234 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



devastation, until at last, if very numerons, they devour every green 

 thing over extensive districts. Whenever they have thus devasted a 

 country they are forced to feed upon one another, and perish in immense 

 numbers from debility and starvation. Whenever timber is accessible 

 they collect in it, and after cleaning out the underbrush, feed upon t'ho 

 dead leaves and bark. A few succeed in climbing up into the rougher- 

 barked trees, where they feed upon the foliage, and it is amusing to see 

 with what avidity the famished individuals below scramble for any 

 fallen leaf that the more fortunate mounted ones may chance to sever. 

 This increase in destructiveness continues until the bulk of the locusts 

 have undergone their larval molts and attained the pupa state. The 

 pupa, being brighter colored, with more orange than the larva, the insects 

 now look, as they congregate, like swarms of bees. From this time on 

 they begin to decrease in numbers, though retaining their ravenous 

 propensities. They die rapidly from disease and from the attacks of 

 natural enemies, while a large number fall a prey, while in the helpless 

 condition of molting, to the cannibalistic proclivities of their own kind. 

 Those that acquire wings rise in the air during the warmer parts of the 

 day, and wend their way as far as the wind will permit toward their 

 native home in the Northwest. They mostly carry with them the germs 

 of disease or are parasitized, and wherever they settle do comparatively 

 little damage." 



DIRECTIONS IN WHICH THE YOUNG LOCUSTS TRAVEL. 



The young insects when migrating move, as a rule, during the warmer 

 hours of the day only, feeding, if hungry, by the way, but generally 

 marching in a given direction until toward evening. They travel in 

 schools or armies, to no particular or constant point of the compass, but 

 purely in search of food — the same school one day often pursuing a dif- 

 ferent course from that pursued the day previous. On this point the 

 experience of 1875 as well as of 1877 is conclusive, though the bulk of the 

 testimony as to their actions, when hatching out in the more northern 

 States, is to the effect that the prevailing direction taken is south or 

 southeast, while in Southern Texas it is just opposite, or north. A per- 

 son traveling along a road may often see one army marching in one 

 direction to the left and another in the opposite direction to the right, 

 and we have repeatedly had such an experience. 



If, from any reason whatsoever, the vanguard of a column changes 

 its course, the changed direction is in some way communicated in wave- 

 like form to those in the rear. Usually, the front of a column is not 

 easily diverted, however, but will pass through such obstacles as open 

 fences rather than change course. Sometimes two schools going in dif- 

 ferent directions will cross each other, the individuals of either keeping 

 to their particular course and presenting a singular spectacle as they 

 hop past one another. 



It is recorded in Europe that few things, not even water, stop the 



