104 DESTRUCTIVE INSECTS OF VICTORIA: 



probably the number of eggs laid varies according to 

 the amount of food consumed by the larva." 



The pupa (see Fig. III.) is of a light brown color, with 

 the skin covering the head parts of a darker brown. It 

 is well-known that these grubs construct tunnels in the 

 ground, and as a rule very close to the surface. 



In the Journal of the Council of Agriculture, Tasmania, 

 Mr. Box, as quoted by Mr. Lea, states: " In the month 

 of June I found them, the grubs, just under the surface 

 of the ground, about half an inch long. In July and 

 August they had increased in size to an inch and a half, 

 burying themselves in the ground, and covering their 

 holes with a web." 



It is, Mr. Lea says, extremely probable that the grubs 

 wander considerably, and that no other tunnel is 

 constructed. From the time the grubs are three-fourths 

 fed till their final change, however, I am convinced that 

 each grub inhabits only one tunnel. This opinion is 

 held for several reasons, which may be stated as follows: 

 The tunnel is often of great length, and constructed in 

 very hard ground ; the grubs feed solely at night time, 

 and never far from the mouth of their tunnel ; no grit 

 is to be found in their intestines ; when badly infested 

 land is ploughed out, the land in the vicinity does not 

 become more infected than previously ; the prevalence 

 of cannibalism, and the fact that patches are eaten bare 

 and constantly kept bare. 



The tunnels are seldom wider than a lead-pencil, and 

 vary in length according to the hardness of the ground. 

 In hard ground, I have seen the tunnels from three to six 

 inches long, usually about four inches ; in soft ground 

 they are seldom less than nine inches in length, and 

 frequently are more than a foot. Where food is 

 abundant the tunnels are heavily lined with silk ; but, 

 where the food is poor, the silk is much less in 

 evidence. The tunnel is usually at an angle for the 

 first half-inch ; but after that generally goes straight 

 down, or with a slight curve. Mr. Thompson states 



