94 INJURIOUS AND USEFUL INSECTS 



first ; two or three young queens may now be allowed to 

 accompany the other bees. As the brood-cells continue to 

 yield new bees, a third, fourth, and even a fifth swarm may 

 be sent off within a day or two of the second. When about 

 three weeks have passed since the departure of the old queen, 

 the eggs laid by her will probably be exhausted, and as the 

 new queen will hardly have begun to lay, the hive may be 

 for a time almost unprovided with brood. When swarming 

 is over, the eldest of the remaining queens is allowed to leave 

 her cell and destroy the others. It is only the first swarm 

 which possesses a fertile queen. The later "casts," as they 

 are called, have only virgin queens, and are not ready to 

 rear brood until she has sought the drone. She has to leave 

 the hive for this purpose, and runs risk of being lost or 

 destroyed. If this should happen, the swarm is ruined, and 

 will slowly dwindle away. A virgin queen is less valued than 

 a fertile queen, and receives much less attention from the 

 workers. 



Since all the bees of a hive are usually the progeny of 

 a single queen, they may be considered as one family, 

 numbering as many, perhaps, as 40,000, or even more. 

 Occasionally a new strain of blood is introduced by means 

 of a drone from another hive, or by the introduction of 

 a new queen. The queen can only be introduced with great 

 precautions. She is brought in by means of a perforated 

 box, and allowed to acquire what is called the smell of the 

 swarm, before the bees are allowed access to her. 



20. THE GOOSEBERRY SAW-FLY {Netnatus ribesii) 



The eggs are laid along the veins of g'ooseberry or currant 

 leaves. They seem to absorb moisture from the leaf, for 

 if a leaf is cut off and allowed to dry, the embryos in the 

 egg perish. About six days after egg-laying the larvse appear, 

 and begin to creep upon the leaf; they are at first 2 mm. 

 long. Very young larvae bite circular holes in the leaf; 

 but before long they eat along the edges, leaving nothing 

 but the midrib and large veins. The feeding larva is active 

 for about four weeks, and moults four times. It then enters 

 the earth and becomes a resting larva. A full-fed larva is 



