Sept. 4. 1916 Life History of Army Cutworm 877 



much bare soil between the plants. A much -traveled road near by 

 probably did not account for the presence of the worms. It seems more 

 likely that the eggs were laid on the bare patches of soil in the alfalfa field. 

 There can be no doubt as to the specific identity of the moths that were 

 observed, for many taken in the act of egg laying were carried into the 

 insectary and placed in chimney cages, where they laid eggs in large 

 numbers. Larvae hatching from these eggs were reared to maturity, 

 and the moths were obtained and all identified as belonging to this species. 

 A few moths of other species were seen in the field during these obser- 

 vations, but none except C. auxiliaris were seen to deposit eggs. 



ATMOSPHERIC TEMPERATURE DURING OVIPOSITION 



No very definite temperature limits to oviposition can be stated. 

 Thermometers were taken into the field and observed from time to time 

 as the moths were being watched. The temperature during the rapid 

 oviposition generally ranged between 55 and 70 F. A temperature of 

 6o° to 70 at 4 or 5 o'clock p. m., with little or no wind stirring, insured 

 great activity of the moths. When the sun set, the temperature dropped 

 rapidly, and the moths sought shelter under clods and in cracks in the 

 soil, very few being found still active in a temperature between 45 ° and 

 50 . Egg laying ceased at about 40 , though the moths were seen to 

 fly at lower temperatures if disturbed. Whether or not the moths would 

 continue active after dark if the temperature were favorable can not be 



DESCRIPTION OF THE EGG 



Viewed from above, the egg is circular in outline; but when viewed 

 from the side, it is very nearly elliptical, the shape varying from an 

 ellipse only by being slightly flattened on the side on which it rests, which 

 is opposite the micropile. It measures 0.62 mm. in diameter by 0.52 mm. 

 in height. The color when the egg is first laid is white tinged with yellow, 

 but before hatching the dark embryo shows through, giving the effect of a 

 darker color. Surface markings on the chorion are very obscure. They 

 are invisible under a hand lens magnifying 16 diameters. W r hen viewed 

 by reflected light under a compound microscope or under the high power 

 of a binocular microscope, a very faint reticulation may be seen. This 

 is more distinct in the shells of hatched eggs, in which the pattern often 

 may be very clearly seen. No ridges radiating from the apex or upper 

 part of the egg, such as may often be seen in noctuid eggs, have been 

 found in this species. 



EGG-LAYING HABITS IN CONFINEMENT 



The moths taken into the insectary and put in cages were quite irregu- 

 lar in their egg laying. In general, two or three days were passed with- 

 out laying eggs; then a large number were laid within a few hours, after 

 which the moths soon died. Clover blossoms were placed in the cages, 



