374 CALIFORNIA ACADEMY OF SCIENCES. 



tain, it feeds exclusively on Ailanthus glandulosa, which 

 by some strange coincidence has been introduced as an 

 ornamental tree into America and into Europe. Without 

 this coincidence the insect would have perished for want 

 of food in its larva state and would not have derived 

 any advantage from its adaptability to different climates. 



Deilephila lineata possesses the advantage of easy adap- 

 tation to climate and to food, combined with the enormous 

 power of locomotion peculiar to its class. It is generally 

 considered indigenous to the old and the new world, but 

 as its organization excludes it entirely from the circum- 

 polar regions it is evident that there must exist another 

 center from which the species has spread. The insect 

 is considerably more common im America than in Europe. 

 Our specimens are larger and show their greater vitality 

 by their power of adaptation in the larva state. 



I infer from these circumstances that the original center 

 from which this showy species spread is on our continent 

 and not in Europe, where the species is comparatively 

 rare, when on our continent it has occasionally developed 

 into what was supposed to be an insect pest, but owing to 

 the very transitory nature of its devastations, can be con- 

 sidered only a fright. The original food of the larva are 

 probably Onagrace^, which group of plants is much 

 affected by the congeners of the Deilephila ' in other 

 climates. In California it shows a predeliction for foreign 

 plants of the same order. It prefers for instance the 

 Fuchsia cultivated in our gardens to our native CEnothera, 

 Godetia, Boisduvalia, etc., without neglecting them en- 

 tirely. It has also adapted itself to Rumex and Polygonum, 

 to Purslane and its relations, Claytonia and Calandrinia. 

 It has been discovered in great numbers by Mrs. Brandegee 

 in the Gila desert, feeding on a species of Lupine, and has 

 occasionally frightened our winegrowers by attacking, in 



