12 BULLETIN 539, U. S. DEPARTMENT OF AGRICULTURE. 



SEASONAL HISTORY. 



OVIPOSITION. 



Eggs of this species have not been found in the field; but, judging 

 from the results obtained from rearing, they are probably deposited 

 on the stems of plants, in the axils of the leaves, or on the ground 

 at or near the bases of the stalks. The larvae upon hatching crawl 

 to the stalks and begin feeding. 



In rearing cages, the eggs are deposited generally on the cheese- 

 cloth which covers the lantern globe. Sometimes, however, they 

 are deposited on bits of grass leaves or stems, pieces of cloth or other 

 loose material placed in the bottom of the cage, on the stem of grass 

 placed in the cage as food or, not at all infrequently, upon the cotton 

 which holds the sprig of grass in place. Most of the eggs deposited on 

 the cloth top are pushed through the mesh of the cloth by the female 

 and are found on the upper side of the cloth, appearing as though 

 they were deposited from without. Eggs are placed singly as a rule, 

 though sometimes two or three en masse may be found glued securely 

 together. In such cases they lose their individual rotundity and 

 flatten out somewhat at points at attachment. A mucilaginous sub- 

 stance secreted by the female, which hardens after exposure to the 

 air, glues the eggs firmly to the object. 



The females begin to oviposit shortly after dusk and continue 

 until the early hours of the morning. The majority of the eggs are 

 deposited during the forepart of the night and it is probable that all 

 of them are laid at this time under field conditions. No eggs are 

 deposited during the day or in bright light at night. Oviposition 

 will take place, however, in diffused light, although not as many 

 eggs will be deposited as in total darkness. 



EFFECT OF TEMPERATURE ON OVIPOSITION. 



Oviposition did not take place when the temperature fell much 

 below 80° F. Two cages containing a number of females and males 

 were kept under normal conditions ; three others, also supplied with 

 a number of moths of both sexes, were kept in a room the temperature 

 of which rose to somewhere between 80 and 90° F. during the day and 

 fell gradually, reaching approximately 80° F. by early evening and 

 practically normal by morning, as the windows were kept open all 

 night. Eggs were obtained in all the cages kept in the room, all 

 of them being deposited during the early part of the evening. No 

 eggs were obtained in the cages kept under normal conditions. 

 The same type of cage was used in both cases, consisting of a flower- 

 pot surmounted by an ordinary lantern globe, the top of which was 

 closed with a bit of cheesecloth held in place by a rubber band. 



