth, which he named migadactyla, and a few years afterwards!' 

 Haworth, describing only British species, believed he recognized in this; 

 description a British species. He therefore quotes the original descrip- 

 tion of Fabricius, applies it to the British species, but extends that, 

 description by references to its habitat, &c. Many years afterwards: 

 Haworth's species is described under another name {spilodactyla) by; 



