268 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



of this tray has been used with excellent results for rearing larvi'e in 

 large numbers. This form is 5 feet long, 2 feet wide, and 4 inches 

 high. Approximately 300 trays of these two sizes have been in use 

 this season and the results have been entirely satisfactory. The ad- 

 vantages of this device over the ordinary Riley cage are very pro- 

 nounced. Any one who has used the latter for rearing large quan- 

 tities of larva? has been confronted with the difficult problem of feed- 

 ing the caterpillars without allowing them to escape. It is impossible 

 in one of these cages to secure reliable data on feeding habits of the 

 insects. Avhich are being reared, and information concerning the habits 

 of their parasitic enemies cannot be readily obtained because of the 

 small area contained in the cage and also on account of the inability 

 of an observer to watch the oviposition of parasites on their larval 

 hosts. The Fiske tray overcomes practically all of these difficulties. 

 The caterpillars are made to feed in such a way that they are exposed 

 to the view of the observer, the Tanglefoot band preventing them from 

 escaping from the tray. In case it is desired to make observations on 

 the oviposition or habits of parasitic insects which attack the caterpil- 

 lars, these trays can be placed in a tightly screened room or house 

 in which the parasites may be liberated and where the observer can 

 have ample opportunity to observe their operations. 



For the purpose of rearing some insects, such as beetles which spend 

 a part of their life in the ground, it is usually desirable to use glass 

 jars partially filled with earth. We have in the past used cheese- 

 cloth covers. Avhieh Avere held in place by rubber bands or string. 

 Both of these methods of fastening are objectionable, the former on 

 account of the continual breaking of the bands and the latter because 

 of the annoyance in untying the string to remove the cover. Some in- 

 sects are able to cut through the cheesecloth and make their escape 

 and this has often caused the loss of specimens from which valuable 

 data was being secured. This year we have used a circular, wooden 

 cover made of one inch planed pine. (See PI. 4, Fig. 3.) A groove 

 was turned one half inch from the outer edge of the cover and of 

 sufficient width to admit the upper edge of the jar. A 2-ineh hole 

 was then cut or bored in the center, the under side of which was cov- 

 ered Avith wire mosquito netting. This furnishes a cover which can 

 be easil}^ removed and replaced and is tight enough to prevent the 

 escape of insects which are being reared. The wire netting in the 

 top furnishes sufficient air supply to prevent condensation of moisture 

 on the inside of the jar. 



Another cage which has been successfully used this season for rear- 

 ing Calosoma larva? is illustrated in PL 4, Fig. 4. It is 10 inches in 



