138 Insect Architecture. 



pillar, which continues to grow, and seems to thrive, where- 

 as its bulk is largely made up of the ichneumon larvae. 



Microgaster glomeratus. 



[After the caterpillar ceases from feeding, it crawls aside 

 for the purpose of assuming the pupal state. But, before it 

 can do so, the ichneumon larvaB, which have also ceased 

 from feeding, burst their way through the sides of the cater- 

 pillar, and immediately begin to spin their cocoon. These 

 are oral, very small, and covered with yellow silk. A group 

 of these cocoons is shown at Fig. 3. The innumerable fibres 

 of these cocoons hamper the caterpillars so much that, in 

 most cases, it seldom is able to stir from the spot, but dies in 

 the midst of its enemies. Groups of these yellow cocoons 

 can be found in every wall or paling near cabbage gardens. 

 In a few days, the larvae have passed through their pupal 

 stage, assuming the winged state, and emerge from the cocoons 

 through little circular doors, as seen in Fig. 2. 



[Our second illustration represents another species, Micro- 

 gaster alveolarius, together with its cocoons. As before, the 

 insect is shown of its natural size at la, and magnified at 1. 

 The preliminary life of this insect is exactly the same as that 

 of the preceding ; but, instead of making a number of inde- 

 pendent and separate cocoons, the insects spin so closely to- 

 gether that they form an edifice very much resembling a bee- 

 comb. Fig. 5 represents one of these cell-groups of th 

 natural size, and the edge of another group is shown at Fig. 4 



