312 THE ENTOMOLOGIST. 



River, will not have any difficulty in realizing how short a 

 period would be necessary to cause death." — From Capt. 

 Butle)-'s ' The Great Lone Land.' — Communicated by F. 

 Walker. 



A Plague of LarvcB. — I know not whether it has been the 

 case in other localities, but in this neighbourhood the abun- 

 dance of larvae of P. Brassicae is unprecedented. All the 

 cabbage tribe have been totally eaten up in some places, and 

 nothing but the veins and stalks remain. Not content with 

 that, the larvae have entirely stripped the turnips of their 

 leaves; and even the leaves of the horse-radish have been so 

 eaten that only the stalks are left. Many of the gardens 

 present a pitiable spectacle from the ravages of these 

 voracious caterpillars. 1 have been rather amused at some 

 of the remarks passed with regard to the abundance of these 

 creatures, for it must be understood that Entomological 

 knowledge is at rather a low ebb in this immediate neigh- 

 bourhood. One old woman asked me if I did not suppose 

 that these larvae were like the locusts of which we read in 

 Scripture, and were sent as a judgment for the sins of the 

 nation ? On another occasion a man, wishing to show his 

 knowledge of the theory of metamorphosis, was explaining to 

 his neighbour how quickly the larvce propagated, and that the 

 smaller ones were the offsprings of their larger brethren, and 

 he added : " During the winter they hide in holes, and under 

 the earth ifi cases; and next spring we shall be swarmed 

 more than ever. Mr. Corbiu says they come from butterflies; 

 but / can prove he's wrong." Having overheard the latter 

 conversation, I explained to my learned friend that a small 

 and — by him — unobserved creature, in the form of a four- 

 winged fly, was proving a great friend to him by destroying 

 these caterpillars; in fact, 1 told him of the busy ichneumon 

 fly and its work : but he received the facts with a shrug 

 of the shoulder, and the words — "I am older than you." I 

 have observed that as these larvae prepare to pupate, quite 

 two-thirds of them are "stung;" so I scarcely accept the 

 conclusion that next season we shall have a still greater 

 abundance. There did not appear to be an unusual number 

 of the imago of Brassicae in their season ; in fact, they were 

 not half so common as they were a few seasons ago, when 

 they literally swarmed everywhere j so that I attribute the 



