1 74 
TRANSFORMATIONS OF INSECTS. 
of crawling down the rose stem into the ground on the approach 
of winter, and of hybernating in the cocoon at the base of the 
little tree, should suggest the propriety of raking and thoroughly 
disturbing the superficial mould. By these means the cocoons can 
be easily seen and destroyed. There is another plan, which is not 
so ready however, and it is to notice where the eggs are laid, and 
to paint the twig over with some viscid liquid that will fill the 
cracks, and seal up the unfortunate larvae quite hermetically. 
The rose saw-flies do not live in common, and each one makes 
its own cocoon. In the Brazils, however, there is Hylotoma 
formosa y which, according to Sichel, makes a nest in which many 
participate. 
The Tenthredites are the most numerous of the saw-fly family, 
and they may be recognised by their antennae not being swollen 
and not having less than from nine to fourteen distinct joints. Their 
habits and metamorphoses resemble those of the Hylotoma , and 
it is, therefore, only requisite to select a few examples where 
there is a shade of difference, and where the structures of the 
insect are evidently modified for a purpose. 
The Athalia are small insects, and their colour resembles 
that of the Hylotoma generally speaking, but their antennae are 
sufficiently distinct as regards their construction to prevent the 
genera being confounded. They are finely pectinated in the 
male Athalia , but they are not composed of more than from 
nine to ten joints, and this is the case in both sexes. 
Athalia centifolia , so well known to English entomologists, 
from Newport’s magnificent descriptions and studies, is one of the 
commonest species. The larvae are of a greenish black colour 
and have eight pairs of membranous legs. They occasionally 
are to be found in great numbers on culinary vegetables, which 
they eat and waste remorselessly. United in numerous groups 
upon each plant, they devour the leaves and even the tenderest 
twigs. A closely allied species ( Athalia spinarum) attacks cru- 
ciferous plants, and does a great deal of damage during certain 
years. The larvae of these small saw-flies undergo their meta- 
morphoses in the earth, and as they have not much silk at their 
command they agglutinate earthy particles together, and make 
a rude sort of cell or cocoon. 
