﻿OF THE STATE ENTOMOLOGIST. 125- 



known to infest several other species of Oalopteni. None of these 

 enemies are so effectual in their work as the mites andTachina-flies. 



REMEDIES AtJAIXST THE UNFLEDGED INSECTS. 



The war waged against the young insects last Spring was ener- 

 getic and untiring, and everything that human ingenuity could con- 

 ceive was employed in the conflict. Trapping, burning, tramping, 

 poisoning, trenching, were all resorted to. In some cases whole acres 

 were surrounded with boards and the insects imprisoned until they 

 starved, while in others coal tar was smeared on to fences and out- 

 houses in order to hold fast the newly-hatched swarms that settled 

 thereon. 



The means to be employed against the ravages of this insect in 

 the more fertile country subject to its periodical visitations, but in 

 which it is not indigenous, may be classed under five heads : 1. Nat- 

 ural agencies; 2. Artificial means of destroying the eggs; 3. Such 

 means of destroying the unfledged young; 4. Remedies against the 

 mature or winged insects ; 5. Prevention. Having considered these 

 measures last year, I shall treat here principally of the second, third 

 and fifth, bringing together the more valuable experiences of the 

 year. In a paper on "The Locust Plague : How to avert it," read be- 

 fore the American Association for the advancement of Science last 

 August, I wrote as follows : 



Artificial Means of Destroying the Eggs. — The fact that man can accomplifh most in 

 his warlare aofainst locusts by des^troying the eggs has long been recognized by Euro- 

 pean and Asiatic governments liable lo suffer troni the insects. The eggs are laid in 

 masses, just beneath the surface ot the ground, seldom to a greater depth than an inch ; 

 and high, dry ground is preferred for the purpose. Very otten the ground is so com- 

 pletely filled with these egg masses, that not a spoonful of the soil can be turned up 

 without exposing them, and a harrowing or shallow plowing will cause the surface to 

 look quite whitish as the masses break up and bleach from exposure to the atmosphere. 

 Great numbers will be destroyed by such harrowing or plowing, as they are not only 

 thereby more liable to the attacks ot natural enemies, but they lose vitality through 

 the bleaching and desiccating influence ot the dew, and rain, and sun. If 

 deeply turned under by the plow, many of them will rot, and the young that 

 chance to hatch will come forth too late the next year to do much harm — providing the 

 same ground be not re-turned so as to bring the eggs to the surlace in the Spring.* 

 Excess of moisture for a few days is fatal to the eggs, and they may very easily be de- 

 stroyed where irrigation is practicable.f Where stock can be confined and fed on soil 

 filled with !-uch egg?, many of these will be destroyed by the tramping. All these 

 means are obviously insulHclent, however, for the reason that the eggs are too often 

 placed where none of them can be employed. In such cases they should be collected 

 and destroyed by the inhabitants, and the State should offer some inducement in the 

 way of bounty lor such collection and destruction. Every bushel of eggs destroyed is 

 equivalent to a hundred acres of corn saved, and when we consider the amount of des- 

 titution caused in some of the Western States by the locust invasion of 1874, and that 

 in many sections the ground was known to be filled with eg^is; that, in other words, 

 the earih was sown with the seeds of future destruction — it is surprising that the legis- 



*The beneficial results of plowing under or turning up the eggs are fully demonstrated in tho 

 report of the Minnesota Commission. 



fThe efficacy of irrigation or inundation in destrojing the eggs will, of course, depend very 

 nuich on tlie character of the soil, and may be of little service in a tenacious clay. 



