344 Phylum Arthropoda 



The geotropic method of collecting the moths may also be used with 

 the "tilted bin" unit (Fig. 66). Instead of hanging loosely, the cloth 

 across the front of the stacked trays should be stretched taut and 

 fastened securely about % inch away from the trays. The enclosure 

 thus formed should open at the top and at the bottom into sheet iron 

 funnels. The base of each funnel should be % inch wide and as long 

 as the width of the stack, and the small end of each funnel should fit 

 into the opening of the moth trays. 



The temperature and humidity in the rooms housing the production 

 units should be regulated so that the air surrounding the kernels in the 

 mass of grain will range in temperature between 75 ° and 85 ° F., and in 

 humidity between 60% and 70%. Such humidities provide optimum 

 hygroscopic moisture for the development of the insect larvae, and the 

 temperatures mentioned result in the most rapid succession of genera- 

 tions. 



The activity of the larvae themselves is a source of heat that raises the 

 temperature of the grain mass higher than the surrounding air (heat of 

 infestation). If the grain is not permitted to heat as a result of ex- 

 cessive moisture (heat of respiration) the status of the infestation may 

 be roughly gauged by taking the temperature of the mass. The tempera- 

 ture of the room housing the production units should be comparatively 

 low. 



Reference 



For the culture of the Angoumois grain moth see also p. 497. 



Bibliography* 



Bailey, C. H. 1921. Respiration of shelled corn. Univ. Minn. Agric. Exper. Sta. 

 Tech. Bull. 3. 



Flanders, S. E. 1927. Biological control of the codling moth. J. Econ. Ent. 

 20:644. 



1929. The mass production of Trichogramma minutum Riley and observa- 

 tions on the natural and artificial parasitism of the codling moth eggs. Trans. 

 Fourth Inter. Congress Ent. 2:110. 



1934. Sitotroga production. J. Econ. Ent. 27:1197. 



Peterson, Alvah. 1934. A Manual of Entomological Equipment and Methods. 



Part I, plate 137, fig. 1-4. 

 Schread, J. C, and Garman, P. 1933. Studies on parasites of the Oriental fruit 



moth. Conn. Agric. Exper. Sta. Bull. 353:691. 

 Simmons, P., and Ellington, J. W. 1932. A biography of the Angoumois grain 



moth. Ann. Ent. Soc. Amer. 25:265. 



*Post script: Since the completion of this Compendium there has appeared Circular No. 

 376, U. S. Department of Agriculture: New Equipment for Obtaining Host Material for 

 the Mass Production of Trichogramma minutum, an Egg Parasite of Various Insect Pests, 

 by Herbert Spencer, Luther Brown, and Arthur M. Phillips, all of the U. S. Bureau of 

 Entomology and Plant Quarantine. 



