578 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 17 
SIMPLE METHODS OF REARING WIREWORMS (ELATERIDAE) 
By M. C. Lane, Junior Entomologist , Cereal and Forage Insect Investigations 
U. S. Department of Agriculture 
Abstract 
It is the purpose of this paper to record a few successful and simple methods of 
rearing one of the most difficult groups of insects with which the economic ento¬ 
mologist has to deal, namely wireworms of the family Elateridae. The writer’s studies 
and experiences have been confined mostly to two species, Ludius noxius Hyslop and 
Pheletes occidentalis Candeze of Washington State, but since these two species exist 
under a great variety of conditions from very dry to very wet, it is felt that the sug¬ 
gestions regarding methods and rearing here given can be adapted for other species 
in other sections. 
In rearing subterranean larvae, such as wireworms it is almost a 
necessity to have some sort of an underground or cellar laboratory. 
Of course an underground chamber fitted with extensive temperature 
and humidity control apparatus would be ideal, where the expense could 
be afforded at some permanent research laboratory. But for all prac¬ 
tical and general purposes a house or outside underground root cellar 
will answer very well. The latter is ideal in situations where there is 
good drainage and may be constructed .with side walls of boards, a dirt 
floor, double doors, and a roof covered with sods. If shelves and a table 
with a light are installed, the different stages of the wireworms can be 
handled without fear of injuring them from lack of humidity or through 
extremes of temperature. Humidity and temperature usually remain 
about the same as are normally found from four to ten inches deep in the 
soil, varying about the same or very little from day to day. In the case of 
a laboratory situated in a house cellar made of cement, it would prob¬ 
ably take some practice to maintain the proper amount of humidity and 
temperature. A separate small room in the north corner of a large 
cellar would seem to offer the best solution. 
Adult elateridae can usually be procured in the fields by sweeping in 
the early spring, especially along the fence rows and ditch banks. It 
usually takes several consecutive warm days with temperature over 70 
degrees F. to bring the adults from their winter cells, but when the 
weather once becomes permanently warm the adults will emerge and fly 
actively on sunny calm days for a week or two, after which the emer¬ 
gence is over till another year. 
The obscure habits of the female adult elaterid and her apparent in¬ 
aptitude to fly and expose herself as freely as the male, makes the pro¬ 
curing of sufficient females for rearing purposes difficult. In order to 
make sure of a supply of female adults, it was found necessary to rear 
