SOUTH xiFRICAX CATERPILLARS 189 



a breeding cage, so that all moiills can be observed and 

 the various instars studied. 



Various types of breeding cages have been devised and 

 may be obtained from dealers in entomological supplies. 

 But breeding cages which ^^'ill suit the majority of our 

 breeding experimeats can be made quite easily by the 

 collector himself with very little trouble and expense. 

 For caterpillars requiring special conditions, such as 

 root-feeders or other underground species, special cages 

 have to be made. But for the majority of the cater- 

 pillars subsisting on leaves, fruits, wood, seeds, etc., the 

 cage need not be elaborate. The important point to be 

 kept in mind is that the new surroundings in which the 

 caterpillar finds itself should approach as nearly as 

 possible the natural conditions. This means that there 

 should be plenty of ventilation, light, fresh air, and — a 

 very important point — cleanliness. 



As regards ventilation, caterjiillars collected in the 

 field have been accustomed to an unlimited quantity of 

 fresh air and the change to the stuffy condition of a 

 closed breeding cage is apt to have a deleterious effect. 

 Therefore, the breeding cage should never be entirely 

 closed. Also, the moisture, given off by the food-plant 

 and the larva, would very soon make the atmosphere 

 much too damp and disease may follow. It is therefore 

 advisable to have at least two sides of the breeding cage 

 entirely or partly made of gauze to allow free passage 

 of air. Even for such caterpillars as feed in the interior 

 of their food this is the best plan to follow, for to those 

 which live in partly dried-up seed pods, wood, etc., a 

 gradual drying out of the material is a natural condition 

 and thus would not interfere with the normal develop- 

 ment of the larva. Glass jars or similar containers used 

 for breeding should have the top covered with cheese- 

 cloth or mosquito net. 



As to light: it is best to have the breeding cage so 

 constructed that there can be an abundance of light, 

 as the light in the room is always considerably less than 



