REPORT OF H. G. HUBBARD. [13] 



matured leaves ; they are covered with caterpillars, and even more badly ragged than 

 those outside in the sun. 



Cases of apparently whimsical exemption from attack are sometimes met with. As. 

 for example two fields, separated only by the turn of a furrow, one of which is eaten 

 np to the last row and the other left untouched. In these, as well as in cases where 

 shade is found to exercise a protective influence, I am iuclined to suspect an explana- 

 tion will be found, as bas been suggested by others, in a difference in the nectar se- 

 cretion of the leaf glands, the moths being perhaps attracted to those plants where 

 the flow of nectar is greatest, and avoiding those where, from some cause, but little 

 is secreted. As to the laws which govern the secretion of nectar I know nothing. , 



The period of larval existence was, at Centreville, about nine days in July and ten 

 days in August. In vivaria in the house the time was extended to fourteen days in the 

 former and sixteen days in the latter month. The worms occupy nearly the whole of 

 one day in completing their webs or cocoons; the following day they change to pupje,. 

 which attain their full brown color before morning of the third day. 



The pupa, except in cases of accidental reversal, is invariably found with the head 

 towards the base of the leaf. The pupa state lasts from eight to eleven .days in July, 

 from seven to eight days in August. The warm, damp nights in August seemed to. 

 hasten their development. 



The moths begin to emerge from pupa soon after sunset, and continue to appear 

 during a great part of the night. In August, on cloudy days, large numbers disclosed 

 at 6.30 p. m. The period of existence in the imago stage is difficult to determine 

 with certainty. The males probably die soon after copulation. In the fourth and 

 fifth broods the life of the female is certainly not more than fifteen days. Under net- 

 ting in the field, they survived nine or ten days, laying eggs nightly during at least 

 half of this period, and dying without having deposited all their ova. I am inclined 

 to think the average life of a moth in freedom is about ten days. In vivaria, when 

 deprived of moisture, they invariably died in four or five days. By keeping the air in. 

 the breeding jar moist, and giving them fresh cotton leaves sprayed with water, their 

 life was prolonged in some cases eleven days. They drank greedily, lapping up with 

 their proboscis the artificial dew produced by an atomizer. I first observed copu- 

 lation in my breeding jars on August 7. The following is a transcript from my 

 notes of that date : 



At 6 o'clock this morning I found two Aletia moths in copulation ; they disclosed 

 last evening from pupae that I was handling. I watched them about fifteen minutes, 

 when they quietly separated. The male genitals were not much protruded. The 

 two terminal plumes clasped the body of the female on either side, but I was unable 

 to observe the position of the other parts. The male rested with wings horizontal in 

 the usual position, the female held the wings raised vertically, a position I have never 

 seen it assume. Neither sex made anymovement until they separated, when the male 

 genitals were retracted at once to the normal position. 



My next observation was on August 14, when I found two pairs in copulation at 4 

 a. m. On this occasion I watched my jars during the entire night, except between 

 the hours of 2 and 4 a. m., when I unfortunately fell asleep. On awaking at 4 a. m., 

 I found one pair in coitu in jar No. 9 and another pair in jar No. 11. Both contained 

 moths which had emerged from pupa three nights before (August 11). Evidently 

 copulation had been in progress some time, for they soon separated, when disturbed 

 by the fluttering of the other moths. Both sexes held the wings horizontal. As. 

 to the position of the genitalia nothing new could be made out! Many fertile eggs- 

 had been deposited in the same jar earlier in the night, and probably by moths that 

 had copulated during the first or second nights. My breeding jars have been under 

 observation at all hours up to 1 a, m., but copulation was never seen during this part 

 of the night. Up to August 14 my night work in the fields had never been continued' 

 later than 1 a. m., and consequently I had never seen copulation there. Subseqiiently 

 I made observations during the early morning hours, and on several occasions found 

 moths in coitu just before daybreak. The coupling ceased as soon as it became light. 



During the day it is the invariable habit of the moth on alighting to turn the head 

 downward. After dark and throughout the night, they retain indifferently any posi- 

 tion they may happen to take on coming to rest. At dawn, as the light increases, it 

 is a curious sight to see the moths, one after another, reverse their positions, and set- 

 tle themselves for their diurnal nap. Aletia does not appear to me to be greatly at- 

 tracted by light; on the contrary, the moths often seem to be repelled by it. In 

 carrying a lantern through the fields at night, an occasional specimen flew against 

 the glass, often, as it seemed to me, in anger. Multitudes, disturbed by the light, 

 flew up at my approach and vanished in the darkness overhead. So wary do they 

 become when a strong light falls upon them that observatioos of their habits by night 

 are rendered exceedingly difficult, and I never once succeeded in watching closely a 

 moth in the act of laying her eggs. Late in the season, when the moths roam far and 

 wide in search of fruit, many fly into lighted rooms through the open windows, show- 

 ing that for certain individuals light has some attraction. 



