PEOCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 879 



side. When required for small parasites, etc., thin muslin or silk gauze 

 is gumme^ over the wire gauze. 



Zinc Cylinders. For Nymphtda deininctalis the glass jars proved too 

 small. The caterpillars require rice plants growing in water, so that 

 they can float and swim in water and crawl upon the plants. For them 

 the zinc cylinder illustrated in PI. 131, fig. 1 was used. These 

 cylinders are either with or without a bottom. Those with a bottom 

 can be used as aquaria. In the case of Nymphiila depunclalis 

 caterpillars, one with a bottom was used. Living rice plants were 

 transferred into it with a quantity of earth and it was partly filled 

 with water. A long stick, stood in the middle, supported the muslin 

 which formed the covering. The zinc cylinders without a bottom 

 can be pressed into the ground over living plants and when the 

 plants are low the wire gauze cover illustrated in figure 2 serves 

 the purpose well. For taller plants the covers shown in PI. 133, 

 fig. 2 are used. The cylinders are made out of thin galvanized 

 iron sheets and are 2 feet in diameter. All round the top on the outside 

 there is a channel about an inch in depth and breadth which can be filled 

 with kerosenized water to prevent access of ants or escape of creeping 

 insects. On the inside the top is provided with a sloping piece intended 

 to prevent escape of insects. This can, however, be done away 

 with. 



The cage illustrated in PI. 135, fig. 1 is made by pinning thin muslin 

 on a wooden frame. The bottom is made of wooden board. The door 

 is on one side and is fitted with a long muslin sleeve. This is a very 

 useful cage and serves many purposes better than the zinc breeding cages. 

 Moths and flies kept in it do not dash against hard surfaces as in cages 

 having glass or wire gauze sides in their flight or attempts at escape. 

 Therefore in such cases the risk of injury to them is very small. Also 

 the sleeved door is more advantageous than the hinged door of zLnc 

 cages. There is hardly any possibility of insects escaping through it 

 during manipulation. 



Having provided ourselves with the principal apparatus required, 

 we can now proceed to consider the various groups into which insects 

 may be classified according to their feeding habits and hence according 

 to the manner in which it is necessary to rear them. In this way insects 

 may be classified as : — 



(1) Scavengers of dead — • 



(a) animal matter, 

 (6) vegetable matter. 



(2) Predators on otljer animals. 



VOL. Ill E 



