LECTURE ON ENTOMOLOGY. 



BY PROF. C. V. RILEY, STATE ENTOMOLOGIST OF MISSOURI. 



Ladies and GtENTLEmex, — Eight years ago, I wrote my maiden essay for 

 the State Horticultural Society, of lUiuois, ou the codling moth. It was 

 read by that veteran horticulturist who has been carrying on his investigations 

 this last summer in Germany and Austria, — and whose presence we all miss here 

 to-night, — Dr. Waters. To the kind approval which that essay met, I owe nO' 

 little of that enthusiasm which has, since that time, sustained me in my 

 efforts to unlock nature's secrets. I am i:)roud to say that there was not a 

 single fault of commission in that article; but since then we have learned 

 much that was then unknown about this codling moth. 



I will present to you the more important facts; I cannot give you a full 

 account. It would occupy more time than we shall have to-night. 



First, This codling moth is an imported insect. There was a time when it 

 had no existance in this land, and it furnishes us with an excellent illustration 

 of the importance of preventing the importation of noxious insects. If we 

 had had the knowledge we now have, we might easily have prevented its intro- 

 duction, thus saving the immense loss which it has caused. The mellowing 

 and vivifying influence of the vernal year causes our codling moth to burst 

 the silken cerements which had held and enwrapped it during its long winter 

 torpor and sleep. After meeting her mate, the female flits from tree to tree, 

 and deposits her eggs in the calyx of the new-formed fruit. 



I have here a sketch showing the dilFerent stages through which it goes. In 

 a few days this egg produces an insect which makes for the heart of the young 

 fruit. There it riots around the core, causing perforations and excavations 

 filled with its own excrement. It takes about twenty or thirty days to attain 

 its full growth. It has then changed color, and the head and cervical 

 shield, which were formerly black, have become brown. This larva now issues 

 from the fruit. It generally leaves the fruit during the night, either by letting 

 itself down by a silken web, or by crawling down the trunk of the tree, — 

 about half get to the ground one way, and half the other. Its object in 

 descending the tree is to find some sheltered spot in which to spin its cocoon. 

 Having found this place, it begins to spin its cocoon, which it always covers 

 on the outside Avith the particles of the bark of the tree. The normal spin- 

 ning place is under the loose scales of bark of the tree, so that it is very difiB- 

 cult to find it. Within this cocoon the larva changes to a chrysalis. This 

 stage lasts about twelve days, during which time it remains without food or 



