FIFTH REPORT OF THE DIRECTOR I908 



43 



Gall midges. The studies upon this important group have pro- 

 gressed very successfully. We have already prepared preliminary 

 keys for the separation of most forms into subfamilies, tribes, genera 

 and species, together with tables giving the food habits of those 

 which have been reared. Some idea of the magnitude of this work 

 may be gained when it is remembered that we have studied over 

 300 bred species and now recognize 700 species, representing about 

 50 genera. The systematic arrangement alone of this large num- 

 ber of microscopic insects is an immense task; in addition to die 

 above, many descriptions have been drafted and numerous biological 

 notes transcribed. 



The later work upon these insects has of necessity been confined 

 mostly to systematic study, owing to the fact that material was com- 

 ing in faster than it could be worked up in a satisfactory manner. 

 We have succeeded in rearing during the past season, in spite of 

 the pressure of other matters, about 75 species, the biology of most 

 of which was previously unknown. There is on hand a large series 

 of galls from which some extremely desirable material may be ex- 

 pected another season. The work upon this group is so well in hand 

 that there should be no difficulty in bringing it to a successful 

 conclusion in the near future. 



The rearing and care of breeding jars containing gall midges 

 requires much time. Assistant Entomologist D. B. Young had 

 general charge of this work and was ably assisted by Miss Fanny 

 T. Hartman. In addition, Mr Young rendered material service in 

 separating the large material into the major groups, while Miss 

 Hartman has made over 600 microscopic preparations. 



Flies and mcsquitos. The ubiquitous and well known house fly 

 has been the recipient of much attention because recent investiga- 

 tions show it may be the responsible agent, under certain condi- 

 tions, in the dissemination of typhoid fever and other grave intes- 

 tinal disorders. Observations upon its life history and habits have 

 established the practicability of largely reducing if not eliminating 

 this menace to health and personal comfort. A press bulletin on 

 this insect was issued and this will be supplemented by a more 

 extended account. 



There is much interest in the control of mosquitos. The Ento- 

 mologist inspected the work in progress on the Flushing meadows 

 and has kept in touch with similar operations in other localities. 

 Attention has also been given to the control of fresh-water species, 

 especially the malarial carrying form. The practicability of such 



