210 On the Insects affecting the Turnip Crop. 



perhaps be advantageously employed in driving away or deceiving 

 the fly. One ounce of tar, one ounce of olive oil, and two ounces 

 of strong caustic potash, well mixed together, and shaken up with 

 the requisite quantity of water, were next poured, the fourth day 

 after sowing, over a patch on a hill swarming with the fly^ at the 

 end of August. Not many of the seeds came up, but the few 

 plants from them were of a healthy colour^ and acquired the rough 

 leaf; a few only on the windward side being punctured; but 

 several days' rain occurred at the most critical time, which might 

 be their best protection. 



Such are the remedies proposed ; but I fear it is not by the 

 experiments of a few philosophic men that we can hope to discover 

 any positive antidote to so great an evil. We want correct data 

 from every sort of soil under the various influences of climate and 

 effects of cultivation, before we can fairly grasp the subject. Until 

 we became acquainted with the economy of the beetle we were 

 groping in the dark. That important discovery has brought us a 

 few steps towards the light; and those who v/ish to follow in the 

 path of truth should try and examine Mr. Le Keux's experi- 

 ments, which it is easy to do, by filling a garden-pot with earth, 

 carefully sifted to take out all worms, centipedes, or other living 

 animals, which might destroy the chrysalides. When this is done, 

 plant in it a small turnip, in rough leaf, having a fine wire-gauze 

 guard, large enough to enclose the plant, and fitting just inside 

 the top of the pot. One or more pairs of the beetles must be 

 placed, with a fresh turnip leaf, in a large-mouthed transparent 

 bottle, then tie over the end a piece of muslin, to prevent the 

 escape of the insects ; for if the cork or stopper be put in, the 

 bottle will become wet inside, which will prevent the females from 

 laying any eggs. I imagine they will not adhere to the damp leaf. 

 The leaf may be examined daily through a magnifying-glass, and 

 as soon as any eggs are discovered they may be placed in the pot 

 where the turnip is growing, that the little maggots may be able 

 to get at the living leaves as soon as they hatch. The progress of 

 the insect may thus be traced through its different stages ; and it 

 will only be necessary to place the garden-pot in a saucer, into 

 which water should be daily poured, if necessary, to nourish and 

 refresh the plant. 



Let us not forget that amongst our best friends are the small 

 birds, a great number of which, such as the grey and yellow wag- 

 tails, no doubt destroy incredible numbers of these insects in their 

 various stages. Their nests ought to be protected, and the birds 

 themselves defended from persecution. 



There is another species of Altica, whose habits are similar to 

 those of Altica nemorum, which materially assists in injuring the 

 turnip-crops. The habits of the brassy or tooth-legged turnip- 



