THE EICE MOTH. 7 



30, and in the meantime the rice moth and other pests developed and 

 the rice was condemned by the United States Government. Finally, 

 the rice was shipped to Xew Orleans to be reconditioned, and was 

 put into a condition satisfactory to the Federal authorities. 



December 7 of that year, a chocolate firm in Pennsylvania, which 

 previously had furnished specimens, wrote that the moths disappear 

 with the arrival of cold weather and are not seen again until the 

 following spring. During the late spring months and all summer 

 they are in evidence. The greatest trouble is experienced from the 

 laying of eggs by the moths on the finished chocolate and cocoa. The 

 eggs hatch into larvae and the customer naturally objects to " wormy " 

 goods. Attempts were being made to avoid this as much as possible 

 by keeping finished materials covered. 



LIFE HISTORY. 



The complete life history of the rice moth has not been ascertained. 

 The progress which might have been made with other insects in 

 similar investigations was prevented in this case by the fact that 

 seldom more than two generations were obtained in a single rearing 

 jar of cocoa or related substances. When confined in large numbers 

 the larvae, like others of similar habits, such as Ephestia, travel, evi- 

 dently in an endeavor to secure a suitable location for transforma- 

 tion to pupae, to a greater extent than do the other species. This might 

 explain the fact that the pupal cases or cocoons usually are found 

 either on the outside of the bags at point of contact in the piles, or in 

 the folds of the burlap sacks, which provide more or less shelter. In 

 the rearing jars, although small pieces of cloth were inserted to form 

 shelters for the pupae, the thick webbing spun by the larvae com- 

 pletely covered the infested material, preventing the exit of the 

 moths, which died without being able to reproduce. This fact is 

 mentioned because it happened in the case of a half dozen rearing 

 jars of large size (about 8 liters capacity). 



It has been ascertained, nevertheless, that the insect requires only 

 a short time to develop from lar^^a to adult, this period being de- 

 dependent on temperature. The entire summer period for trans- 

 formation from egg to egg is between 28 and 42 days, or from 4 to 6 

 weeks, but this period would be prolonged considerably in cooler 

 weather. 



Better results attended rearing experiments with this species in 

 infested rice from Porto Rico. From a lot of moths which deposited 

 eggs about May 26 a new generation of moths began to issue July 8, 

 this period having been passed in 43 days, or approximately 6 weeks. 

 The temperature ranged from 52° to 82° F., reaching the maximum 

 only on a few occasions, and the average or mean temperature for 

 the experiment was from 68° to 70° F. 



