BUREAU OF ENTOMOLOGY. 263 



fiuit flies and other tropical and subtropical fruit insects arc now 

 established in tlie zone, and to the further fact that the zone is more 

 or less of a world's crossroads, i; e., a place where insect pests from 

 remote places may be carried through the agency of conunerce and 

 easily gain lodgment, later, perhaps, to effect entry into the main- 

 land cultures, tropicid and subtropical, of the United States. This 

 work, now in progress for one year, has developed useful informa- 

 tion. Mucli work has been done in connection with the so-called 

 black fly of citrus and other plants, which has become established in 

 the Canal Zone and in the West Indies, and which a very determined 

 effort is being made to exclude from the southern United States. A 

 considerable number of other important injurious insects have al- 

 ready been discovered and have been the subject of studies. Among 

 these are no less than four different kinds of fruit flies. There have 

 been foimd in the Canal Zone also a number of insects which very 

 injuriously affect commercial woods and wood structures. Termites 

 are very important subtropical insects found in the Canal Zone. 

 Seveial of these are abundant in the State of Panama and several 

 have been found in the Canal Zone, some of which are very destruc- 

 tive to garden crops. The entrance cf some of these into the United 

 States would be followed by great injuries. The number of subjects 

 whicli have been investigated at this station is already enormous, 

 and a very convincing sliowing has been made of the need of keeping 

 constantly in touch with the plant cultures and insect enemies in this 

 district as a means of beneflting local production, but pailicularly as 

 furnishing information on which any necessary protective action in 

 the interests of the United States may be taken. 



WORK ON THE GIPSY MOTH AND BROWN-TAIL MOTH. 



This work has been continued under the supervision of Mr. A. F. 

 Burgess, with headquarters at Melrose Highlands, Mass. 



For the first time since the bureau began work to prevent tha 

 spread of these insects, it is possible to report a substantial decrease 

 in the infested territory. This amounts to 1,824 square miles pre- 

 viously infested with the gipsy moth and 5,885 square miles by the 

 brown-tail moth. Twent3'-eight towns in New Hampshire, 6 in Ver- 

 mont. 8 in Massachusetts, and 10 in Connecticut, 52 towns in all, 

 were found to l>e free from gipsy moth infestation and were elimi- 

 nated from the quarantine area this year. There is now under 

 quarantine on account of the infestation by the gipsy moth 20,747 

 square miles in New England. Isolated colonies of the gipsy moth, 

 which were found in pixivious years in New York, Ohio, New" Jersey, 

 and the western part of Massachusetts, have again been carefully 

 examined but no infestation found. There seems to be no reason- 

 able doubt that the insect has been exterminated in these colonies. 



The decrease in area infested with the brown-tail moth includes 

 84 towns in Maine, 58 in New Hampshire, 6 in Vermont, 87 in 

 Massachusetts, and 10 in Connecticut, a total of 145, embracing an 

 area of 5,885 square miles which was released from quarantine this 

 year. There are now quarantined on account of this insect 28,752 

 square miles. 



