{82] REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
ask the question if it would pay to continue the business. By the end of the mouth 
of August every leaf was stripped from the plant as if a killing frost had fallen. 
After this, confidence was restored and cotton planted extensively until the year 1846, 
when again the crop was destroyed, The damage was considerable, and the yield 
lessened at least 25 per cent. After this no particular attention was paid to the worms 
until after the close of the late war, since which time they have reduced the yield 
year after year, until they became so destructive as to almost deter planters from en- 
gaging in the business. 
3. Iu order to answer this question intelligently I have obtained the following facts 
in regard to the appearance of the worm from the year 1867 up to and including this 
present year, 1879. 
Rain for the months of April, May, June, and July. 
Inches. 
1867 29^, 1>74 17/ 
1868 18^ : 1^75 7^ 
1869 1876 9& 
Inches. 
- 29A 
1874 
- i»A 
1875 
- 22-A- 
1876 
- W 
1877 
- »* 
1878 
1879 
- 23*8 
1870.... * 19/ 1877 20^ T 
1871 1878 15y 
1872 23^j 1879 16& 
1873. 
As to the temperature of the months of December, January. February, and March, 
Dr. F. Johnson says : "As to mean temperature of these same months, the variation 
is too little to have any influence on the question before you. Compare your notes on 
caterpillars, and see if you can find any mutual connection between lemperature, 
rains, and worms. T do not think there are any satisfactory bonds of connection." 
Caterpillars in — 
1867. — First appeared about 6th of June ; destroyed crop last of July. 
1868. — First appeared 1st day of May ; destroyed crop 10th of August. 
1869. — First appeared 20th of June; destroyed crop 20th of August, partially. 
1870. — First appeared 20th of June ; destroyed crop 20th of August. 
1871. — First appeared 15th of June : destroyed crop 20th of August. 
1872. — First appeared 20th of June ; destroyed crop 20th of August. 
1873. — First appeared 10th of June ; destroyed crop 1st of August. 
1874. — First appeared 20th of June ; destroyed crop 20th of August. 
1875. — First appeared 20th of June ; destroyed crop 20th of August. 
1876. — First appeared 20th of June ; destroyed crop last of August. 
1877. — First appeared 20th of June; destroyed crop 20th of August. 
1878. — First appeared 15th of June ; destroyed crop 25th of August. 
1879. — First appeared 20th of June ; did not destroy crop. 
4. This question is answered by the preceding answer so far as figures can, and 
from the statistics it appears that weather has no particular influence on them. You 
will observe that the months of April, May, June, and July of 1869 were among the 
wettest of the caterpillar years, yet the crop was only partially destroyed, and for the 
same months of the year 1876 we had nearly two-thirds less rain and the crop was 
destroyed as usual. As to their destruction by the ants, that will be more fully ex- 
plained later on. The plant during a dry spring is of very slow growth, and may not 
be able to furnish the necessary pabulum for the life and growth of the worm. This 
might be accounted one of the causes of a wet year favoring their development ; there 
is more surface and food for them in a wet spring than in a dry one. 
5. They have frequently been seen as early as the first days of the month of May, 
notably in the year 1868, when they appeared in great numbers in some localities, and 
did considerable damage to the cotton plant. Many planters were much alarmed at 
this early appearance, and thought themselves ruined again. The plant was, how- 
ever, yet young and recovered from the damage, and a pretty good crop was made. 
6. In the low moist places when the cotton is greenish and more tender. 
7. The insect undoubtedly passes the winter in the butterfly form, which is the 
fourth and last stage of their existence. They belong to the species Lepidoptera, and 
genus Papilio, and are the proceeds of the chrysalides from the caterpillars. They are 
about seven-eighths of an inch long, of a dark grayish color, not so pronounced on the 
under side of their wings, with a characteristic dark circular spot on each wing. The 
last seen of the caterpillar in the autumnal season, when the crop of cotton is destroyed, 
is in the form of the chrysalis, for after they eat all of the cotton leaves they proceed 
to " web up" on any leaf that will afford them protection. This chrysalis produces 
the butterfly, which immediately prepares for hibernation. It is my opi ion that they 
S( f;k winter quarters before they mingle in concourse with the males, hence their eggs 
are not fertilized until after they come from their torpid state in the .spring of the year. 
They may be seen in the warm days of January, February, or March, near the eaves of 
