134 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
every one of which is a favored host plant in other regions, but not a 
single brown-tail nest was seen and, according to M. Dillon, it was 
never found upon these trees. Farther on an elevated plain was 
passed, with occasional ridges of uncultivated land upon which were 
growths of a deciduous scrub oak. Gipsy-moth eggs, pupal shells, 
etc., could usually be found by a little search under the stones on these 
ridges, but the brown-tail moth was conspicuous by. its total absence. 
The next day the route selected passed through an extensive forest 
of cork oak, mingled with pine, and finally up the sides of the moun- 
tain, until great plantations of aged chestnut trees were indicative of a 
change in climatic conditions brought about by the considerable alti- 
tude. Various shrubs and a few trees unknown or rare in the lower 
elevations became a feature of the forest, and among them the arbusier 
(Arbutus sp.), closely resembling in its growth, in the appearance of its 
evergreen foliage, and in its habitat the mountain laurel of our own 
southern mountains. It is very beautiful and unusual in its appear- 
ance, partly on account of its flowers (which are suggestive of Oxy- 
dendron) but more particularly because of its fruit. This was globu- 
lar, about the size of a marble, and hung pendant on long stems in 
more or less profusion, and in all stages of ripening. In the course of 
this process it passed from green through a sequence of vivid yellows 
to orange, and finally intense scarlet. It was at once recognized as 
the host plant of the hundreds of nests which had been collected and 
shipped by M. Dillon. Although it was occasionally met with suffi- 
ciently far down the mountain side to mingle with orchards and 
hawthorn hedges, ‘according to M. Dillon the brown-tail moth invari- 
ably seeks it out, even there. The selection of a food plant repre- 
senting a totally different order from any selected in other parts of 
Europe or in America, and this in spite of the fact that what are 
ordinarily its most favored hosts were frequently much the more 
abundant, was considered to be quite as remarkable as the assump- 
tion of terrestrial habits by the gipsy moth.* 
In central and western Europe generally the brown-tail moth finds 
a stronghold in the dense Crategus hedges which are commonly 
planted in many localities, and upon them as well as upon oak and 
fruit trees it is frequently abundant. In these regions, also, not only 
the food plants, but the seasonal and feeding habits are quite like 
those in New England. Occasionally an apple tree or an oak will be 
found carrying an abundance of nests and, as noted by the senior 
author in northwestern France in 1909, the moths are sometimes so 
1 Tt has since been learned that in the warmer parts of the region visited, the brown-tail moth caterpillars 
not only remain active but feed to some extent during the winter. In the middle of January, 1911, the 
nests were found commonly, always upon Arbutus, in parts of the coast regions near Hyéres, and in nearly 
every instance the caterpillars were active and in most they were feeding. In this particular locality the 
nests were very different from those typical of the caterpillars in northern localities, being loosely woven, 
and not at all designed for hibernation in its stricter sense. 
