THE AMERICAN ENTOMOLOGIST. 



263 



in its habits, demands deep and protracted 

 irrigations during certain periods of its 

 growth. Hence the fields, which are gener- 

 ally very level, are sometimes entirely sub- 

 merged. It may be stated of a crop sown 

 in March 1880, that of the 164 days be- 

 tween spring and harvest, the fields were 

 inundated partially or entirely during ii? 

 days, and were kept dry during 52 days. 



The following were the periods of inun- 

 dation and dryness : 



OF INUNDATION : 



March 8 to 12, . . . 4 days 



" 20 to April 24, . 35 " 

 June 8 to August 20, . 73 " 



— 112 



OF DRYNESS : 



March 12 to March 24, . 8 days 

 44 " 



April 24 to June 8, 



52 

 164 



Total crop days, 



It will be observed from this statement 

 that the fields were dry between the 24th 

 of April and the 8th of June. During this 

 interval they are commonly hoed twice 

 and weeded before the succeeding inunda- 

 tion, called the " Harvest Flow," is applied. 

 Thus the soil is thoroughly stirred while 

 dry, except immediately under the plants. 



When the " Harvest Flow" is applied, it 

 remains until the grain is ready for the 

 harvest (hence the term "Harvest Flow"), 

 except to be occasionally discharged and 

 immediately renewed, according to the 

 judgment of the planter. As the water of 

 this flow is over the land in the hot months, 

 and as water at rest partakes very closely 

 of the temperature of the air, it presents 

 the characteristics favorable to putrescence, 

 if allowed to remain unchanged, especially 

 when lying over mold land. 



On the 13th of July the "maggot" was 

 found in fields which had been put under 

 the Harvest Flow on the iSth of June. 

 During this period the fields had been 

 twice emptied and fresh water supplied. 

 Indeed, this had been done only a few days 

 before the insects were found. 



These were discovered in their usual 

 primary habitats — in the lowest parts of the 

 fields, where the water was deepest, and 

 where the soil shows most mold. The 

 fields were immediately emptied, kept 



drained from two to four days, and the 

 water then restored. After this the worm 

 disappeared, and the plant, which had 

 betrayed their presence by dying leaves 

 and defective growth, regained its vigor. 



In this instance there was no putridity 

 in the soil or water when the maggot was 

 found ; but commonly, offensive soil and 

 water accompany its presence. Hence it 

 has become a question among rice planters, 

 whether the little worm called " maggot" is 

 properly a maggot of, or peculiar to, putres- 

 cence, or a predatory worm bred in the water 

 on the fields, regardless of its purity. 



The depredations of the maggot are al- 

 ways damaging to the crop in more or less 

 degree, especially as they affect during the 

 period of gestation, when the plant de- 

 mands the fullest use of its feeding organs. 

 Sometimes these depredations cause great 

 losses. Hence, if it is ascertained that the 

 worm is generated by putrescent conditions 

 in the water, the preventive method of 

 treating the fields is, obviously, the certain 

 remedy for the evil. 



It is now too late to furnish a plant 

 showing how and where the maggot attacks; 

 but it may be enough to state that they 

 assail and destroy the succulent roots of 

 the plant, and so incapacitate it for obtain- 

 ing food. 



NEW METHODS OF FIGHTING CERTAIN IN- 

 JURIOUS INSECTS. 



BY PROF. A. J. COOK,* LANSING, MICH. 



It is well known that there is no worse 

 pest to the pomologist than the Codling 

 Moth, {Carpocapsa pomonella, Linn.). The 

 great mischief done by this pest is aug- 

 mented from the fact that the best prevent- 

 ive hitherto known has been effective only 

 after the insect had done its evil work. We 

 have known no way to destroy the moths, 

 but could only capture and destroy the 

 larvse after the apples were eaten. Last 

 winter I learned from Mr. J. S. Woodward, 

 of Lockport, N. Y., that trees thoroughly 

 syringed with Paris Green, about the 20th 

 of May, bore apples which were wholly 



* Read before the Association for the Advancement of 

 Science, at the Boston Meeting. 



