Ixxvi JOURNAL OF I'ROC EEOtXGS. 



the threads outside, and only once or twice did he detect them in- 

 truding. This custom was not known there, but several of the in- 

 habitants who saw it immediately adopted it. 



" Monograph upon the Laraellicorn genus Diphucephala of Mac- 

 Leay." By G. R. Waterhouse, Esq. (See p. 215.) 



" Notice of the Ravages of a Black Caterpillar upon the Turnips 

 in the South of England." By W. W. Saunders, Esq., F.L.S., &c. 



After noticing the occasional appearance of various insects in vast 

 numbers, and the devastation which they produce, the author states, 

 that in no instance had he ever witnessed so great a destruction as 

 was exhibited in the turnip-fields in the neighbourhood of Dover 

 during last August, caused by a small blackish green caterpillar 

 which fed upon the leaves. 



These ravages were not confined to particular spots, but were seen 

 in places far apart, very few fields having escaped, although in some 

 the damage was less than in others, where the whole crop appeared 

 to be destroyed, twenty or thirty caterpillars being found on a single 

 plant, scarcely a vestige of green remaining ; the caterpillars then 

 seeking subsistence on the harder parts of the leaves, as the tendril 

 and nerves, which they at first refused. No attempt appeared to 

 have been made to remedy the evil. In a field at the back of the 

 Castle, which was half planted with Swedish turnips, and the other 

 half with the common kind, the former were untouched, but the 

 latter greatly injured, although only separated by a furrow, the plants 

 touching each other. Lime-dust or powdered chalk had been spread 

 over the attacked half of the field, and apparently with beneficial 

 results, but few caterpillars remaining. 



The botanical distinctions between the Swedes {Brassica campes- 

 tris, var.) and the common turnip {Brassica Rapa) were then detailed, 

 and it was observed, that the fact of their not touching the former 

 shows the nice distinction which larvae sometimes make in their 

 food, and which must be of considerable importance in an agricultural 

 point of view. The caterpillars were rather more than half an inch 

 long, and about as thick as a small crow-quill ; they were of a black- 

 ish green, with a pale lateral stripe, and pale underneath. The re- 

 markable dryness of the preceding summer was also noticed as worthy 

 of consideration, in connexion with the extraordinary apparition of 

 these insects, and as being probably very favourable to their growth. 

 Extract of a Letter from W. Mills, Esq., to the President, rela- 

 tive to the habits of the Corn Weevil. (See p. 241.) 



" Descriptions of several new Exotic Hemipterous Insects." By 

 J. O. Westwood. 



Respecting Mr. W. B. Spence's communication, Mr. Westwood 



