REPORT OF THE SOCIETY 13 



Conditions of successful rearing of Insects. — In general, success in 

 rearing insects demands experience in selecting those conditions of existence that 

 will permit the insect to make a normal development. It is very easy to place 

 an insect in abnormal conditions, consequently the investigator must have a fair 

 knowledge of its habits in all stages in its normal environment before he attempts 

 to rear it under a more or less artificial environment-. 



The important factors in successful rearing are stated by A.M. Wilcox 

 (Psyche, Feb. 1917) as follows: — ■ 



1. An abundance of normal food. 



2. A suitable environment for the different stages. 



3. The regulation of temperature and humidity. 



4. The prevention of disease. 



5. The prevention of parasitism. 



The most experienced rearers are often disappointed at times, but the results 

 can usually be traced to neglect in taking proper precautions at some stage. 

 Failure occurs most often with regard to the regulation of temperature and humi- 

 dity, for these factors also play an important part in attacks of disease. Eggs, 

 larvae, and pupae are influenced detrimentally either by too little or too much 

 moisture, besides moulds are very apt to develop under conditions of excessive 

 humidity. 



The general rule is to make conditions as near the natural as possible, but of 

 course we all know how conditions in nature may sometimes be abnormal, if we 

 may judge by the large percentage of deaths that occur some seasons. A better 

 rule would be to make the conditions natural without the introduction of the 

 lethal factors that sometimes operate in nature. 



Simple Cages — All kinds of devices for rearing insects and observing their 

 work — from simple and easily constructed types, to elaborate insectaries — have 

 been in operation for many years. The simpler types range from shell vials, tin 

 salve-boxes, tumblers, lamp-chimney-flower- pots to cages of various forms, depend- 

 ing on the kinds of insects under investigation. Several workers find shell vials very 

 convenient in rearing many forms of insects, even large caterpillars. One larva 

 is placed in a vial along with a piece of its food plant which is renewed every day, 

 and the vial plugged with cotton wool. When large numbers are being handled, 

 the vials may be arranged in flat trays even three tiers deep, so that they can be 

 examined readily and at the same time occupy a small space (Figs. 1 and 2). 



The lamp-chimney or lantern-globe cage has long been in use by students of 

 Entomology (Figs. 3 and 4). It may be placed over a plant growing either in 

 soil in a flower pot or in a large vial of water and upon which insects are feeding. 

 Cuttings of plants can be kept fresh for a long time when placed in a small vessel of 



