That of the maturer larva is no better known.

Nothing is more common, while digging in the fields to any depth, to find these impetuous excavators under the spade; but to surprise them fixed upon the roots which incontestably nourish them is quite another matter.

The disturbance of the soil warns the larva of danger.

It withdraws its proboscis in order to retreat along its galleries, and when the spade uncovers it has ceased to feed.
If the hazards of field-work, with its inevitable disturbance of the larvae, cannot teach us anything of their subterranean habits, we can at least learn something of the duration of the larval stage.

Some obliging farmers, who were making some deep excavations in March, were good enough to collect for me all the larvae, large and small, unearthed in the course of their labour.