FAUNA AND FLORA OF CALIFORNIA. 375 



company with the larva of ChcBrocmn-pa Achcemon, the 

 grapevine. In regard to the latter circumstance, I have 

 to take the part of the Deilephila larva, as much more 

 mischief is done by the Choerocampa, which feeds ex- 

 clusively on the grapevine, when Deilephila generally 

 prefers the weeds of the vineyard. 



The caterpillar is frequently mistaken for the army- 

 worm, which term is correctly applied to the larvae of 

 different Agrotides, which are much smaller but consider- 

 ably more dangerous than the formidably looking Deile- 

 phila, whose devastations are exceedingly transitory. 



The Indians eat the caterpillar, and that to my opinion 

 is another proof of its American birthright, as all savages 

 avoid eating animals which they do not know for genera- 

 tions. 



I have here to mention another insect, which, originally 

 very rare, gradually has developed into an insect pest, 

 without possessing any advantages in regard to locomo- 

 tion, nor powers for adaptation in regard to food or 

 climate. 



It is Phryganidia Calif 07-nica, a type most interesting to 

 the student of systematic entomology, but without any 

 attraction as to beauty. 



This insect feeds on oaks, formerly exclusively on live- 

 oaks, but since these oaks have diminished in number, in 

 proportion to the insect having multiplied the larva has 

 begun to invade lobata and Kelloggii, but there its power 

 of adaptation to new food stops. 



I do not know how many generations in a year are pro- 

 duced by the insect. I have counted four, but am certain 

 there is at least one more. 



In consequence of these many generations the destruc- 

 tion of leaves extends over the whole year, and the poor 

 tree has scarcely produced a new crop of leaves, when it 



