12 NEW YORK STATE MUSEUM 



INJURIOUS INSECTS 

 Typhoid or house fly 



Musca domestica Linn. 



An attempt was made the past season to obtain accurate data re- 

 specting this insect's behavior toward Hght. The principal object 

 of the experiment was to determine the possibiHty of storing manure 

 and other substances in which this pest breeds, in dark or nearly 

 dark cellars or compartments. 



Outline of conditions. A fly vivarium [pi. i] was located in 

 the writer's back yard (a typical village lot) at Nassau, Rensselaer 

 CO., N. Y. This building was a nearly light-proof structure 6 feet 

 by lo feet in outside dimensions and with a hight of 6 feet 4 inches 

 in front and 5 feet 6 inches in the back. To facilitate the location 

 of materials etc., the spaces between the joists were numbered con- 

 secutively, beginning at the door on the north wall and running 

 around and including in the ■enumeration the spaces of the parti- 

 tions as well as the outside wall [see pi. 2]. A light-proof window 

 (18 X 18 in.) was made in the south wall near the southwest 

 comer (at station 16) and another in the west wall (at station 13). 

 Light-proof partitions, arranged somewhat like those in a photog- 

 rapher's dark room divided the interior [see pi. 2] in such a manner 

 that there was a constant decrease in the light as one progressed 

 from the door back through the partitions and around to the darkest 

 corner near the middle of the south end, station 12. Ventilators 

 were provided in the roof at A and B [see pi. 2]. There is in 

 the southeast corner at station 23, a small closet 21 inches deep 

 and 3 feet above the ground. The interior of the building was 

 painted a dull black the latter part of April. The door located at 

 the northwest corner is 26^ inches wide and 71^ inches high. 

 This door was allowed to remain open throughout the season and 

 the entrance of animals or children prevented by the use of a 

 coarsely screened (^ inch mesh) door having an interior clear 

 space of 23 by 6y inches. The building was so situated that August 

 24 at 8 a. m. rays of the sun reached back to the base of the 

 corner of station 8 and a little later in the day would extend to the 

 base of the pail at station 6. There was sufficient illumination 

 under these conditions at station 18 so that one experienced little 

 difficulty in discerning objects located there. Mackerel kits con- 

 taining horse manure thoroughly sterilized by steam were located 

 at stations 6, 12, 18 and 23. In addition, sheets of a dull black 

 paper, specially treated through the courtesy of the O. & W. Thum 



