124 THE ENTOMOLOGIST. 



interior. If it is now cut open the core will be found partly 

 hollow, the fruit fissured in various directions ; and, surrounded 

 by excrementitious matters and debris, from ten to thirty little 

 yellowish white maggots may be seen. The pears now fall off or 

 crack, when the larvae leave the fruit, which they seem especially 

 inclined to do in wet weather ; the rain either making the pears 

 crack or penetrating into the fissures, when the larvae creep out, 

 and, if the pears are still on the tree, spring to the ground, they 

 possessing, like other species of Diplosis, the power of skipping 

 or jumping. As soon as they reach the earth, they bury them- 

 selves, and after assuming the pupa- state remain hidden in the 

 ground until the following spring, when the imagines emerge to 

 renew their depredations. 



The ravages committed in orchards by the pear-midge, were 

 known in Germany and other parts of the continent of Europe 

 many j^ears ago, and the habits of the little pest were well 

 described by several naturalists. Schmidberger seems to have 

 been the first who accurately detailed its life-history, and his 

 account, copied from papers published in the ' Isis ' and other 

 periodicals between 1827 and 1837, was well given by Vincent 

 Kollar in his treatise upon injurious insects, published in Vienna 

 in 1837, and translated into English by Loudon, with notes by 

 Westwood, in 1810. Though the habits of this little insect were 

 well known, the scientific description of it was so imperfect, that 

 its name could not be accurately determined by entomologists. 

 The Cecidomyia nigra of Meigen was put down as the pear-midge 

 by Schmidberger, and his opinion has been generally followed, 

 though, as Professor Mik says,* " How Schmidberger could be 

 led to consider his Cecidomyia, bred from pears, as C. nigra, 

 Meig., I can only explain by its possession of a long ovipositor." 

 Nordlinger, in ' Die Kleinen Feinde,' in 1869, describes another 

 pear-midge by the name of Cecidomyia 'pyricola, but his account 

 is so poor that the species cannot be recognised, and his insect 

 and Schmidberger's are probably identical. To clear up the 

 matter and determine the genus and species of the pear-midge, it 

 became necessary to breed examples of the fly from larvae found 

 in the pears themselves ; and the credit of being the first to do this 

 is due to Dr. Riley, the celebrated American State Entomologist. 



* In the translation of a letter from him to Dr. Riley, published in the ' Report 

 of the Entomologist ' for the year 1885. 



