ENVIRONMENT FOR LEPTJNOTARSA 89 



trees, and away down in the hard, yellow clay I found these 

 bugs, apparently dead, but put them in the sun and they im- 

 mediately came to life. They have again made their appear- 

 ance in my garden in large numbers. Last year they ate up 

 everything green on the potato vines, then commenced on 

 the tomatoes, and so on, eating up everything green." 



It seems that the ancestors of these beetles had moved up 

 by short stages from Mexico to Nebraska ; that on the way 

 they ate certain plants that pleased them, but that they knew 

 nothing about potatoes until they reached Omaha City in 

 1859. And here it was that they had their first taste of what 

 seemed to. them a delicious new food. 



They crawled over the potato leaves, nibbled at them, and 

 liked them so well that, ever after, wherever the farmer went, 

 planting his potatoes, there too went the potato-bug beetle 

 to enjoy them. Everywhere the beetle destroyed the crops, 

 and everywhere the farmer did what he could to destroy 

 the beetle. 



It was a hand-to-hand fight, and the record of it is given 

 by Dr. Tower in what he calls " The Chronological His- 

 tory of the Dispersal of Leptinotarsa decemlineata, 1859 

 to 1904." 1 



This record shows how the beetles worked their way from 

 west to east, how long they took for the journey, and how 

 they earned for themselves the nickname of potato bug. 

 Their real name — their scientific name — is Leptinotarsa 

 decemlineata, a name too long for everyday use but quite 

 important to the scientist. 



Here are a few extracts quoted from the record of the 

 travels of Leptinotarsa decemlineata. 



1 This is one division of Dr. Tower's book entitled " Evolution in 

 Chrysomelid Beetles." 



