564 CALIFORNIA ACADEMY OF SCIENCES. 



In the laboratory, from eggs hatched December 15, the 

 larvge first moulted December 29, or fourteen days after 

 hatching. The second moult occurred January 11, the 

 third January 28 — at this time larvae in the trees out of 

 doors were in the second stage, i. e., had moulted but 

 once — the fourth moult occurred February 22, the fifth, 

 March 15, and pupation March 27. The imagines issued 

 April 6 and 7, or ten or eleven days after pupation, agree- 

 ing with the duration of the pupal stages in the fall be- 

 fore. Thus we have the winter passed by the insect in 

 an active larval stage, the evergreen condition of the live- 

 oaks lending itself to such a life history. Out of doors 

 the larval stages were passed more slowly than in the 

 laboratory. At the time of the issuance of the moths in 

 the in-door breeding cages on April 6, larvse just making 

 the third moult were found in the live-oaks. The out of 

 doors larvae began pupation by the middle of May, the 

 moths appearing at the end of the month and during the 

 first part of June. The newly hatched larvse and those 

 in the second stage, in feeding, merely skeletonize the 

 leaves, the soft parenchymatous tissue being eaten, and 

 the firmer vascular tissue being left unattacked. After 

 the second moult, however, all the leaf substance is eaten. 

 The larv£e of the winter and spring were, although 

 abundant, less numerous in many localities than those of 

 the late summer and fall brood. This disparity in num- 

 bers was largely due to the commendable zeal of a partic- 

 ular parasite,* Pimpla behi'endsii Cresson. To a dis- 

 cerning observer the abundance of this parasitic ichneu- 

 mon about the oaks in September was as apparent as the 

 hordes of caterpillars. A resident of Palo Alto com- 

 plained of the large number of "small wasps" (the ich- 

 neumons) which entered his house, and buzzed in the 



^Determined by Mr. L. O. Howard. 



