182 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



it better to carry out much experimental and otiier work in various 

 cages erected in the open. If we wanted normal soil conditions we 

 could get them only by the use of soil cages outside of the insectary. 

 For other work tree cages or ground cages of various kinds, with or 

 without a weather-proof top, and erected on normal soil, have proved 

 not only better but necessary. It is our belief now that no permanent 

 insectary can supply this need. 



In winter we have come to consider that the storage of hibernating 

 material can be accomplished easily and satisfactorily without making 

 use of a dismantled insectary. Such material can easily be maintained 

 under thoroughly normal conditions in temporary shelters, or on the 

 ground under the protection of wire screening, or in the soil, or else- 

 where, as the case may be. 



In our rather severe climate it has been found that the dismantled 

 part of the insectary tends to fill with ice and snow in winter. This is 

 apt to be destructive of concrete. 



Finally, there is no opportunity for winter work with living insects 

 or plants. 



In the light of the above experience changes have now been made 

 in the insectary as follows : 



We have retained the closed room entire, the foundations, bins, 

 etc., of the open room, the removable frame work as far as the eaves, 

 and the removable screen sides. In place of the double canvas roof, 

 we have substituted a regular greenhouse roof, permanently set with 

 glass. Glass sash, put on with screws, take the place of the wire screen 

 sides in winter. Steam heat is provided in the former open work- 

 room during the cold season, which, with us, lasts five or six months. 

 No steam pipes run into the small, enclosed room, which can be kept 

 cold, cool or warm by opening or closing the door to the larger room 

 and by the use of ventilators. 



The cost of these changes, complete, was about $250. This in- 

 cluded $115 for steam pipes, asbestos covering, steam trap, and the 

 labor charge for running an underground main from a near-by building. 

 The new glass roof and sides cost $95. The carpenter's bill was $40. 



The present plan, therefore, is to transform the insectary into a 

 greenhouse through late fall, winter and early spring or as much of that 

 as seems desirable. In summer the glass sides will be removed, the 

 screen sides substituted, the roof will be coated thickly with whiting 

 and if this does not provide normal temperature a canvas roof will be 

 added above the glass roof with an air space between. 



By this means it is our idea to retain the usefulness of the structure 

 for summer work as in the past, and to add to this an equivalent use- 

 fulness through the winter season, which has not heretofore been true. 



