March, '03] entomological NEWS. 77 



observations will have to be made to determine the exact way 

 in which the wingless female accomplishes such a difficult 

 task, yet the fact remains that the task was accomplished since 

 a pupating Mutillid was found in a sealed mud-dauber's nest. 

 An attempt to solve this enigma met with no success during 

 the past summer owing to an unusual scarcity of mud cham- 

 bers. The moist plastic clay used as building material by the 

 Pelopaeus was very scarce on account of a protracted drought 

 and this appeared to affect the habits of the host in a manner 

 so interesting as to be worth mentioning. The few^ nests 

 found never contained more than two chambers, and the 

 majority of these were deserted, unfilled and unsealed. Of 

 those that were sealed very few were well filled with the vari- 

 ous species of spiders which are taken under ordinary circum- 

 stances. At first I could not account for this destitute condi- 

 tion of the mud houses since it seemed a most propitious year 

 for spiders, they being in evidence on all sides. The only 

 explanation that occurred to me was that a relatively definite 

 amount of muscular energy was consumed by the mud-dauber 

 under favorable conditions in carrying out her house-building 

 and storing instincts. With unfavorable conditions this defi- 

 nite amount of energy was consumed in the displaying of the 

 instinct which came first, that of nest building. It does not 

 seem to be necessary to consider the question of intelligence 

 since the mud-daubers through change of environment were 

 offered every opportunity for adaptation. Whatever may be 

 the true explanation, the fact remains that in October on my 

 return to Austin, I was unable to find a single mud-dauber's 

 nest in places where they had always been found in such 

 abundance as to be considered nuisances. The ceilings of 

 verandas and the walls, furniture and books in rooms unused 

 throughout the summer which had been selected heretofore by 

 Pelopaeus as foundations for nests were all bare. 



SoMATOCHLORA PROVOCANS.— The spccics described under this name 

 in the News for February, page 39, is the same species as "Somatochlora 

 sp. near forcipata Scud." of my hst of New Jersey Odonata of 1900 (27th 

 Ann. Rep. N. J. St. Board. Agric, Suppl., p. 72, where, however, the date 

 is incorrectly given as Aug. 30, '92, instead of July 22, '92). — P. P. Cal- 

 vert, 



