WINTER NUMBER 35 
this species on camphor and compares it with the possible mor- 
tality it suffered on citrus, from both defoliation and low tem- 
peratures, it is very doubtful if more than one insect in ten thou- 
sand survived. In fact, it would be nearer the truth to say that 
not more than one in a hundred thousand survived the cold. 
It has been impossible to make observations on this species in 
group three. 
THE RusT MITE (Hriophyes oleivorus ASHM.) 
At the time of the cold wave there was an abundance of mites 
present ; many more than is ordinarily the case at that season of 
the year. These were partially frozen and partially killed be- 
cause the foliage was shed. 
Examinations were made at Orlando during the cold wave, on 
February 3, or after the first cold night, and before the second 
one. No mites could be found on a small sour tree, located in an 
exposed situation, on which many thousands had been present all 
season previous to the frost. On February 7th examinations of 
green leaves, still on the trees, showed the mites were very scarce 
compared with the number present before the frost. 
The rust mite cannot live on dead fallen leaves. On February 
10th green leaves picked up from the ground were examined and 
no living mites were found. On the same day 17 living mites 
and three eggs were found on 10 leaves from a tree in a protected 
location. On 24 green leaves from the trees, 4 living mites were 
found and from 17 green leaves picked from the ground, 1 living 
mite was present. No mites were ever found on dry leaves. 
There is no doubt that the rust mites present on the trees and 
fruit now are the progeny of those that survived on the leaves 
uninjured by the frost. 
In the counties of group one the mites were nearly exterminat- 
ed. Those that were not actually frozen perished with the drying 
of the leaves. In examining six groves, May 3 to 6, in two days 
only two mites were observed. In a normal infestation there 
would have been literally billions present. In Marion County, on 
May 24th, they were also extremely scarce. 
In the counties of group two they received a severe setback. A 
conservative estimate of the mortality would be more than 99%. 
In fact, on June 1, or more than four months after the frost, 
they have only become as abundant as they were before the cold 
wave. Since the freeze the weather has been extremely favorable 
for the reproduction of the mites, and this pest is so abundant 
(Continued on page 38) 
