582 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
can be used successfully in other regions and with other species. It is 
hoped that this paper will answer satisfactorially in part the many in¬ 
quiries received during the last year or two from economic entomologists 
regarding the methods of rearing wireworms. 
The meeting was adjourned to meet next year with the Pacific 
Division, American Association for the Advancement of Science. 
MIGRATION—AN IMPORTANT HABIT OF THE EUROPEAN 
CORN BORER ~ 
By Geo. W. Barber, Cereal and Forage Crop Insect Investigations , Bureau of 
Entomology , United Spates Department of Agriculture 
Abstract 
This paper deals with the migratory habits of the European corn borer ,Pyrausta 
nubilalis Hubn.,in the heavily infested area of Massachusetts. Evidence obtained from 
study of the insect in the field is presented, showing that the larvae sometimes migrate 
in large numbers, particularly from over-populated corn stalks. It is shown that this 
movement is greatest on the warm nights of late summer. Over-wintering of larvae 
in locations, other than the host plant, is discussed. 
This information has a distinct and important bearing on the field measures used 
to reduce the number of this insect. If larvae migrate in appreciable numbers from 
host plants before such infested plants are destroyed, and find hiding places where 
they successfully pass the winter, the effectiveness of such control measures may be 
greatly reduced. Knowledge of the hiding places of migrating larvae is important 
so that more effective control measures may be found. 
The migratory habit of the European corn borer (Pyrausta nubilalis 
Hubn.) is important, becoming very important when the insect is 
particularly abundant. In such cases, should a large number of indi¬ 
viduals leave the food plant in which they had been feeding to seek other 
or fresher food, to seek more advantageous winter quarters, or because of 
an over-population of larvae for which the food is inadequate, the effec¬ 
tiveness of control measures such as the destruction of crop remnants 
may be considerably reduced. If these migrating larvae find conceal¬ 
ment in unexpected or unusual places a sufficient number may survive to 
produce a destructive infestation the following year, notwithstanding 
that the “clean up” campaign has been waged with apparent thorough¬ 
ness and care. 
During 1922 in eastern Massachusetts an excellent opportunity ex¬ 
isted for the study of this important subject. During August and 
September of that year when larvae of the second generation were 
present in the field, individuals were more abundant than at any 
