THE MICROSCOPE AND INSECT LIFE 



various flies worth examination also those of bees 

 on account of the clever device for uniting the front 

 and hind wings during flight. On the front edge of 

 the hind wings the microscope will show us a row 

 of minute hooks. When the bee makes a flight, it 

 hooks its hind wings to a ridge on the hinder edge 

 of the fore wings, so that for flying purposes it has, 

 to all intents, two wings instead of four. 



Having examined all the wings we can find for 

 the time being, we may turn our attention to 

 mouths. The mouth parts of insects are not only 

 interesting but important ; one of the first things an 

 economic entomologist does with a new specimen is 

 to examine its mouth parts. The mouth will tell 

 us what manner of feeder its owner may be. Some 

 insects have sucking mouths, and they must feed 

 perforce on liquids ; others have biting mouths, and 

 they are likely to do damage to crops by eating 

 them. Then there are lancet-like mouths and 

 mouths which are a compromise between biting and 

 sucking ones. The subject, however, is somewhat 

 complicated, and entails a knowledge of insect 

 anatomy, so we will merely deal with a few easily 

 understood examples. Our butterfly has a sucking 

 mouth; it is known as a proboscis, and may be 

 found, coiled like a watch spring, beneath its head. 

 There is no trace of anything in this mouth capable 

 of biting or even piercing the most delicate struc- 

 ture. The house-fly is also possessed of a proboscis 

 though of different design. Though a dangerous, 

 disease-carrying insect, it can do no harm with its 



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