476 
Journal of Agricultural Research 
Vol. VII, No. ii 
Outlines showing methods of sequence of the autumn forms of Macrosiphum granarium 
First method: 
Parental t e J^ orms °f ^ rst generation off-JForms of second generation 
^ spring. | offspring. 
Pinkish nymphs, becomingfYellow, wingless oviparous fe- 
winged viviparous females. I males only. 
Deep-pink nymphs, becoming 
winged males only. 
Pinkish wingless 
: viviparous fe¬ 
males. 
Second method: 
Parental type... 
Pinkish wingless 
viviparous fe¬ 
males. 
(Forms of first generation off-JForms of second generation 
I spring. | offspring. 
a. Yellow, wingless oviparous 
females only; 
or 
b. Wingless viviparous females 
only; 
or 
c. Winged and wingless vivip¬ 
arous females; 
or 
d. Yellow, wingless oviparous 
females and winged and 
wingless viviparous fe¬ 
males. 
B. Pinkish nymphs, becomingl winged males and winged and 
A. Pinkish nymphs, becoming 
winged viviparous fe¬ 
males. 
wingless viviparous fe-: 
males. J 
C. Deep-pink nymphs, becom¬ 
ing winged males only. 
wingless viviparous females. 
It will be seen, therefore, that in a single cage there may be green, 
slightly pink, deep-pink, and pale-yellow individuals—quite a wide 
range in color for a single species. 
INFLUENCE OF TEMPERATURE ON PRODUCTION OF SEXES 
During the first week in October, 1912, pinkish forms were plentiful 
in the stock cages and the sexes had begun to appear sparingly. A 
large number of pinkish individuals that showed promise of producing 
the sexes were isolated and placed in one of the greenhouses of the 
Purdue Experiment Station to hasten the production of the sexes and 
that more data on the progeny of the pink wingless females that appear 
at this time might be gathered. The greenhouse was kept at a tem¬ 
perature between 50° and 70° F., and the writer thought that since the 
sexes had begun to appear their numbers could be rapidly increased by 
placing them in a warmer temperature. Almost the opposite effect was 
produced. A number of males but only a very few oyiparous females 
appeared. The ones that were obtained were probably born just before 
or very soon after they were placed in the greenhouse. A stock cage 
that was left outdoors produced quite a number of oviparous females and 
