INDEX, 149 
Page. 
Goldfinch. (See Astragalinus tristis.) 
Grain-aphis, spring (see also Toxoptera graminum) . 
aberrant individuals 81 
age at which females begin reproducing 70-71 
ant enemies 136 
attack, character 44 
bird enemies 135 
birth of young 63 
confusion with Nacrosiphum, granaria 13, 23 
description of different instars 58-59 
summer forms 59-61 
diffusion, influence of temperature thereon 88-94 
winds thereon 81 
distribution in the eastern hemisphere 16-18 
western hemisphere 18-19 
earliest observations in America 13-16 
early records in Europe 16 
egg, description 95-97 
embryology 94-103 
observations 97-102 
summary 102-103 
enemies 103-136 
miscellaneous 135-136 
fecundity of oviparous forms 81 
viviparous female 73-75 
wingless versus winged females 75-76 
first generation, fifth instar or adult stem mother, descrip- 
tion 58-59 
first instar, description 58 
fourth instar, description 58 
second instar, description 58 
third instar, description 58 
food plants 41-43 
fungous enemy 136 
generations, number 52-57 
per year 63-70 
literature consulted 144 
longevity 72 
of sexes 80 
losses from depredations in 1907 39-40 
methods and material for embryological studies 95 
migratory female, description 60 
molting 61-62, 78 
number of generations per year 63-70 
molts 61-62 
oviparous development 78-81 
female, description 77-78 
forms, fecundity 81 
oviposition, age begun by females 78-79 
period 79-80 
place 79 
outbreak of 1890 : 19-24 
1901 24 
