THE WOOD-BORERS 



o'clock in the morning, and the two that were laid earlier 

 between two and three in the afternoon. This was the 

 biggest day's hunting that we have ever recorded for any 

 of our wasps. 



With both species (T. rubrocinctum and T. albopilo- 

 sum), when the preliminary work of clearing the nest 

 and erecting the inner partition has been performed by 

 the female, the male takes up his station inside the cell, 

 facing outward, his little head just filling the opening. 

 Here he stands on guard for the greater part of the time 

 until the nest is provisioned and sealed up, occasionally 

 varying the monotony of his task by a short flight. As 

 a usual thing all the work is performed by the female, 

 who applies herself to her duties with greater or with 

 less industry according to her individual character ; but 

 the male doubtless discharges an important office in 

 protecting the nest from parasites. We have frequently 

 seen him drive away the brilliant green Chrysis fly, 

 which is always waiting about for a chance to enter an 

 unguarded nest. On these occasions the defense is car- 

 ried on with great vigor, the fly being pursued for some 

 distance into the air. There are usually two or three 

 unmated males flying about in the neighborhood of the 

 nests, poking their heads into unused holes, and occa- 

 sionally trying to enter one that is occupied, but never, 

 181 



