1922] Taylor — Biology of Wasps of Genus Ancistrocerus 63 



2. The nests made by these wasps in glass tubes have the 

 following characteristics : 



a. Tubes having diameters of from six to eight millimeters 

 were utilized by the wasps. 



b. Nests consist of from one to four cells, these apparently 

 varying in length conversely to the diameter of the tube, the 

 inner cells being usually larger than the outer. The cells are 

 separated by partitions of mud which the wasp makes by mixing 

 fine sand and water. 



c. The cells are each provided with an egg, suspended by 

 a filament from above and each contains from three to fourteen 

 caterpillars; these are supplied after the egg has been deposited. 



3. The caterpillars are paralyzed by the wasp by stinging 

 probably at some point near the thorax. 



4. From rather fragmentary evidence it appears that the 

 larger, inner cells contain eggs which are destined to produce 

 females, while the smaller, outer cells contain those which are to 

 become males. 



5. There are probably two generations of these wasps 

 -annually, the eggs of the first being laid from mid to late June, 

 the adults from them appearing during the first half of July. The 

 eggs of the second generation are laid during the latter part of 

 July and the first of August, the wasps from them hibernating as 

 larvse and probably emerging in June. 



6. From the longevity of certain of these wasps in captivity 

 it is concluded that the females live long enough to construct 

 several nests of the sort described here. 



7. The females are apparently guided to their nests by 

 certain landmarks, but are not helpless when such landmarks are 

 removed or distrubed. 



8. Dipterous larvse, Chrysididae and perhaps ants have 

 been observed as enemies of the species studied. 



