28 



continued to appear until the last of September, and although I 

 watched carefull)^ for the appearance of callow workers, every adult 

 proved to be a male. These males did not seem to do well, as there 

 were never more than 15 or 20' males in the nest at the same time; 

 but there were certainly more than 100 that emerged. This agrees 

 with the general opinion that the offspring of unfertilized eggs of ants, 

 as well as of bees, are always male, although Mrs. Comstock 

 (Wheeler, '03) obtained normal workers from worker eggs. In a 

 small queenless colony of Formica schaufnssi that I watched, the 

 offspring from worker eggs were all males. This brings up the 

 interesting question as to whether the fertilized eggs of a fecundated 

 queen ever produce males. Certainly they do not the first year, and 

 most probably not the second. It is worthy of note that the same 

 conditions which will develop winged females in a colony, that is, 

 optimum conditions of food, temperature, and moisture, will also 

 cause the workers to lay eggs and thus bring about the production of 

 both the sexual forms. 



The probable life of a colony is but a year or two years longer 

 than that of the queen which founded it. After the queen dies the 

 eggs laid in the nest will all be worker eggs and produce males. In 

 strong colonies a few eggs would also be laid the second year, but the 

 next year the colony would perish, or perhaps serve as a host for some 

 species whose queen is temporarily parasitic upon I,, nigcr aincricanus, 

 as I have shown to be the case with Lasiits uiiibratiis var mimitiis 

 (Tanquary, '11). Or it may serve as the host of young dealated, 

 fertilized females of the same species, just descended from their nup- 

 tial flight, as I have shown that at times such queens may be adopted 

 by small queenless colonies of this species ('ii). The death of the 

 queen the year before must account for my finding large colonies of 

 this species which contained many hundreds of males but no females. 



SUMMARY 



1. Dates for which I have evidence of nuptial flights of Lasiiis 

 nigcr aincricanus are September 5, 9, 18, 20, 19 to 29, October 4, 11, 

 and 18. 



2. The flights generally occur in the afternoon between 3 o'clock 

 and 6 o'clock. 



3. The time of a flight is partly determined by weather conditions. 



4. Fertilization probably takes place in the nest. 



5. The young queens eat a large proportion of their eggs. 



