June, 1917J Winter Observations of Muscid Flies 289 



In the presence of artificial heat and breeding media Lucilia 

 scricata in addition to Musca domestica was collected in all 

 stages in the insectary all winter. On the 25th of February, 

 19 1(), two males and one female were placed in a breeding cage 

 (of the type previously described) over some banana and 

 fresh beef. This female deposited 4 masses of eggs before she 

 died — one on the 3rd of March, 1916, containing 163 eggs (by 

 actual count) another on the 6th of March, containing 232 eggs 

 (by actual count) another on the 9th of March, containing 

 119 eggs (by actual count) and another on the 14th of March, 

 containing 200 eggs by estimate. Thus in early spring a female 

 of unknown age produced 714 eggs within a period of 7 days. 

 A female emerging March 22nd from this first mass of eggs was 

 placed in a cage with 3 of her brothers under conditions similar 

 to that of their parent. On the 7th day after her emergence 

 this female produced her first batch of eggs. 



On the 15th of October, 1916, a fish head literally covered 

 with muscid eggs was taken from a garbage can at one of the 

 boarding-house stations and placed in a battery jar over an inch 

 layer of moist sand. In the insectary most of the eggs hatched 

 within 24 hours and shortly afterward, on the 17th of October, 

 the fish head became insufficient, therefore necessitating more 

 food. The maggots became so numerous within the jar, which 

 was covered with a glass plate, that they formed a horizontal 

 layer, standing on their heads, so that on looking down upon 

 the mass one could see a wave of wriggling, crowding, pushing 

 posterior ends. Still more fish was provided for them and when 

 this could not be obtained soon enough, they began feeding upon 

 one another. Many empty skins were found punctured with 

 holes made by the greedy survivors who then proceeded to 

 pump the body fluids from their companions. 



Just as soon as these maggots pupated they were placed 

 over moist sand in vials (1 inch in diameter by 3 inches tall) and 

 covered with a tight cotton plug. These vials were placed 

 in a rack about 10 inches from a south window (shaded from 

 southwest by the front of the building) of the laboratory 

 where the room temperature averaged 70° all winter. Most 

 of the maggots pupated 15 days after hatching. Others appear- 

 ing to be in a pre-pupal stage were placed in vials November 

 1st. Of this latter lot, some pupated in 64 days, others 81 days 

 and still some in 101 days after hatching. The pupal period 



