THE GIPSY MOTli AS A FOREST INSECT. 9 



exposure dried up without showing traces ot" the (h'coni])()sition 

 invariably associated with the ''wilt." 



As a result, iii the worst infested portions of the forest there would 

 be very few eggs, but the caterpillars would always be remarkably 

 healthy the next season, and as the parasites would be attracted to 

 the more badly infested parts of the forest the rate of increase else- 

 where would be simply astounding. 



In the Calabrian forest the invasion had not passed beyond its 

 preliminary stages in 1911, but by 1912 it had reached its maxi- 

 mum. Here conditions wxn-e the same, except that as the surround- 

 ing fields offered better protection from the glaring sun the cater- 

 pillars coming out of the forest lived longer and did more damage to 

 the crops. The trees in both forests were absolutely stripped of foliage 

 whenever there were sufficient caterpillars and not left, as they are 

 so commonly in America, where the disease is prevalent, with a 

 sprinkling of partly eaten leaves. All kinds seemed to suft'er alike. 

 There were no conifers except a few cypress (related to and witii 

 foliage very like our white cedar) which grew along an agave hedge, 

 bordering the Sicilian forest. These were strij^ped as bare as the oaks. 



In no locality other than these two, whether European or American, 

 has the writer been able to find the gipsy moth unaccompanied b}' 

 disease. It is the prevalence of such extraordinary conditions and 

 their similarity to those which ]) re vailed in America before the devel- 

 opment of the disease which serve to convince lum that the present 

 improved conditions are so largely due to tlie presence of the ''\vilt" 

 disease. 



FOREST CONDITIONS AS A FACTOR IN CONTROL. 



It is obvious, even to the casual American, traveler, that in most 

 European countries aj^plied forestry is developed to an unfamiliar 

 extent. The forests are treated mth an intelligent respect for their 

 reciuiremcnts and a careful consideration for their contmued w^ell- 

 bemg rarely apjiroached in America. It may even be said that they 

 are among the most stable of European institutions. Nations have 

 risen and fallen, but policies of forest management adopted half a 

 thousand years ago are used as a working l)asis in tliose same forests 

 to-day. 



This being the case, it logically follows that if the gipsy moth had 

 ever threatened the European forests to anything like the extent 

 that it threatens American forests to-day, methods of forest manag(^- 

 ment would have been evolved which, either consciously or uncon- 

 sciously, would have taken its destructive tendencies into consideia- 

 tion. After having studied the gil)sy moth in these forests both Mr. 

 Worthley and tlie writer are much inclined to the opmion that some- 

 thing very like this has taken })lacc. 



