REPORT OF THE STATE ENTOMOLOGIST I909 Q 



Chester though not very evident on account of the large amount 

 of provender upon which they could subsist. 



House fly. This insect, with its acknowledged potentiality 

 for evil, is one of the most important of our injurious species. 

 The present great interest in the house fly and methods for its con- 

 trol led to the devising of a vivarium or special house for the 

 purpose of testing the behavior of this insect in relation to light 

 and in particular to ascertain whether darkness or partial darkness 

 could not be used as a barrier to keep this ubiquitous form from 

 breeding materials of various kinds. The house was a light-proof 

 structure with partitions arranged in about the same way as those 

 in the photographer's dark room, and flies were given a free oppor- 

 tunity to enter as far as they would with a constantly decreasing 

 illumination and deposit eggs upon moist horse manure. The de- 

 tails of the experiments, given on a following page, show that this 

 insect will not invade moderately dark places for the purpose of 

 depositing its eggs. It should be comparatively easy and very 

 practical to store all such materials in dark or nearly dark places. 



Gall midges. The work upon this group has been pushed as 

 rapidly as possible consistent with the discharge of other duties. 

 We have been able to make material additions to our knowledge 

 of the biology of this group. This was particularly marked in the 

 case of Sackenomyia, originally described from a female taken on 

 the wing and now represented in addition by two reared species, 

 of which both sexes, larvae and galls are known. The life histories 

 of a number of species of Caryomyia, forms responsible for the 

 peculiar and varied hickory leaf midge galls, have been worked out. 

 Likewise, a number of species of Cincticornia, a genus confined 

 to oak, have been reared and some exceedingly gratifying data 

 obtained. This by no means exhausts possibilities with this group, 

 since material has come in so rapidly in recent months that it has 

 been practically impossible to classify it adequately and at the same 

 time collect or rear additional forms. Over 50 species have been 

 reared during the year, most of them new and making a total in 

 the collections of probably over 800 species, about 350 having been 

 reared. This large number of specimens, in some instances species 

 are represented by a hundred midges, is practically classified and 

 requires only a relatively small amount of descriptive and coUative 

 work before being made available to the public. 



Special acknowledgments in this connection are due Miss Cora 

 H. Clarke of Boston, Mass. who has collected and forwarded to 



