88 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



Commenting on the effect of humidity on the emergence 

 from the soil of adults of grape root-worm and plum curculio 

 Mr. Johnson stated that his observations in rearing plum 

 curculio in 1906 showed that emergence of beetles was re- 

 tarded and in some cases prevented by withholding moisture, 

 whereas in adjacent cages where moisture was supplied a 

 maximum number of beetles emerged several days earlier. 

 In the case of the emergence of adults of the grape root-worm 

 it was observed in 1907 that a period of dry weather occurred 

 during the first two weeks in July, which is about the normal 

 time of the emergence in maximum numbers of the beetles 

 in vineyards. Up to July 14 but very few beetles emerged, 

 though in digging they could be found in their cells in the dry 

 soil. Heavy rains fell on the 14th and during the following 

 two or three days the adults emerged in large numbers. This 

 emergence in the field corresponds with the cage experiments 

 in which moisture was applied and withheld. 



Mr. Woglum mentioned the effect of hot dry weather on 

 retardation in the emergence of adults of Aleyrodes citri in 

 India. Practically matured pupse remained dormant during 

 a continued hot dry period of ten weeks (July-August, 1911, 

 temperature 85 to 120 F.) but emerged within a week fol- 

 lowing first rain. 



-Under the title " An Old Question," Mr. Rohwer discussed 

 briefly, the matter of local lists. The following is his abstract : 



Local lists may be divided into two classes : (a) geographical 

 lists, or lists treating material collected within a certain 

 definite geographical or political boundary; (/>) biological 

 lists, or lists treating material collected within a definite 

 faunistic area. For the purpose of studying geographical 

 distributions biological lists are more useful. 



With the exception of Coleoptera, Neuroptera, and spiders 

 very little has been done in the way of forming a local list of 

 the insects of the District of Columbia and environs. The 

 following papers are the only ones known which deal wholly 

 with material collected in the above-mentioned locality. 

 From time to time various new species have been described 

 or recorded from this area, but none of these papers deal 

 with this area alone. 



