The Glow-Worm and Other Beetles 



fectually upon an insect, I should advise as- 

 paragus-growers to have recourse to the 

 Tachina, though I should cherish no illusions 

 touching the results of the expedient. The 

 exclusive tastes of the insect auxiliary draw 

 us into a vicious circle : the remedy allays the 

 evil, but the evil is inseparable from the re- 

 medy. To rid ourselves of the ravages of the 

 asparagus-beds, we should need a great many 

 Tachinae; and to obtain a great many Ta- 

 chinae we should first of all need a great many 

 ravagers. Nature's equilibrium balances 

 things as a whole. Whenever Crioceres 

 abound, the Midges that reduce them arrive 

 in numbers; when Crioceres become rare, the 

 Midges decrease, but are always ready to 

 return in masses and repress a surplus of the 

 others during a return of prosperity. 



Under its thick mantle of ordure the grub 

 of the Lily-beetle escapes the troubles so fa- 

 tal to its cousin of the asparagus. Strip it 

 of its overcoat: you will never find the ter- 

 rible white specks upon its skin. The me- 

 thod of preservation is most effective. 



Would it not be possible to find a defensive 

 system of equal value without resorting to 

 detestable filth? Yes, of course: the insect 



need only house itself under a covering 



424 



