228 



Mil. A. 31. ALTSON ON THE LIFE-HISTORY AND 



grounds." In lot No. 5 they bred 228 males and 116 females 

 from " host puparia in fsecal matter, miscellaneous." These lots 

 represent the most complete figures for material parasitized 

 under natural conditions, and clearly indicate parthenogenetic 

 reproduction. 



Length of Life of Adult. — As previously stated, females kept 

 amply supplied with liost puparia and a little food lived from 

 3-4 weeks. The males confined with these females only live 

 7 or 8 days. 



In Australia, under similar conditions and in the cooler 

 weather, they are stated to live from 4 to 6 weeks (7). 



When confined in glass cylinders without food or host puparia, 

 they were found to live from 4 to 6 days, the males dying 

 first (6 and 7), and when confined in glass cylinders with food and 

 no host puparia, they were found to live from 18 to 20 days (7). 



" The difterence in the length of the life of the wasps kept in a 

 confined space, and of those actively at work in the cages, may be 

 due partly to the direct effects of confinement; but in the writer's 

 opinion, it is due more to over-copulation of the females in the 

 confined spaces '* (7) This may be partly accountable, but the 

 females appear to be quite capable of resisting the advances of 

 the males, and the ^vriter suggests that the undetermined drop 

 of liquid which sometimes exudes from the punctured puparium, 

 and which all observers agree is generally "sucked up" by the 

 female, may contain nutriment. This would explain why those 

 confined with food and host puparia to deposit eggs in, live longer 

 than those with food and no opportunity to deposit eggs. This 

 view is further supported by the fact that (under breeding 

 conditions) the females seldom left the dishes containing host 

 puparia for food. 



It has, however, been ascertained that individuals of both 

 sexes can live for some time with very little food. In the case 

 of three females (presumed to have mated) each was confined 

 separately in tubes within 14 hours of emergence ; and into each 

 tube a minute drop of food was placed on the glass by the aid of 

 a needle ; no further supply was given. The first female was 

 (lead on 15th day, the second on 19th day, the third on the 21st day. 

 Of three males confined separately in tubes (none of them had 

 had an opportunity to mate) and given a similar initial drop of 

 food, one managed to escape on the 7th day through a fissure 

 in the cork, another died on 14th day, and the last on 22nd day. 

 No test was made with virgin females. 



Food. — In the laboratory the same food as was used for the 

 braconids and flies was given to these, but very infrequently and 

 only a very little at a time, otherwise they would get stuck in it ; 

 and if their wings came in contact with it, they seemed quite 

 incapable of extiicating themselves. How the semi-apterous 

 males obtain food under natural conditions is not known ; and 

 taking into consideration their habit of remaining in the imme- 

 diate vicinity whence they emerge, it is very probable that mos^ 



