KATYDIDS INJURIOUS TO ORANGES IN CALIFORNIA. 6 
1911 and 1912 showed the injury to be very widespread. Very few 
orchards were examined which failed to indicate the presence of this 
katydid by the unsightly chewed fruit, either in the boxes or dis- 
carded as worthless upon the ground about the trees (PL II, fig. 2). 
In 1912, before the picking season commenced, an examination was 
made of all the fruit on 10 or more trees in each of 53 orchards of 
Washington navel oranges scattered throughout the orange district 
to determine the total injury to the mature fruit. Only 3 of these 
orchards were entirely free from katydid-injured fruit. In 3 of the 
remaining orchards the damage, though present, amounted to less 
than 1 per cent. In the remaining 47 orchards from 1 per cent to 39 
per cent of the maturing crop was rendered totally unfit for sale by 
the katydids. Fourteen of the 47 orchards suffered a loss of 10 per 
cent or more of the crop. The total loss of fruit from this cause for 
the 47 orchards averaged 8.2 per cent of the entire maturing crop. 
These estimates do not, of course, include the very young fruits 
which are completely destroyed soon after the petals are off, and 
this loss is rarely noted at all by orange growers. 
The orchards in which the injury is excessive are not necessarily 
in isolated locations, as has been supposed, nor are they growing 
under any unusual conditions. The katydid, however, appears to 
be slightly more abundant in the foothills regions, and it shows some 
preference for young and vigorously growing orchards. 
Several groves which had previously suffered but slightly from 
katydids were called to the attention of the writers in 1911 and 1912 
because of the increasing injury. Thus an orange grower informed 
the writers that he had seen the familiar circular holes cut in the 
fruit by katydids on his place for 14 years. Such a small percentage 
of fruit was affected, however, that he had paid no special attention 
to it until the fall of 1911, when he noted a material increase in 
injury. Just after the crop was picked in 1912 a visit was made to 
his orchard and the injury found much worse than in 1911. The 
pickers had just finished a 6-acre plat of young navel trees, from 
which they had discarded 12,000 oranges because of katydid injury. 
About 100 boxes of oranges were therefore ruined in this 6-acre block 
of trees, and as 800 boxes of good oranges were picked from these 
trees a complete loss of 11 per cent of the mature crop plus an 
undetermined percentage of young fruits and blossoms which might 
have become fruit was sustained. A 15-acre orchard of young 
Washington navel trees, which were but slightly infested in 1911, 
became seriously infested in 1912. Y/hen the final picking was made, 
533 boxes of good oranges were secured from the orchard, while 
approximately 175 boxes, 21,000 oranges by count, were rejected as 
worthless because of splits, gashes, and holes caused by katydids. 
The most striking example of injury by this katydid that has come 
to the attention of the writers was that of a navel-orange grove so 
