878 I'ROCEEDlNl^S fIF THE TIIIUD EXTOilOLOtMCAL MEETING 



are unsuitable and we use brass plates with a large hole in the middle, 

 the hole being protected with fine brass wire gauze soldered on to the 

 plate (see figure). In these cages the moisture can be regulated almost 

 to perfection by the use of these perforated brass covers, the holes in them 

 being left, when necessary, either entirely open or partly covered by glass 

 or brass sheets placed on the toi3. As a result we have hardly any 

 trouble from mould in the rearing cages. For those insects which pupate 

 underground, such as Noctuid larvee, a layer of moist earth is provided 

 at the bottom of the cage and they can without further attention go into 

 the earth and pupate there. The earth keeps moist for very long periods. 

 Therefore it is not necessary to disturb the insects at all. 



The glass dishes and jars are used as small aquaria for insects which 

 feed on aquatic leaves, for example, Nonagria pallida and Nymphula 

 whose caterpillars feed on floating leaves of Nelunibmm, or Galerucella 

 singhara feeding on floating leaves of Trapa. When used as aquaria 

 the cages are covered with muslin. For larger aquaria we use glass 

 troughs shown in figiu-e 2, on Plate 131. 



There are some insects which can be included among the leaf eaters 

 but which live underground as a rule, only coming up, usually at night, 

 to collect food, such as caterpillars of Agrotis and nymphs of the Large 

 Brown Cricket [Bracliijtrypes portentosvs). For them the glass jars are 

 filled with moist earth and leaves or cut plants placed on the surface of 

 the earth. 



There is another class of insects which form silken tubes underground, 

 the tubes serving as galleries in which they live. For them also the glass 

 jars and troughs are used with success. The caterpillars of Ancylolomia 

 chrysographella not only require earth to form galleries but also living 

 plants, rice or grasses, on the leaves of which they feed. The caterpOlars 

 of Melasma, Laiiioria. Mynnecozela., Machwropteris and others require 

 earth in which they can form galleries and are fed with leaves and grasses 

 placed on the surface of the earth. 



Zinc Cages. Grasshoppers have been reared successfully in these 

 glass jars. But on account of their saltatorial habits they are somewhat 

 cramped for space in these cages. They are best placed on potted plants 

 in the large zinc breeding cages illustrated in PI. 133. fig. 1. These cages 

 measure 24 inches in height and 12 inches across each side and are 

 provided with a hinged door. The door and the wall opjjosite to it 

 are of wire gauze with about 16 meshes to the inch. The other two 

 walls are of glass. The entire framework and the roof and floor are 

 made out of galvanized iron sheet. We also use simOar cages of a 

 smaller size measuring 12 inches in height about 8 inches across each 



