THE PHORA PARASITE. 41 



The maggot moults three times. In twelve hours after the 

 last moult it turns around with its head towards the posterior 

 end of the body of its host, and in another twelve hours, having 

 become full-fed, it bores through the skin of the young, eats its 

 way through the brood-covering of the cell and falls to the bot- 

 tom of the hive, where it changes to a pupa in the dust and dirt, 

 or else creeps out of the door and transforms in the earth. 

 Twelve days after, the fly appears. 



The young bee, emaciated and enfeebled by the attacks of its 

 ravenous parasite, dies, and its decaying body lills the bottom 

 of the cell with a slimy, foul-smelling mass, called "foul-brood." 

 This gives rise to a miasma which poisons the neighboring 

 brood, until the contagion (for the disease is analogous to 

 typhus, jail or ship-fever) spreads through the whole hive, unless 

 promptly checked by removing the cause and thoroughly cleans- 

 ing the hive. 



Foul-brood sometimes attacks our American hives, and, though 

 the cause may not be known, yet from the hints given above we 

 hope to have the history of our species of Phora cleared up, 

 should our disease be found to be sometimes due to the attacks 

 of »uch a parasitic fly. 



We figure the Bee louse of Europe (Fig. 33 b, Braula csdca), 

 which is a singular wingless spider-like fly, allied to the wing- 

 less Sheep tick (Melophagus), the wingless Bat tick (Nycteribia) 



33. Bee Louse and Larva. 



• 



and the winged Horse fly (Hippobosca). The head is very large, 

 without eyes or ocelli (simple eyes), while the ovate hind-body 

 consists of five segments, and is covered with stifl" hairs. It is 

 one-half to two- thirds of a line long. This spider fly is "pupi- 

 parous," that is, the young, of which only a very few are pro- 



