418 MINNESOTA STATE HORTICULTURAL SOCIETY. 



Early in spring- it feeds vipon the former, later upon the latter sub- 

 stances. Knowing- this, we can kill large numbers of the curculios 

 which appear earlj' in spring, and we should aj)ply the spra 3' before 

 the trees are in bloom. As the bee-keepers are also in session I 

 will add here: Never spray trees while in bloom. The little Turk 

 deposits eggs inside the fruit, and never upon it. Cousequentl}^, the 

 larvae can not be reached bj^ anj' application of poison to the growing 

 fruit. Yet as the beetles continue to deposit eggs for a long time 

 they must necesserily take some food, and with the view of poison- 

 ing this food, at least two sprayings should be made after the fruit 

 has set. Such spraj'ing will kill also most other insects that enjoy 

 the foliage of plums, and, consequentlj'^, is a verj^ useful and neces- 

 sary operation. Of course, we have to be satisfied with killing a 

 large number of plum-curculios, but we cannot expect to eradicate 

 them by such means. Either Paris green or London purple may be 

 used; each has advantages and disadvantages. If we use the latter 

 w^e should add an equal weight of quick-lime to prevent the injur- 

 ious action of soluble arsenic. Every fruit-grower should have a 

 good spraying machine, if possible with a Verinorel nozzle. One 

 pound of either poisons in 175 to 200 gallons of water is an excellent 

 proportion, providing the sprajdng is done tso thoroughly that every 

 part of the tree it wet. 



"All fallen fruit should be picked up" is a rule that should be 

 strictly followed. Those horticulturists that have tiine — if such 

 persons exist — should also use the old remedy of jarring their 

 plum trees early in the inorning, and gather and destroy the insects 

 that fall upon a canvas spread under it. 



The Plum-gouger (Coccotorus pruaicida) is also a snout-beetle, 

 but has quite different habits and differs also greatly in appearance 

 The plum-gouger makes a deeper and smaller puncture in the fruit 

 when depositing its eggs, and there is never an indication of the 

 crescent-shaped cut so artfullj^ made bj^ the little Turk. Its larva is 

 also never exposed, but instead of feeding upon the flesh of the plum, 

 it feeds inside of the stone upon the flesh of the kernel. Inside this 

 stone, it reaches the adult stage in the fall, while the mature larva 

 of the plum-curculio leaves the plum and enters the ground for 

 .pupation. Removal of fallen plums is absolutely necessary to 

 reduce the numbers of this insect. There is very little use in spraj'- 

 dng; jarring the trees is the best method of capturing- most of our 

 foes. A cU)sely allied species breeds in our sand-cherries; it has 

 almost identical habits. 



There is a remarkable difference in the egg-laying habits of the 

 two plum insects, as you can see by studying the figure 5. I have 

 also indicated the method that a third species of snout-beetle has in 

 la5'ing eggs in apples. 



Plum-tree Aphis (Aphis pruaifolice) and Plum Aphis (Myzus 

 persiccc) both occur in Minnesota, but the latter is the more common 

 and injurious. When numerous, these lice distort the leaves and 

 tender twigs, and b}^ clustering upon the 3'oung plums cause them 

 to wither or become hard. As a general rule, thej' are well hidden in 

 the curled leaves and are not readil}- reached bj' dr}' or wet insecti- 



