218 TRANSFORMATIONS OF INSECTS. 
begins to suck the animal juices. The young Scola grows 
rapidly, and day by day the beetle larva becomes smaller and 
smaller, in consequence of being continually sucked. By the 
time that it has become completely exhausted, nothing else but 
the skin remaining, the larva of the Sco/ia has attained its full 
growth. It then spins a thick cocoon of a brown colour inside 
the skin, which is all that is left of the beetle larva; so that this 
unfortunate creature affords food to the Sco/ia in the first part of 
its life, and a certain amount of protection and covering during 
metamorphosis. The Scolza passes the winter in its cocoon, and 
undergoes its transformation into a nymph during the spring, but 
the perfect insect does not break forth until the commencement 
of June. 
In the engraving a male and female Scola will be noticed, 
the one on the leaf and the other in flight. Immediately under- 
ground in a cell is a larva of the beetle Ovyctes nasicornis on 
its back. The small larva of the Scola has its head forced into 
the body of the beetle larva. Below, and on the right hand, is a 
cocoon which will be seen to rest inside what is left of the beetle 
larva; and on the left the nymph of the Scolia is shown within 
its cocoon. 
In the Seychelle Islands, and in Madagascar, there are some 
species of Ovyctes the individuals of which attain a great size; 
they do a great deal of harm to the cocoa-nut trees, and thus 
cut off one of the most important sources of food in tropical 
countries. There are two kinds of larve of the genus Scola 
which eat and destroy the larve of these beetles, and which are 
metamorphosed exactly in the same manner as the European 
Scolia. 
The Sher is a well-known insect, and belongs to a genus 
which is closely allied to Scola, and is commonly called the 
Sand Wasp. They are generally of considerable size, and their 
colour is of a brilliant violet blue, more or less deep, and some © 
of them are marked with bands of yellow. Species are found 
scattered over all parts of the world, especially in warm climates, 
but only one is found in Great Britain. These Hymenoptera 
are remarkable for their activity and also for the elegance of 
their shapes. There is one which has yellowish wings and a red 
