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open vessel containing the bisulphide of carbon should be placed on the grain. This 

 substance is extremely volatile, and the vapor is heavier than air and will permeate 

 the entire mass of grain. Great care must be taken in the use of this substance, as 

 it is extremely inflammable. The carbon bisulphide does no harm to the grain what- 

 ever and the odor is soon lost upon airing, and experiments seem to show that the 

 germinating power is not affected by its use. If the grain can be tightly inclosed 

 for this experiment the amount necessary is small, not more than 1^ pounds to each 

 ton of grain being required. Of course in more open bins or cribs a larger amount 

 will be necessary, and the application will have to be repeated at much shorter 

 intervals. 



Naphthaline and benzine may also be employed, and as the latter is also highly in- 

 flammable, the same precautious are necessary in its use as with the bisulphide. Its 

 action is somewhat slower and larger quantities will need to be used. It will be 

 best to place the naphthaline powder or benzine at the bottom of the bin or bulk of 

 grain. This can be accomplished by the use of tubes. In India hollow bamboo 

 rods are used for this purpose. The naphthaline acts as a repellant, and also has 

 insecticide properties. Benzine acts in the same way, and its insecticide value is 

 much greater, but is inferior to the bisulphide. The use of naphthaline, however, is 

 objectionable, because it gives a more or less permanent odor to the grain. — [Oct. 14, 

 1890.] 



S-weet Potato Root-borer. 



I inclose you in a small tin box some pieces of sweet potato and the bug and worm 

 that has destroyed our sweet potato crop for 3 years in this neighborhood. The bug 

 or worm goes down the vine from above the ground. I find a small hole down through 

 the middle of the vine into the potato. If there is any way to destroy this bug which 

 the Department knows of, it would be a great blessing to this community. — [T. H. 

 Edwards, Bay View, Harris County, Tex. 



Reply. — The insect in question is known as the sweet potato root-borer (C^Zas 

 formicarius) . This insect is treated in the report of the Entomologist, in the annual 

 report of this Department for 1879, page 249. It is a widely distributed insect and 

 has been reported from China, India, Madagascar, Cuba, Louisiana, and Florida, and 

 was doubtless introduced into the United States through Cuba. The early stages are 

 passed in the sweet potato, the eggs being deposited in cavities eaten out by the 

 parent beetles. The larvse burrow in the root in all directions. "When full grown the 

 pupal state is assumed in cavities near the end of the larval burrow and the mature 

 beetle on emerging continues to feed on the potatoes. No remedy has been suggested 

 except the one given in the report cited, which is to dig the potatoes as soon as they 

 are found to be infested and feed those containing insects to stock. — [October 13, 1890. ] 



The Whip-tail Scorpion. 



Yours of the 3d instant duly to hand. In reply will say I am very cautious not to 

 handle the Whip-tail Scorpions with my bare hands. I have never seen the eggs. I 

 found the young specimens under the rain tubs, old wood, etc. They generally have a 

 hole they hide in when I look for them, but dig them out. I often smell the acid odor 

 you mention when I find the large old ones. On one occasion several } ears ago I was 

 holding one on a large chip, taking a good look at him, when he ejected a stream at least 

 afoot upwards, and it fell upon my sleeve about the elbow. I was afraid it would go 

 into my face. I was very careful that he did not turn the hose on me any more. That 

 was the only time I ever saw that operation, and I have handled dozens of them. 

 I do not know if that is one of their means of defense, or whether it was just acci- 

 dental that it so happened. People here mostly are afraid of them. The colored 

 man I referred to in a former letter was the first person I ever heard of that took 

 them in the hand. He said he saw some one handle them, but was afraid of them 

 himself. Some say they apply the poison with the tail after cutting with the big 



