REPLY TO A CIRCULAR NOTE TO WORKING 

 ENTOMOLOGISTS." 



In replying to the question proponncled by jNIr. Robert 

 H. Lamborn, whether dragon flies may not be artificially 

 multiplied to such extent as to become an important fac- 

 tor in the destruction and consequent diminution of flies 

 and mosquitoes or other noxious insects, the entomologist 

 finds himself confronted at the threshold of the discussion 

 by the necessity of making special investigations into the 

 life histories, and relations to man under his present con- 

 ditions of civilized existence, to Nature in general, and to 

 each other, of each of the insects above named before 

 definite conclusions can be reached. 



The artificial rearing from generation to generation of 

 any insect requires the duplication, or some equivalent, of 

 the following natural conditions : — 



1. Ovum. 



1. Conditions under which copulation and fertilization 



of ova occur. 



2. Conditions under which oviposition will occur. 



3. Conditions under which ova will hatch. 



2. Larva. 



4. Conditions necessary to aiford food supply to larvae. 

 6. Conditions for maintenance of natural element or 



surroundings of larvje. 



(71) 



