SiC Eee, -i "жа a E Е so mR Mica EE тав E AA T EES. 
TWO TRUNK DISEASES OF THE MESQUITE 
HERMANN VON SCHRENK 
Pathologist to the Missouri Botanical Garden 
The diseases of the mesquite (Prosopis glandulosa Torr.) 
hitherto recorded are comparatively few in number; Heald and 
Wolf (5) enumerate seven from southern Texas as due to fungi. 
The pods are frequently affected by an anthracnose, Gleosporium 
leguminum (Cke.) Sacc.; the leaves are attacked by Cercospora 
prosopidis Heald and Wolf, a species of powdery mildew (Ету- 
siphe ?), and by a rust, Ravenelia arizonica Ell. & Ev.; and a 
leaf blight due to some unknown cause is also mentioned. The 
large limbs and smaller branches show galls, evidently not due 
to insect attack, and the mistletoe (Phoradendron flavescens 
(Pursh) Nutt. is sometimes destructive. In addition to the 
above, the writer has frequently noted the weakening effect, 
particularly near the ends of branches, brought about by vigor- 
ous growths of the ball moss (Tillandsia recurvata L.). Birge 
(1) has given a good description of the effects of this plant on 
trees in Texas. 
Of the insect injuries of the mesquite, that of the mesquite 
borer (Cyllene antennatus White) is of interest. The insect is 
described by Horn (6) as attacking mesquite wood in Arizona, 
but no description of its work is given. While I have not seen 
the insect at work in Texas, the holes found in the mesquite 
trees are so like those described for other species of Cyllene, 
notably Cyllene robinie Forster (10)—which attacks the locust 
—that the assumption seems warranted that the Texas insect 
is the one referred to by Horn. The tunnels extend straight 
through the bark into the heart-wood, and up and down in the 
latter, thus forming ideal channels for the entrance of fungous 
spores. 
The only reference to trunk diseases which has been found is 
a brief statement by Havard (4), in an account of the mesquite, 
in which he mentions that ‘‘unfortunately it too often happens 
that the zones of the heart-wood are fissured, decayed or de- 
ANN. Mo. Вот. Garp., Vou. 1, 1914 (243) 
