[62] REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



and clear, dewy niglits during those months seem to protect the plantations against 

 the ravages of this insect. The Mexican farmers, aware of this fact, have given the 

 boll worm the name of " Chahuistle," which is an Indian word for cloudy, misty 

 weather. 



The damage caused by this worm on new lands is small; also on old lands where 

 the plant has been set wide apart, say from 8 to 9 feet. 



I therefore draw from these observations the following conclusions, viz: The larve 

 deposited by the moth on the ground remains there from eight to nine months, 

 the young worm appearing just at the time when the cotton plant throws out the 

 boUs. 



Plowing and thorough tilling should be a preventive against this worm. Sunny 

 weather destroys it. Setting the plants wide apart, at least G feet, would allow the 

 sun to heat the ground, and must be, in my opinion, beneficial. 



:>. The larger worm, or caterpillar (Anomis x}jUna) has made its appearance on this 

 coast three times during the last twenty years ; in 1866, in 1873, and again in 1878. It 

 is a dark-green looping worm, with white and black lines, and destroys the cotton 

 plant by devouring the leaves. It is as yet impossible for me to find out the origin 

 or even habits of this worm. I have investigated the supposed causes of its appear- 

 ance, but without success ; the farmers here have not the slightest idea about it. An 

 apparent coincidence between the appearance of this plague and overflooding of rivers 

 in the cotton regions should be mentioned here. 



September, lb65. High floods ; complete inundation of cotton lands. 



February, 1866. Appearance of the caterpillar in small numbers, not causing much 

 damage. 



September, 1872. Floods ; partial inundation of cotton lands ; high lands and ridges 

 in the valleys not flooded. 



February, 1873. Appearance of the plague and total destruction of cotton planta- 

 tions. 



September, 1878. High floods ; complete inundation of cotton-growing valleys. 



February, 1879. Partial plague ; small damage done by the caterpillar. 



4. In answer to question 4 I would refer to above statements. I draw from them 

 the opinion that the worm has not been imported into Mexico, but originates in the 

 cotton valleys in such seasons when the peculiar condition of the soil and climate 

 combine to favor the development of larves brought down by floods from the moun- 

 tain lands. 



The cotton lands in this vicinity are bounded on the west by the Pacific Ocean, on 

 the east by high mountains, la ''Sierra Madre;" on the north and south by dense 

 woods and tracts of uncultivated lands. These circumstances present a great many 

 obstacles to the flight of the cotton moth. The nearest cotton plantations, as well to 

 the northward as to the southward, are at a distance from Manzanillo of at least 100 

 miles. 



Cotton has been grown in the State of Colima for the last fifty years. It does not 

 grow wild, but, if abandoned, some plants grow up to good-sized trees, bearing fruit 

 regularly every year. 



6. The directions of iirevailing winds on this coast are the following, viz: January, 

 south and west ; February, west and northwest ; March, west and northwest ; April, 

 northwest; May, northwest; June, south and northwest ; July, south and west; Au- 

 gust, south and west ; September, south and west ; October, south and west ; Novem- 

 ber, south and west ; December, south and west. 



The northwest and west winds- blow generally during the day ; at night these winds 

 change to the north and northeast. 



I give the prevailing winds for the whole year, as our planting and picking seasons 

 here are diflerent from those in the United States. 



7. It is not possible for me at present to remit specimens of insects that attack the 

 cotton plant, but reserve myself the privilege to do so in February next — the time 

 when these difi'erent insects make their appearance here.* 



I am, sir, your obedient servant, 



AUGUSTUS MORRILL, 



United States Consul. 

 Hon. William Hunter, 



Second Assistant Secretary of State, Washington, D. C. 



No. 77.] Consulate of the United States, 



Mazatlan, December 3, 1879. 

 Sir : I beg to respectfully acknowledge receipt of communication dated October 13, 

 1879, inclosing a copy of a letter from the Chief of the Entomological Commission 

 addressed to the Honorable the Secretary of the Interior, under date of October 6, 1879, 



* No specimens received. — C. Y. R. 



