No. 6. DEPARTMENT OF AGRICULTURE. 15S 



DEPAIJTME^'T OF AGRICULTURE— DIVISIONS' OF ZOOLOGY 



THE APPLE SEED CH ALOIS 



(SYNTOMASPIS DRUPARUM) 



This is a small green-colored gnat-like insect, in its mature state 

 about one-eighth of an inch in length. The eggs are deposited in the 

 seeds of apples when the fruit is one-half inch or more in diameter. 

 On warm sunshiny days in June the female alights upon the young 

 apples, and drives her long ovipositor into the apple, through the 

 flesh and into the seeds. The eggs are pure white, and hard to see in 

 the young seeds. From the eggs hatch grub-like larvae, having brown- 

 ish heads. They feed on the soft contents of the kernels until Septem- 

 ber, at which time they become full grown larvae, having devoured 

 the entire kernel of the seeds. They pass the winter inside the seed 

 shells in the pupae state, emerging from the apple as mature insects 

 early in the following summer. 



The damage done to fruits by the Chalcis consists principally in 

 dwarfing and gnarling the apples in a characteristic manner. In- 

 fested apples are not only undersized, but misshapen, and lacking 

 in symmetry. The i^oint at which the eggs were introduced appear 

 as a black dot occupying a depression on the surface of the fruit. 

 From These punctures a brownish line of hardened tissue extends to 

 the infested seeds. 



Treatment: Since the insects remain in the seeds throughout the 

 winter, it is necessary to destroy the apples left under the tree in 

 the fall, as well as such as remain upon the tree. The complete de- 

 struction of all such apples grown, both in the orchard and of seed- 

 lings elsewhere, will proA'e an effective remedy where this practice 

 is followed generally in infested localities. 



(g) Carton Bisulfide for Ro mid-headed and Flat-headed Apple-tree 

 Borers. Our experiments have proven conclusively the correctness of 

 our recommendation to use carbon bisulfide for the round-headed and 

 flat-headed borers Avhich infest apple, pear and quince trees. It is 

 to be noted that this is not recommended for the borer of the peach, 

 which is discussed above, and for which we have found an adequate 

 preventive. 



Carbon bisulfide is a clear, foul-smelling, heavy liquid which readily 

 volatilizes and of Avhich the fumes are ofl'ensive, poisonous and ex- 

 plosive. It is not quickly poisonous as hydrocyanic gas, and it is 

 much more safe to use, but fire should be kept away from it. It is 

 not a preventive of borers as is the lime-sulfur wash, but is used 

 as a remedy for them after tliey have entered the tree. 



The proper method of using it is to put the liquid in a spring 

 bottom oil can, and insert the tip of the can into the hole of the l>orer. 

 and inject a jei of the liquid and close the hole with clay, mud, putty 

 or grafting wax. 'SMiere the hole is large and irregular a wad of 

 cotton can be satured with the carbon bisulfide, and held \Xi place 

 by a handful of mud fastened over it against the tree. 



