June, 1917] Winter Observations of Muscid Flies 291 



Maggots of L. caesar were again taken from guinea-pig 

 manure on January G, 1917, producing adults from 20 to 32 

 days later. From this it is suggested that L. caesar may 

 spend the winter in the larval stage. 



Lucilia sylvarum Meig. 



This species seems to occur still less frequently than the 

 others. A maggot of this form, however, was taken from the 

 guinea-pig manure pile containing carcasses on the 27th of 

 October and was placed in a vial in the laboratory where it 

 pupated 88 days later. The male emerged 33 days after this, 

 thereby requiring a developmental period of more than 121 days. 



Phormia regina Meig. 



The king of blow^fiies was taken on the 12th of November, 

 191G, near a garbage can at one of the stations and was not 

 collected again until the 24th of March, 1917, when it was 

 trapped with meat bait. 



Among the masses of eggs taken October loth, 1915, on 

 the fish head described with Lucilia sericata there were also eggs 

 of Phormia regina. Pre-pupal maggots were transferred from 

 the battery jar in which they were fed, to the breeding vials 

 in the laboratory where they pupated in 15 to 45 days after 

 hatching. The pupal period was brief, extending from 2 to 7 

 days, adults issuing from November 7th, 1916 (23 days from 

 egg) to December 8, 1916 (54 days from egg). Some of these 

 fresh adults were placed over banana and fish in a breeding 

 cage in the insectary. No eggs were produced. Four males 

 and three females emerged and were immediateh^ transferred 

 to the cages on the 5th of December. In four days 1 male and 

 1 female were found dead, in five days another pair and still 

 another pair in six days. The remaining male died in eleven 

 days, or December 16, 1916. 



A similar longevity test was made with 3 males and 6 females 

 emerging on the 7th of December. One female died in 2 days, 

 another in 3 days, a pair in 4 days, 1 male and 3 females in 5 

 days and the remaining male on the 10th day. 



A peculiar phenom.ena in the manner of emergence was 

 observed at this time. Similar conditions, however, were 

 observed when working with puparia of Musca domestica, 

 Lucilia sericata and Sarcophaga sarracenia^. Apparently an 



