LOUISIANA CIRCULAR No. 6. 43 



the first larva of an American horsefly was described more than 

 thirty years ago, and that since that time many economic ento- 

 mologists in all parts of the country have been investigating 

 all manner of subjects with which insects are concerned, we 

 hardly know how to explain the fact that so little is really 

 known about these stages. 



If all species were alike in their habits, a knowledge of the 

 immature stages of one species would make it an easy matter 

 to work out the life histories of the others. The fact that so 

 few have been worked out is proof in itself that all species are 

 not alike; and when one undertakes the study of a particular 

 species, in addition to those wdth which he already claims an 

 acquaintance, he is not only convinced that the immature stages 

 of two species may be different, but that they may have scarcely 

 a single habit in common. 



Horseflies are a recognized pest in all parts of the world, 

 and although it is difficult to estimate the damage done by them, 

 every farmer and stock-raiser admits it to be considerable. It 

 is a fact that all remedies that have been suggested are unsatis- 

 factory in a measure, but it is quite possible that by continued 

 study and investigation of the problem effective remedial meas- 

 ures may be developed. 



