384 The Diamond-hack Moth. By George Bolam. 



laro^e proportion prodnced ichneumons, which I found to agree very closely 

 with Curtis' description of C. paniscus, — no variation, except perhaps a 

 little in size, being noticed among them, although the larvae from which 

 they came were gathered from a variety of wild and cultivated plants. I 

 must, however, disclaim any particular knowledge of this branch of 

 Entomology : and it is quite likely that the slight differences which go to 

 distinguish one species from another, may in some cases have been over- 

 looked. In connection with the abuudauce of Ichneumons last year, an 

 interesting question arises for solution by the believers in the theory of 

 migration. Supposing the moths really did come to us from abroad, how 

 is the great increase of the parasites in their larvae to be explained ? Did 

 their progenitors follow the moths across the seas, or were they already 

 upon our shores in numbers sufficient to cope with the myriads of the 

 invaders ? 



Birds also render much service in preying upon the moths, as well as 

 upon their larvae. Of the enemies of the perfect insect, perhaps the most 

 important are the Martins and Swallows, which, hawking low over the 

 fields, must devour immense numbers of them. Amongst those which are 

 supposed to be most destructive to the caterpillars, Starlings held the 

 foremost place in the opinion of Miss Ormerod's correspondents, being 

 mentioned in twelve out of twenty-two communications. Sparrows came 

 next, though with such qualifying remarks as they '' preferred the barley," 

 or were " too much occupied with early oats to have time to spare for 

 caterpillars"; and amongst other birds mentioned were Rooks, Larks, 

 Plovers, and Sea Gulls, with several small birds, as Linnets, and Yellow 

 Hammers and by one gentleman "fowls of all sorts" were said to have 

 "followed the hoers and eagerly eaten the caterpillars." Personally I am 

 no believer in Sparrows, and am rather inclined to think that the larvae of 

 P. cruciferarum are too small to attract much attention from some of the 

 larger birds, but Plovers, and Sea Gulls, will at any rate do no harm 

 amongst the turnips, and where the caterpillars are very numerous will no 

 doubt eat a lot of them. Partridges might also claim to be added to this 

 class, but I think that most good is done by the smaller, soft-billed, birds. 

 White-throats in particular, which are always fond of frequenting a turnip 

 field, probably find little other food amongst the broad leaves, and upon one 

 occasion I watched them, busily engaged in picking off the larvae, while 

 near the sea-banks. Pipits and Wheacears were also present under suspicious 

 circumstances. Starlings I look upon as among the best all round feathered 

 friends of the agriculturist. 



The only accurate way of obtaining information upon this point however, 

 is by an examination of the stomachs of birds killed upon the spot, and 

 owing to ' close times' and other causes, there is a difficulty in obtaining 

 specimens, and few birds have had this close, albeit, to them undesirable, 

 attention paid to them. In three or four Larks examined. I could find no 

 trace of caterpillars amongst their recent food, but in a Yellow Hammer 

 one or two larvae of the Diamond-back were present. A Peewit also was 

 found to have been eating some of them ; but with these my own 



