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FAMILY TACHINIDJE. 



These flies parasitise caterpillars, the larvae of 

 saw flies, and young grasshoppers. They are sim- 

 ilar to, but can be distinguished from house flies by 

 the bare bristle of the antennas, for it is feathered in 

 the house fly. 



We kept a very large caterpillar of the case moth 

 {Mctitra elongata) in a cardboard box with a glass 

 front, putting in a dish with moist sand and a 

 sprig of the cypress-tree on which it was feeding; 

 the latter was placed in the moist sand. For two 

 months the caterpillar lived on, walking round the 

 box, and seemingly quite content. One morning 

 we observed dozens of queer-looking creatures 

 scattered over the glass - front of the box. 

 They were tachinid flies which had just emerged, 

 and their wings were not yet expanded and dried; 

 hence their curious appearance. At last their wings 

 were spread and nearly dry, when we placed them 

 in a net and then into the killing bottle to count 

 them. A few escaped, but we counted 127 flies, all 

 of which were bred out of the one unfortunate 

 caterpillar. The mother tachinid lay her eggs on 

 the caterpillar; they are very tiny, and they are 

 made secure by a sticky fluid which then dries and 

 Axes the eggs firmly on to the host. The maggots 

 then make their way into the caterpillar and feed 

 on its tissues. The full-grown maggots then emerge 



