1916 ENTOMOLOGICAL SOCIETY. 135 



HlBEENATION OF THE AdULT. 



As has just been seen a certain number of the flies that emerge as adults in 

 the autumn live as long as twenty-five days, this period being passed in a six-inch 

 vial. It was thought possible that the stage might be prolonged still more if the flies 

 were allowed more room for flight and if this occurred we might persuade some of 

 the flies to pass the winter in the adult condition. Accordingly a large 

 cage was arranged consisting of wire mesh and suspended within was a large piece of 

 rough fir bark, with many crevices into which flies might crawl should they 

 desire to. This cage was suspended to the outside wall of the building. A small 

 amount of sweetened water was placed on the floor of the cage, upon which, later, 

 it was observed, the flies fed readily. No cabbago plant was introduced into the 

 cage for fear the flies would be tempted to deposit eggs, and if they did so, their 

 life functions would be over and they would probably die. Into this cage twenty- 

 two flies of both sexes were liberated between September 22nd and 27th. Exam- 

 ination of the cage was difficult for fear of allowing the flies to escape. However, 

 flies were observed dead on the floor of the cage on September 25th and finally on 

 October 8th all the flies had died. On October 5th only six flies were observed 

 dead on the floor of the cage, hence a rapid mortality must have occurred between 

 the 6th and the 7th. The night of the 7th was the coldest night thus far exper- 

 ienced during the autumn, being 33 degrees F. This temperature may have killed 

 the adults. At any rate we have nothing to offer which proves that flies winter 

 over as adults although indications that such might occur were propitious. It 

 might be noted again that no flies emerged from puparia after September 27th, 

 despite the fact that 193 puparia were still confined on soil in boxes on that date. 



I can only say that the number of flies experimented with in this instance was 

 far too small to record an invariable and establishecl fact I can merely say that 

 those flies used did not survive the flrst touch of cold weather and hence did not 

 pass the winter as adults. It might, however, be said with reason that it is highly 

 probable that a small percentage of adults will winter as adults in a favorable 

 season, although such has not been shown in our experiments thus far. 



Egg Deposition in Field. 



Not only do adult flies emerge freely from the puparia during September and 

 probably part of October, but we find also that eggs are deposited equally freely 

 during these months. These notes, recorded now, are a part of a long series of 

 notes obtained throughout the summer on the question of egg deposition hence I 

 shall not give the full details at this juncture. We are only interested now in the 

 autumn development. To obtain this record 12 cabbages' and 6 cauliflowers were 

 examined daily between 4 p.m. and 6 p.m. and all eggs laid during the twenty-four 

 hours removed by means <k a knife blade and counted. By this method we would 

 obtain an absolutely accurate record of the daily deposition. Further useful in- 

 formation may be deduced in reference to effects of temperature, sunshine, rain, 

 wind, on egg deposition and the size and shape of the plant chosen for deposition. 

 The record follows in table 3. (For the sake of comparison the record of 

 12 oabbages is reduced to read for 6.) 



