280 Couper on the destruction of Apple-trees 



out of the hole by which it has entered. When fully grown it 

 becomes a pupa, which like the door-bug, exhibits short folded 

 legs, wings and horns, of no use to it while within its burrow. 

 Early in June, the pupa-skin is ruptured, and the insect emerges 

 from the tree by gnawing through the thin covering of bark that 

 protects the upper extremity of the hole. Upon issuing into 

 the air it is found to be a beetle,* white beneath, and longitu- 

 dinally striped with brown above. In this, its perfect state, it lives 

 only upon the young and tender leaves of the apple and other 

 allied trees."— T. W. Harris, in iV. U. Farmer^ vol. 11. 1833. 



Fig. 1. Saperda Candida. Fig. 2, Larva of Same. 



The above is all that was known of this borer when Mr. Harris 

 wrote in 1833, yet his knowledge of the insect was suflScient to 

 cause the apple growers at that time to look out and prevent its- 

 extension. It is from carelessness and inattention that this insect 

 is now found in every apple-growing State in the Union. In 

 1825 an orchard in the neighbourhood of Troy was injured by 

 this Saperda to the extent of two thousand dollars. 



The Natural History of New York, vol. V., p. 120, states that 

 the Saperda Candida is three years in coming to maturity. I have 

 reason to doubt the length of metamorphosis here given by Mr. 

 Emmons, who is not considered an entomological authority — the 

 above book being full of errors. From my own observations, the 

 metamorphoses are gone through annually, that is to say, the 

 arva casts its skin periodically for 12 months, the insect appear- 

 ing in June, and the ova deposited in June. The fact of the beetle 

 being " more abundant some years than others," as stated by 



♦ Say, the American entomologist, described this insect as Saperda 

 bivittata, two longitudinal stripes running from the thorax to end of 

 elgtra. The Fabrician name is preferable on account of priority. 



