234 WASP STUDIES AFIELD 



we watched her. She carried large loads, and the soil was 

 sandy and crumbled readily; so she bore each load with 

 both front legs around it. Some species of wasps reserve 

 near at hand just enough dirt to fill up the channels of their 

 burrows when they close them, and throw away all that 

 comes from the deeper chamber. It is possible that this indi- 

 vidual showed a reversion to this type, or was a sport just 

 developing it, but we fancy that it is more probable that she 

 was merely a freak, since when we dug up the hole we 

 found the horizontal chamber much larger than usual. The 

 caterpillar, one of only medium size, seemed quite lost in it. 

 It might be that the pile near the orifice had been accidentally 

 dropped when she emerged from so great a depth. It may 

 seem to some that we give an undue amount of attention to 

 petty details of this order, but we want to record every point 

 and search every detail which might lead or contribute to 

 knowledge of the origin of new habits. 



The duration of the period of development of the larva of 

 Ammophila, or the time from the deposition of the egg until 

 the pupation of the larva, is brief but somewhat variable. 

 One usually finds the egg hatched on the second day, unless 

 it has been deposited late in the day, in which event the little 

 larva, about five mm. in length, is not present until two days 

 after oviposition. By the fifth day of its existence, the 

 larva usually becomes large, fat and white, and the next day, 

 or at most two days thereafter, it spins its white, silky co- 

 coon. During the growing stages, the larva seems only to 

 suck the juices of its host; but, if it is hungry on the last day 

 of its gormandizing, it sometimes devours even the tough, 

 withered carcass of the caterpillar. When it has attained 

 its full growth and is ready to spin, it announces the fact 

 by a peculiar way of writhing to and fro. We have not yet 

 ascertained the real reason for these contortions. How- 

 ever, it is interesting to note that Ammophila always pupates 



