132 NEW ZEALAND NATURE-STUDY BOOK 
The pupa stage may last for a few weeks only, when 
another brood of moths issues forth to work further harm, 
or it may continue through the winter. Most of the 
larvae however remain in their cocoons until the following 
year. 
The forms referred to in the following very briet account 
are amongst the most destructive and formidable of our 
insect pests. 
Many kinds of Beetle, large numbers of which are 
to be found almost everywhere, do a great deal of harm 
both as larvae and fully developed insects. Their larvae 
are usually buried in the ground and are very destructive 
to the roots of grass or growing crops. In the final stage 
by means of their hard biting jaws they are able to devour 
the leaves and blossoms of plants. 
Wire worms, which are really the larvae of the 
Click-beetles, devour the roots and stalks of plants, 
and, as they wander about from one plant to another, 
destroy far more than they eat. Unlike leaf-eating larvae 
they live for three years or more. 
The Turnip-flea, or Turnip Flea-beetle, is a small active 
creature sometimes found in vast numbers on turnip crops 
if the conditions be favourable, 7.¢., if the soil be dry. It 
may be recognised by its power of leaping into the air, 
often for a foot or more, also by the broad yellowish stripe 
‘which runs lengthwise upon each wing-cover. The Flea- 
beetle feeds on the leaves of both wild and cultivated 
cruciferous plants, being frequently found where turnips 
have never been grown though it thrives best where crops 
of this annual furnish it with food. Its eggs are laid on the 
under side of the leaves, and are deposited singly. The 
larva is a leaf-miner, burrowing into the soft tissue and 
leaving a discoloured track behind. It feeds for about 
seven days, then descends for a few inches into the ground, 
