34 



INJURIOUS INSECTS AND FUNGI. 



[.Tune 1895. 



the cereal exhibits of Guatemala, Costa Rica, Mexico, Trinidad, 

 Cura^oa, British Guiana, Brazil, Paraguay, Uruguay, Ecuador, 

 ond the Argentine Republic, also in those of the Cape of Good 

 Hope, Liberia, Orange Free State, Tunis, Siam, Ceylon, and 

 Australia, as well as in the show cases of the exhibits of some 

 of the American States. The grain exhibits were shown in 

 cases covered with glass and were practically weevil-proof, but 

 when the weevils, which had been brought in the grain in 

 larval, or pupal, state, appeared in due course, some of the 

 United States exhibitors suggested that they had got into the 

 cases after their arrival at Chicago. On this point Professor 

 Riley says : — "The fact that the exhibitors in char«Te of these 

 exhibits protested that the weevil was unknown in their respec- 

 tive States counts for naught, since it is a well-established fact 

 that this particular species — rice weevil — is of common occurrence 

 in every state and territory of the Union." 



Both of these species of Sitophihis are found in granaries and 

 corn stores in Great Britain and are equally destructive. It is 

 rather difficult to distinguish between the Sltophilus granaria 

 and the Sitophilus Oryzce without a magnifying glass, but there 

 is no doubt that they are both present in nearly equal propor- 

 tions in this country, and that they do an air^ount of harm, that 

 is in no degree realised, to grain stored for considerable periods. 

 The weevils in suitable circumstances breed continuously, one 

 generation succeeding another with remarkable rapidity, so that 

 in a heap of grain stored for some time under conditions favour- 

 able to the propagation of these insects enormous loss of weight 

 and quality may be sustained. This injury may often be unsus- 

 pected unless particular observation is directed to the grain 

 when the heaps are moved and turned. The weevils attack all 

 kinds of corn and malt, but wheat seems to be their favourite grain. 



In the course of a recent examination of a sample of white 

 wheat from Australia it was found that at least 85 per cent, of 

 the grains were either actually infested or had holes in them 

 from which the weevils had emerged, or which h id been made 

 by the weevils in quest of food. In this sample there was about 

 an equal number of both species of Sitophilus, 



Life History. 



The BitopMlus granaria is rather more than the eighth of an 

 incii long, varying in colour from dark red to black. It has 

 a long snout, and its anteunae have elbows with a small oval club 

 at each end. The six legs and antennae are red. The thorax is 

 somewhat long and has rows of dots upon it. A single egg of a 

 dirty white hue is placed by the female weevil in a grain of 

 wheat, or other grain, after a hole has been bored in it to receive 

 the egg. After the egg is deposited, the female covers the hole 

 with a sticky transparent substance, so that it is difficult to 

 detect it without very careful inspection. A female will lay 

 from 100 to 150 eggs, not all at once but during seveiYil weeks 



