194- PROTECTION AGAINST INSECTS. 



Humble-bees {BoDihus tern-stris, L.) live in the ground in 

 societies of fift}' to sixty members. 



The hone}^ bee {Apis mclUjka, L.) is widely spread over the 

 earth. A hive may contain 1 ? , 600 to 800 3 , and 15,000 to 

 30,000 ^? . The 2 (queen) lives for five years, the 3 only for 

 a few weeks, and the '? for about six months. 



Order III. — Dipteua. 

 1. AsUhiar. 



Imagos long and generally slender, the face tufted with hairs. 

 Eyes very prominent, 3 ocelli, the suctorial organs forming a 

 pointed piercing tube. Antennae short, 3-jointed, the third 

 joint elongate, not annulate, terminated by a short bristle. 



Wings when at rest lying flat on the body. Legs stout, with 

 sharp curved claws. Abdomen with 8 segments. 



Larvae long and cylindrical, with very clearly marked 

 segments, white. 



The eggs are laid in the ground, by choice in sandy soil. The 

 generation is annual. The perfect insects are bold marauders, 

 they attack other insects of all orders and suck their juices. 



Species. — Aeilus cmhronij'ormis, L., common in Germany 

 and England. 



2. Siirphidae. 



tmagos with oval bodies, very large eyes, and 3 ocelli. An- 

 tennae 3-jointed, the last joint generally flattened, sometimes 

 very long, with a bristle-like appendage. Wings much inter- 

 sected with veins. Abdomen variable in form, with 5 to 6 

 evident segments. 



Larva leech-shaped, of varied colours. 



Piqja coarctate, pear-shaped. 



They fly in July and August in bright sunshine. Their 

 flight is of a hovering nature ; they remain poised over a 

 blossom, darting away when disturbed, and resume their hover- 

 ing at the end of their course, and they emit a buzzing noise. 



The small white oval eggs are laid on leaves and twigs. The 

 generation is double, or nuiltiple. The larvae, which inhabit 

 plants, destroy plant-lice by sucking out their juices. 



