145 



tire patch at once, the cost would probably be greater thau that of some 

 other remedies, but this might be more than compensated for in this 

 case by effectiveness, since we are all aware of the difficulties of apply- 

 ing liquid remedies for this pest. With potato bugs, however, it is ex- 

 tremely doubtful whether any disease could be artificially introduced 

 which would begin to compare with the arsenical applications when cost 

 and efficiency are taken into consideration. To sum uj), I think we are 

 justified in the following inferences : 



First. That there are diseases amply sufficient as a basis for economic 

 work, the bacterial forms giving the most promise for all cases where 

 early results are desired, while those due to fungi, so far as present 

 knowledge goes, propagating slowly, can only be used as slow but 

 efficient checks to injurious forms, the most we can do with them being 

 to introduce tbem in localities where not already found. 



Second. That the diseases can be controlled to the extent of preserv- 

 ing the germs for a season and transporting them from place to place 

 to use for inoculation, but that its spread in nature will be affected by 

 conditions beyond our control, while only such insects as occur gregari- 

 ously or live in mingled hosts can be attacked to advantage. 



Third. That the cost of application would prevent its adoption ex- 

 cept in certain forms. 



Finally, we must consider this method of contending with insects at 

 best as but one of a number of profitable methods to be Uised in certain 

 cases where other methods are insufficient and to supplement other 

 methods where it can be done to advantage. With this end in view 

 the diseases of insects are worthy of the most careful study, and will 

 not, I think, disappoint us in their final results. 



A NEW AND REMARKABLE ENCYRTID: IS IT PARASITIC? 



By L. O. Howard, 



In September, 1890, Dr. J. N^. Rose, of the Botanical Division of this 

 Department, brought to the Division some herbarium specimens of the 

 twigs and flowers of Courseiia {?) mexicana, Watson, a rare leguminous 

 tree collected in the Alamos Mountains of Mexico early in 1890, by 

 Dr. Edward Palmer. The plant was in full bloom, and fully half of 

 the flowers had the petals pierced with a small round hole opposite the 

 stalked ovary. The hole extended through into the ovary, which was 

 abnormally swollen, and which was found to contain in many instances 

 a perfect adult of a very abnormal Chalcidid just ready to emerge. 

 Other unperforated flowers were examined, and in similar swollen 

 ovaries the same insect in an advanced pupa state was found. Out of 

 over fifty flowers which I examined I was unable to find one which was 

 not infested in this peculiar way, and in one case the base of the pistil 

 12746— No. 4 2 



