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. 1 



In central and western Europe generally the brown-tail moth finds 

 a stronghold in the dense Crataegus 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 



i It 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 Hyeres, 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. 



