54 



of its existence, and whatever insects are captured are on the whole 

 decidedly beneficial. This practice then is a positive injury, in that it 

 systematically, destroys beneficial insects without accomplishing' any 

 good as a recompense. This measure, so commonly practiced by plant- 

 ers, should, in view of the decided and constant harm attendant upon 

 its use, be unhesitatingly condemned whenever opportunities are pre- 

 sented for doing so. 



INSECT DISEASES. 



In order that any insect disease should be most efficient and prac- 

 tical, it is necessary that the pest to be infected be gregarious in habit 

 and travel freely enough to intermingle frequently. For the Boll Worm 

 both of these conditions are found directly by opposites, it being soli- 

 tary in habit and not traveling about as frequently as most species of 

 worms of economic importance do. 



Furthermore, feeding on the inside of the portions attacked their 

 chances for infection through natural agencies and communication with 

 diseased worms are proportionately decreased. Even should a Boll 

 Worm become diseased, in the majority of cases it would die in a boll 

 or ear of corn and the deliquescing portions of the body containing the 

 germs would be absorbed by the rotting or fermenting boll. No other 

 worm, therefore, is ever exposed to infection from it. The solitary hab- 

 its of the Boll Worm in the midst of suitable plants offering a great 

 plenty of food furthermore insures the most healthy and least acciden- 

 tal condition possible. None of the factors, such as excessive numbers, 

 often resulting in a scarcity of food, thereby reducing the vitality of 

 the worm, enter into consideration in the case of the Boll Worm. All 

 or any of these are conditions which greatly favor the propagation, in- 

 fection, and distribution of diseases. These facts concerning the num- 

 bers and food-habits of the Boll Worm make it impossible to accom- 

 plish anything in a practical way with this species, even though the 

 diseases in question were highly contagious and efficacious as destruc- 

 tive agencies. The reason, as already stated, consists in the fact that 

 there are certain conditions required in order that contagious diseases 

 can be introduced and disseminated, and those conditions are wanting 

 in this species. 



Again, if there were any contagious insect diseases of economic im- 

 portance prevalent in the cotton belt they would before this time have 

 made evident their efficacy, especially when it is considered how long cot- 

 ton and other crops have been under cultivation, and which have been so 

 long ravaged by all the various insects, from some of which we might 

 expect the occurrence and spread of disease. There are such diseases 

 found in the cotton region, and they have been found in such localities 

 as to make infection possible under the conditions as above stated. By 

 observation it has been determined that occasionally Boll Worms do die, 

 and apparently from disease. Whether peculiar to the species or due 



