THE DARK-GREEN GRASS CATERPILLAR. 105 



that u in damp, low-lying ground, the holes will 

 frequently be found to have a small tunnel, proceeding 

 at right angles from the bottom of the shaft." These I 

 have not seen, the tunnels examined having been in dry 

 ground. 



From the mouth of the tunnel, a sort of covered way 

 is constructed above ground ; this is roofed with bits of 

 dry grass and excrement cemented together with silk. 

 It seldom stands more than six inches from the tunnel, 

 and the grubs seldom go more than six inches from its 

 exit. On being alarmed, although they proceed back- 

 wards, they never fail to reach its entrance. Heavy 

 rain destroys these outer covered ways, so that the 

 entrances to the tunnels are exposed. If the grubs are 

 not fully fed, the damage is repaired at night time ; but, 

 if they are fully fed or have changed to pupae, the holes 

 are left exposed. 



With regard to the larvae of this moth eating the 

 roots of the grass as well as the tops, Mr. Lea combats 

 my statement, and, taking everything into consideration, 

 I feel sure* he is right, as I find the roots eaten only 

 when the grubs are in captivity, or, if of a paler color than 

 the typical grub itself, namely, with a new skin or from 

 the moult. It has also been stated by Mr. Lea that he 

 has never yet found a parasite on the larvae of this moth ; 

 but I have found one (see Fig. VI. ) on a partly shrivelled 

 grub of this moth, and another kind of fungus was also 

 found (see Fig. VIA.) on a grub found in the vicinity 

 and in the same patch of soil, so I feel convinced that 

 these dark green grubs are by no means immune 

 from the attacks of either fungus or diseases of a 

 bacterial growth. 



In alluding to diseases among larvae, I may mention a 

 case which occurred two years ago in the Bacchus Marsh 

 district of Victoria, which went to show that some 

 diseases, whether they be of bacterial origin or otherwise, 

 are wonderfully fatal to caterpillars. It was found that 

 large numbers of small grubs were eating off the grass, 



