(1IPSY MOTH AND BROWN-TAIL MOTH. 9 



wilt disease, however, which possibly may have occurred in this 

 countrv for many years, has become sufficiently prevalent to be a 

 prominent factor in natural control. 



INTRODUCED PARASITES AND ENEMIES. 



Iii 1905 an effort wa* made by the State of Massachusetts, in coop- 

 eration with the Bureau of Entomology, United States Department 

 of Agriculture, to introduce the parasites and natural enemies of the 

 gipsy moth from its native home in Europe and Japan. Since that 

 tune a large amount of parasitized material has been received and 

 as a result several natural enemies have become firmly established 

 in this country and are assisting in bringing about the control of 

 the species. The enemies which have become established and are 

 at present destroying the largest number of gipsy-moth caterpillars 

 and pupae are a beetle, 1 a tachinid fly, 2 which is also a parasite of 

 the brown-tail moth and attacks many native injurious caterpillars; 

 and a minute four-winged wasplike parasite, 3 which attacks small 

 gipsy-moth and small brown-tail moth caterpillars. Two tiny para- 

 sites of the eggs, one of which 4 was imported from Japan and the 

 other 5 secured from Europe, have also been colonized in a portion 

 of the infested area and are valuable additions to the natural enemies 

 of this insect. Several other parasites have been introduced and 

 are established in this country, but they have not increased suffi- 

 ciently to be classed as important factors in gipsy-moth control. 



The work of the natural enemies of the gipsy moth, including the 

 imported parasites, the Calosoma beetle, and the wilt disease, has 

 served greatly to reduce the numbers of the insect in many badly 

 infested localities. This is particularly true in the region which 

 has been infested longest, and it is hoped that when these enemies 

 of the moth have become established in larger numbers over the 

 entire infested territory the insect will be much less a destructive 

 factor than it is at present. Colonization of most of these species 

 has been carried on throughout the entire area but much remains to 

 be done in colonizing the egg parasites. The records at the gipsy 

 moth laboratory at Melrose Highlands, Mass., indicate that all of the 

 species of insect parasites mentioned have been gradually increasing 

 in the field during the past few years and the results of their work 

 are very noticeable in certain restricted areas. Until these natural 

 enemies become more abundant than they are at present throughout 

 the entire infested territory it will be necessary to employ the most 

 effective mechanical methods for restricting the spread and curtail- 

 ing the increase of this species. . 



1 Calosoma sycophanta L. s Apanteles lactricolor Vier. 5 Anastat.us bifasciatus Fonsc. 



1 Compsilura concinnata Meig. 4 Schedius Ituanae How. 



101329 Bull. 84^17 2 



