888 
Miarvels 
A PARASITE OF THE HORN-TAILED WASP. 
By some strange instinct this Ichneumon can discover the 
borings of the Horn-tails and therein lays its eggs, from which 
On the 
left is a piece of wood in which an ovipositor of a Horn-tail 
the young hatch out and devour the Horn-tail grubs. 
was found fixed. 
period in the winter. 
of the Universe 
vapours of the horizon. Thus, notwithstand- 
ing that the sun is then continuously visible, 
on account of its low altitude the amount 
of heat is not excessive ; whilst, on the other 
hand, its complete absence during several 
weeks of winter partly accounts for the severity 
of the climate within the Arctic (and Antarctic) 
zones ; for perpetual day in summer has its 
correlative of perpetual night in winter. At 
either pole the sun is above the horizon for six 
months at a time, being below the circle for 
the rest of the year, circling round the sky 
almost parallel to the horizon (“ parallel 
sphere ’’), its altitude varying with extreme 
slowness, but never (on midsummer day for 
each hemisphere respectively) exceeding 234°. 
All places from latitude 663° N. to the 
pole have perpetual day for a shorter or 
longer period, between March 21 and Sep- 
tember 23, those not far within the Arctic 
Circle for a few days in June only; whilst 
perpetual night reigns for a corresponding 
In the southern hemisphere (Antarctic zone) the phenomena are exactly 
reversed ; perpetual day occurs sometime between September 23 and March 21, perpetual 
night sometime between March 21 and September 23. 
THE TUNNELS OF THE HORN-TAILED WASP’S GRUB. 
The grub of the Horn-tail will complete the task commenced 
by the mother and will bore a tunnel of considerable length. 
When fully grown it spins a cocoon, weaving into it the chips of 
the gnawed wood. These grubs work havoc amongst the trees 
they favour. 
THE HORN-TAIL WASP 
BY EDWARD STEP, F.L.S. 
THE Horn-tail, though called a wasp for con- 
venience, is more nearly akin to the saw- 
flies whose grubs reduce the foliage of goose- 
berry-bushes and other plants to hideous 
But the Horn-tail, though in size 
and appearance much mor formidable, is a 
skeletons. 
solitary insect that is rarely seen, and its 
grub carries on its depredations out of sight 
in the timber of growing pine-trees. There 
are cases on record in which whole plantations 
of coniferous trees have been rendered worth- 
less as timber owing to their being so riddled 
with the burrows of this grub. 
The size and appearance of the perfect 
insect may be gathered from our photographs, 
The larger of 
the two has its body banded with orange and 
black, and its body ends behind in the stout 
horn-tail. 
The “horn-tail” is really a beautifully- 
contrived auger within its sheath, by means 
which represent two species. 
