REPORTS BY THE HONORARY SCIENTIS'S. 195 
The tunnel made by the larva is curved or circular. The young 
grub bores in the softer sap-wood, but as it grows goes deeper, and 
in the second season curves outwards again towards the surface, 
so as not to leave too great a thickness of wood to be bored 
through by the imago when ready to escape. The tunnel may 
be as long as 8 inches, and the hind part of the burrow is 
stuffed with frass. When full fed the larva makes a chamber in 
which it pupates, and when the wood-wasp is fully developed, it 
gnaws the round hole by which it emerges. The generation lasts 
never less than two years, and is often longer, there being a 
number of cases on record where the wasps have issued from 
worked timber forming floors, etc. 
The jaws of the larve are very strong. They are known to 
have bitten through lead-piping, and Blandford relates that at 
the time of the Crimean War bullets were found to have been 
penetrated by larve which had emerged from the unseasoned 
wood of the ammunition-boxes. The same authority tells of the 
boring of the larve of S. gigas from the timber supports into 
the lead chambers of sulphuric acid works, with a loss of acid. 
PREVENTION AND REMEDY. 
Remove attacked sickly trees, and so prevent spread and 
infection. It is wise, too, to cover over any wounds and barked 
spots, otherwise suitable places for oviposition, with some mixture 
which would deter the insect from egg-laying. 
Mr Mitchell of Dunraven, Glamorgan, has taken up enthusi- 
astically inquiry into what species of injurious insects may be 
conveyed to South Wales in driftwood. Might I cordially 
recommend this research to foresters in other parts of the 
country well situated for the purpose, as a work of much scientific 
interest, but also for its possibilities on the practical side. In 
the history of insects all over the world, many of the most injurious 
forms in a country have often not been native, but have been 
introduced. Twenty years ago a French entomologist introduced 
into New England, United States, for purposes of experiment, a 
few specimens of the Gipsy Moth (Liparis dispar). A few escaped 
from confinement, and in spite of warnings issued, this insect has 
so multiplied that its polyphagous caterpillars have stripped the 
leafage of the trees of half a State, and necessitated the spending 
of some hundreds of thousands of dollars on exterminative 
