The Cane Grubs of Australia. 
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FEEDING HaApits OF THE LARV. 
The grubs* appear to stand nearly in the same relation to the soil 
as do earthworms. That is to say, they are continually passing large 
quantit ies of soil through their bodies, altering to a certain extent, no 
doubt, its chemical nature and considerably changing its physical texture. 
This alteration is brought about by the fact that the organic matter of 
the ingested soil is partialh 4 digested and used as food while the soil 
is expelled from the anus in the form of a pellet. This constant moye- 
ment of soil through their bodies, combined with the loosening effect on 
the soil of locomotory movements of the legs and mandibles, must have in 
the long run an important effect on the character of soils in a grub- 
infested area. But, unlike earthworms, grubs do not to any extent 
transport soil from beneath to the surface. 
The following evidence has been collected to show that the grubs 
subsist largely upon the organic matter in the soil, attacking living 
vegetation at the same time but not constantly and habitually. 
Habitually and constantly, they are swallowing soil, extracting partially 
its organic content, yet a supply of living vegetation seems necessary for 
their normal development t= 
(1) Young larve when hatched are wholly white, and remain so 
until placed into bare soil, after which, in the course of a day 
or so, they become coloured—the colour due to soil which has 
been ingested. That they are not starved is shown by their 
erowth and appearance. 
(2) Larve kept in bare soil pass, for days at a time, large amounts 
of excrement. This would not be possible unless food was 
being obtained. 
(3) Larve kept in bare soil mixed with paris green invariably 
die after about three days. 
(4) Starved grubs have never been found in nature, though 
coming from bare soil or from some depth beneath the roots. 
of grasses. Larve obtained from a piece of Jand maintained 
for three months in a state of barrenness were as plump as 
usual, their food canals full of organie matter mixed with 
soil. 
(5) Grubs are healthy for several months in bare soil without 
access to living vegetation. 
(6) In cultivated canefields, the larve are often found in bare 
parts some distance away from living plants and apparently 
unable to reach same for several days at least. 
(7) Larve kept in pure sand or in empty glasses commence to 
shrivel after several days and to die after a week. 
(8) Grubs are not habitually and constantly attendant upon 
plants. 
(9) Examination of the food canal shows considerable variation 
in the nature of the contents, which always is a mixture of 
soil and organic matter of vegetable origin, the organic matter 
sometimes predominating, often the soil doing so. 
(10) Forbes (1907) states that Stiles has shown that a certain 
intestinal parasite of swine passes an intermediate stage 
* This refers to all species feeding on living vegetable matter and to most others. 
