Semi-Centennial Volume. 79 



A summary of the results of the two examinations, including per- 

 centages of the proportionate number of live, dead and total stages 

 found according to species, is presented in the following tabulation: 



Name of species. Stages alive. Stages dead. Total. 



Rhizopertha dominica 107 = 5.78+% 1,579 = 85.35 + % 1,686 = 91.14 — % 



Latheticus oryzce 12 = 0.65 — % 53= 2.86+% 65= 3.51+% 



Sitotroua cerealella 9 = 0.48 + % 25= 1.35+% 34= 1.83+% 



Lophocateres pusUliu 21 = 1.14 — % 5= 0.28 — % 26= 1.41 — % 



Calandra oryza 1 = 0.05 + % 18= 0.97 + % 19= 1.03 — % 



TriboUum novate = 0.00% 10= 0.54+% 10= 0.54+% 



L(rmophln'U8 mintitvs 5 = 0.28 — % 2= 0.11 — % 7^ 0.38 — % 



Tenebroides maurUanicus = 0.00% 3= 0.16+% 3= 0.16+% 



Grand totals 155 = 8.38% 1,695 = 91.62%. 1,850 = 100.00% 



The whole number of 1,850 visible stages of the more important in- 

 festing insects actually counted in three pounds of rough rice grains 

 gives a quota of approximately 617 stages of the pests per pound. Ap- 

 plying this computation to the stock in storage, every 100 pounds of the 

 grains at the time of the second examination of the sample would be very 

 apt to contain not less than 61,700 living and dead insects, all likely 

 occurring in the adult stage alone. Consideration of eggs, larvae and 

 pupae would consequently be in addition. By calculation, however, only 

 8.38 per cent of the stages were found alive. The proportion of dead 

 ones therefore came to 91.62 per cent. 



While these figures afford a basis for comprehending the degree of 

 infestation, they fall far short of a true estimate because of the impossi- 

 bility of detecting and accounting stages concealed within the grains. 

 Then the probable escape of many individuals from the stock befoi*e the 

 sample was obtained, together with other obliterative effects, leaves the 

 question of what would be the full extent of occurrences of the pests in a 

 given time entirely open to speculation. 



Since the stock was said to have been grown during the season of 1910, 

 its age from the time of harvesting to June, 1912, covered at least twenty 

 months. The aggregate of the above counts evidently represents a large 

 rather than a small proportion of the entire number of individual pests 

 that had accumulated from infestation extending over this period. The 

 great quantity of dead insects was doubtless due to the dying off of 

 generations, particularly during and after the last winter. Most of the 

 dead adults found by the second examination may reasonably be regarded 

 as having been over-wintered specimens, and the live examples were 

 judged to be representatives of a new seasonal generation. These deduc- 

 tions, of course, must be supported by definite particulars concerning the 

 term of life and behavior of the different species involved. Such data 

 will be presented in accounts of the life history of each species that was 

 studied. 



THE ANGOUMOIS GRAIN MOTH. 



(Sitotroffa cerealella 01! v.) 

 REM.\RKS ON OCCURRENCES. 



According to the status derived by examinations of rough Honduras 

 rice obtained in a general warehouse at New Orleans, La., January 17, 

 1912, only thirty-four individuals representing the Angoumois grain 

 moth were found in the sample of grains weighing three pounds. On 



