SPRAYING FOR THE CITRUS MEALY BUG 255 



of eggs are deposited, while only those at the extreme end are exposed. The 

 "working-in" process often causes a great deal of dry rotting. In one orchard 

 about 15% was thus destroyed. The pests lodged in the navel are removed 

 with the fruit, and it is impractical to spray except at the following times : 



1. Just after the fruit is well set and continue, if necessary, until the 

 fruit attains the size of a walnut : At this period the mealy bugs are mostly 

 young and are scattered individually over the trees. It is useless to spray 

 after the navel is large enough to afford extensive shelter, for this is where 

 the insect is sure to lodge as soon as possible. 



2. After the fruit is picked : It is a plain truth that the mealy bug, on 

 the citrus trees, is a fruit feeder. For this reason it appears in greater 

 numbers upon the lemon trees, for lemons bear fruit throughout the entire 

 year, and afford the most favorable conditions. 



After the oranges are removed from the trees, it is difficult to find the 

 mealy bug in any considerable numbers. Of course many go with the fruit, 

 but enough egg masses are left upon the trunks and limbs of the trees to 

 infest the coming crop of fruit. And the pest will not show up again until the 

 fruit is well set. This period of inactivity, due to lack of food, has led many 

 to believe that the pest left the tree, to show up only at certain periods of 

 the year. Not remembering the conditions from year to year, many orange 

 growers believe that the mealy bug may disappear for a year before it again 

 shows up. This is not so true with the lemon grower. While the insect is 

 not so numerous in the summer months, it is always present, and a constant 

 source of worry. It may be found upon the orange trees, but, being small and 

 not so active, is more difficult to iind than when you have only to look into 

 the navel of the fruit. 



To show this preference for the fruit the following experiment was car- 

 ried on in the laboratory : Several two-year-old lemon trees, and seedling 

 orange trees, were enclosed in cloth cages and kept in excellent condition. 

 Large numbers of infested lemons and oranges were placed at the base 

 of the trees. In no case did the mealy bugs leave the fruit, until it had 

 become shriveled and tough-skinned. And when the young did take to the 

 tree their development was extremely slow. In two cages, I have had mealy 

 bugs infesting the young lemon trees since October. The young hatched 

 out in great numbers in a month later and fairly covered the foliage of the 

 tree. To date (June 7) not a single adult insect can be found, while there are 

 still a few small individuals. This is not true on other plants, where they de- 

 velope perfectly upon the foliage. Thus they linger upon the orange trees until 

 the fruit appears when they begin to develope very rapidly. Conditions may 

 vary elsewhere, but this one thing is very noticeable here. 



Valcncias and Sccdiiiii:; Trees: As in the case of the navels, the mealy 

 bugs gather at the blossom end of the fruit, where they deposit a great many 

 eggs. In the seedling, however, little or no protection is afforded except 

 against the weather. The damage to the fruit is slight and the insects are 

 easily removed in the washer. The greate.st damage done is causing the 



