ART. 10 GALL-INHABITING CYNIPID WASPS WELD 49 



On May 7, 1924, A, O. Larson collected more material of this 

 species from a cork oak tree on North Orange Grove Avenue, Pasa- 

 dena. Flies were emerging when this was received at Washington, 

 May IT. When he revisited the tree on May 22 practically all had 

 emerged and many of the twigs had died but still retained their 

 leaves, badly disfiguring the tree. This tree is about 18 inches in 

 diameter and undoubtedly planted about 25 years ago by the archi- 

 tect, not by the gardener v.dio planted most of the ornamentals on 

 the place. 



As the gall resembles that of a European Fioriella on cork oak, 

 galls and flies were sent to Prof. J. S. Tavares in Spain, who is 

 familiar with the galls of the Iberian peninsula, thinking possibly 

 this might be that European species which had been brought over 

 years ago in the twigs of a young tree imported from Spain. But 

 he did not know the gall, nor was the insect a Fioriella. No record is 

 at hand of the introduction of the cork oak except by importation of 

 acorns. There are said to be over 1,000 cork oak trees in the San 

 Gabriel Valley descended from two trees on the Richardson farm at 

 Alhambra grown from acorns sent to Don Benito Wilson by the 

 Commissioner of Agriculture in 1860. It seems probable that this 

 is a native Cynipid which has come over from the native oaks on to 

 this introduced exotic ornamental tree, although all the galls of this 

 type known to the writer on the native oaks are produced by entirely 

 different genera. 



Another tree infested with the galls of this species was dis- 

 covered by Louis Kroeck in May, 1924, standing in a lumber j^ard — ■ 

 once a recreation park — in Santa Clara on land that once belonged 

 to the mission. In April, 1924, Eric Walther found another in- 

 fested tree in Golden Gate Park in San Francisco. He writes : 



This tree is about 35 years old and lias evidently been suffering severe injury 

 for years, the 2-year-old twigs being so heavily infested that they die and the 

 first heavy storm causes them to break off, and so the tree looks as if \t had 

 been pruned annually. 



PLAGIOTROCHUS SERRICORNIS (Kinsey) 



Andricus serricornis Kinsey, Bull. Amer. Mus. Nat. Hist., vol. 46, 1922, p. 288, 

 pi. 24, fig. 3. 



The galls of this species have been collected by the writer on 

 Q. agrifolm in the Santa Ana, Santa Monica, and San Gabriel 

 Ranges, at Pasadena, Santa Anita (contained pupae April 20, adults 

 emerging April 27), Newhall, Piru (flies emerging April 25, 1918), 

 Fillmore, Ojai (galls about half grown on April 7, 1922), Carpin- 

 teria, Montecito, Santa Barbara, Gaviota, Santa Margarita, Paraiso 



