352 Phylum Arthropoda 



them. Normally these moths move about at night but sit motionless 

 throughout the day. Thus, their natural characteristics lend them ex- 

 cellently to handling unanesthetized. The apparatus for handling con- 

 sists of the "moth dipper," a quantity of % x %-inch shell vials and of 

 the cardboard milk bottle caps. The dipper may easily be made by 

 gluing one of the % x %-inch vials to a wooden tongue depressor, or 

 any strip of wood whittled down to about % x % x 6 inches. It is used 

 to "dip" the moth from a piece of comb, or from the walls of the culture 

 bottle. This is done by gently placing the dipper over the moth and 

 moving it slightly. This generally will cause the moth to shift in one 

 movement to the side or bottom of the dipper and remain there, and it 

 may thus be moved to any part of the room or to the binocular for 

 examination. If the dipping causes the moth to become irritated, one 

 may slide the dipper up the side of the culture bottle to its top, then 

 slip the thumb of the same hand over the mouth of the dipper, thus 

 confining the moth. It has proved to be a saving of time to transfer the 

 irritated moths to the % x % vials and invert each of these on a milk 

 bottle cap. In a few minutes the moths ordinarily will come to rest on 

 the milk bottle cap. Once the moth becomes quiet the vial may be 

 removed and the moth taken to the binocular or handled in any way 

 desired. 



LABORATORY BREEDING OF THE EUROPEAN CORN 

 BORER, PYRAUSTA NUBILALIS* 



CONSIDERABLE time has been devoted to the development of a 

 technique for rearing larvae of the European corn borer, Pyransta 

 nubilalis, in quantity. This work was necessary for the breeding of 

 parasites working on the first instars of the borer, such as Microgaster 

 tibialis. 



All material is incubated at a temperature of 85 ° F. with a relative 

 humidity of 60% or higher. This has been found to provide optimum 

 conditions of propagation. 



Full grown larvae collected in the field are used to rear moths for egg 

 production, since all the young larvae reared in the laboratory are used 

 in the parasite breeding. The cages that are now used for this purpose 

 have proven to be very satisfactory and are, at the same time, very simple. 

 They consist of lantern globes closed at both ends with fine mesh wire 

 screening to facilitate air circulation, and strips of corrugated cardboard 

 one inch wide which are placed side by side in a single row across the 

 diameter of the globes so that they form a partition. 



The full grown borer larvae are put into the globe and crawl into the 



♦Reprinted, with slight changes, from Canad. Ent. 61:51, 1929. by L. J. Briand, 

 Parasite Laboratory, Belleville, Ontario. 



