August, '17] ESSIG: TOMATO AND LAUREL PSYLLIDS 439 



All experiments with lime-sulphur should be first tested on a small 

 scale before extensive applications are made. Fortunately, the 

 insect in question seldom if ever deserves control measures in this state. 



Bibliography and Synonymy 



Sale, Acta Soc. Entom. Bohemise, VI, pt. 4, pp. 102-lOS, 1909, Trioza (Original 



description and 1 plate). 

 Crawford, Pomona Jr. Entom. Ill, No. 1, pp. 446, 448-450, Feb. 1911 (2 



figures). 

 Johnson, Colo. Agrcl. Exp. Sta. News Notes, 1911 (Tomato psyllid). 

 Patch, Bui. 202, Maine Agrcl. Exp. Sta., pp. 231-232, 1912 (2 figures). 

 Crawford, Bui. 85, U. S. Nat. Mus., pp. 71-72, 1914 (6 figures). 



Paratrioza ocellata Crawford, Pomona Jr. Entom. II, No. 2, p. 229, May 1910; 



also Pomona Jr. Entom. Ill, No. 1, pp. 447-448, Feb. 1911 (5 figures). 

 Paratrioza pulchella Crawford, Pomona Jr. Entom. II, No. 2, p. 229, May 

 1910; also Pomona Jr. Entom. Ill, No. 1, p. 447, Feb. 1911 (Sj-nonj'm of 

 Paratrioza ocellata Crawf.). 



The Laurel Psyllid 



Trioza alacris Flor 

 (Plate 20, figs. 3, 4 and fig. 23) 



The laurel psyllid has been the cause of considerable loss to nursery- 

 men in the San Francisco Bay region and has received the attention 

 of local authorities since 1911 when it was first discovered. It was 

 evidently imported from Europe where it has been known as a pest 

 for many years. As an enemy of the laurel it is very pernicious and 

 not only disfigures the foliage, but causes smutting and greatly stunts 

 the plants. Its presence means continued and expensive control 

 measures or very unsightly trees if nothing is done. As the laurel is a 

 favorite ornamental tree and grown generally throughout the state, 

 anything that tends to make it less beautiful should be known and its 

 further dissemination avoided. 



Though the known distribution^ is limited it cannot be long confined 

 to its present areas. Local horticultural authorities are endeavoring 

 to prevent its spread and they are doing much in this direction, but 

 there must be more than local action to make a safe guarantee to the 

 rest of the state. It is sincerely hoped that the few small infestations 

 might be entirely stamped out while this is still possible, before they 

 become too large. 



1 Since preparing this description the author has received specimens of the adults, 

 nymphs and work of this insect on Laurus nobilis from Dr. A. G. Smith of Pasadena, 

 California. This is the first record from the southern part of the state and indicates 

 the possible establishment elsewhere in the state. 

 Sept. 29, 1916. 



