170 



Phytomonas saliciperda (Lindeijer) Magrou 



Insect concerned: The willow "borer , Cryptorrhynchus 

 lapathl . 



Lindeijer (1932) descrl"bed a "bacterial disease of 

 willows ( Salix spp. ), caused "by Pseudomonas saliciperda , 

 and since placed in genus Phytomonas . 



According to Leach (19^0), the disease causes a wilt of 

 the "branches followed "by early defoliation and death of 

 the affected limbs. Natural infections most frequently 

 originate at the sight of wounds made "by the willow "borer, 

 which, after having "been contaminated with the "bacteria, 

 infects the tree. The disease has "been experimentally 

 produced "by allowing infected insects to feed on willow 

 twigs. 



For a description of this organism see Bergey's Manual 

 (5th ed., p. 20*0. 



Leach, J. G-. 19^+0 Insect transmission of plant diseases. 



6l5 pp. McGraw-Hill Book Company, New York. 

 *Lindeijer, E. J. 1932 De "bacterie-ziekte van den wilg 



veroorzakt door Pseudomonas saliciperda n. sp. Thesis 



Univ. of Amsterdam, Baarn, pp. 1-82. 



Phytomonas savastano i (Smith) Bergey et al. 

 Insect concerned: The olive fly, Dacus oleae . 



Phytomonas savastano i gives rise to a disease of olive 

 tree on which "knots" or galls result from the infection. 

 The disease is prevalent in Italy and other southern Euro- 

 pean countries, although Smith isolated cultures from olive 

 galls collected in California where the disease has "been 

 known since 1898. 



In Italy there appears to "be a close association "between 

 the olive fly, Dacus oleae, and the spread of the disease. 

 Petri (1909, 1910) studied the relationships between this 

 insect and "bacteria found in the intestinal tract of the 

 insect. Ascohacterium luteum (which see) is one of the 

 nonpathogenic "bacteria which Petri found occurring as a 

 "symbiote" in the olive fly and from the four "blind appen- 

 dages of the middle stomach of the larvae of Dacus oleae , 

 he (1910) isolated Bacterium savastanoi ( Phytomonas savas - 

 tanoi ) . According to Buchner (1930) the latter organism 

 is the real "symbiont" associated with the olive fly. The 

 "bacteria are transmitted through the egg and persist in 



