1911.] PUBLIC DOCUMENT — No. 31. 79 



should be continued for several years, if averages of value are 

 to be obtained. 



Nearly ten years ago a study of the Marguerite fly, a pest 

 too familiar to many florists, was begun, but was soon dropped 

 for lack of material. More having been obtained, this investi- 

 gation has been resumed, and it is hoped that the entire life 

 history of the fly may now bo learned, together with effective 

 methods for its control. 



Observations on the distribution limits of insect pests in 

 Massachusetts have been continued as opportunity has offered, 

 and some interesting facts on this subject have been obtained. 

 Work of this kind must, from its very nature, be fragmentary 

 for a long time, and for years the gathering and preservation 

 of the observations made are all which it will be possible to 

 accomplish. As the time required for this is but a few mo- 

 ments i:)er week, or even per month, however, the results are 

 well worth the trouble. 



Investigations on the importance of the Sphecidse as para- 

 sites have been continued, and a number of additions to our 

 knowledge of the group have resulted. The subject is a large 

 one, however, and the amount of time available for this pur- 

 pose has been much less than could be desired. Experiments 

 with insecticides have been almost at a standstill from their 

 entomological side, waiting for pure materials of known compo- 

 sition to be provided by the chemical department. Some of 

 these have been satisfactorily obtained during the fall and the 

 tests of them can be begun in the spring of 1911. The chemical 

 results of this work will be reported upon by that department. 



