APPENDIX I EEPOETS OF OBSEEVEES. 373 



fined to this bottom-land, though covering a much larger portion of it than the other 

 did, and being sufficiently numerous to have eaten the foliage from ten or fifteen acres 

 of cotton if it had not been poisoned. Similarly to what was found with the third 

 brood, this consisted of larvae of all ages, from the little one newly hatched to the 

 full-grown caterpillar webbing up preparatory to pupation, and with these were to be 

 found pupae, and imagines laying their eggs; -so that the fifth hrood really began in 

 small numbers at least a week earlier than the date presently to be given. This dif- 

 ference in age between individuals of the same hrood is at first sight a little puzzling, 

 and renders it very difficult to separate the later broods by any sharp-drawn line; 

 but when we consider that in the first brood I found a variation in age of nearly two 

 weeks the whole period of existence of a larva in the heat of summer and might 

 have found even a greater variation had I obtained more specimens, it is easily seen 

 that their descendants must show the same difference in age. 



By September 1, the larvae of the fifth brood, ''third crop" or " army," were appear- 

 ing in considerable numbers, and when I left the field two weeks later they were still 

 hatching in small numbers ; some eggs were yet being laid, while many larvae were 

 full grown, and some had already pupated. Unlike the second, third, and fourth 

 broods, but agreeing with the first, these larvae were not confined to wet places in the 

 swamps, but were almost equally abundant in the swamps and on the ridges, on cotton 

 growing in damp ground and on that growing in dry places. 



About the first of July, in a conversation with me, Professor Eiley said that he 

 believed the common idea that Aletia does better in wet than dry weather to be founded 

 in fact, and that the reason for it was that in wet weather Aletia suffers less from its 

 insect enemies than when it is dry. A few weeks later, when noting how the larvae 

 were attacked by ants on cotton where ants were very plentiful, I became convinced 

 that ants were among the most important of their natural enemies. About the same 

 time I noticed that there were very few ants on the cptton where most of the larvae 

 of the second and third broods the latter of which was then in its prime were found, 

 the ground being too wet for their nests, while wherever the ground was dry there 

 were myriads of them. From this I drew the following conclusions : The female moths 

 which survive the winter lay theireggsou cotton growiug on ridge or in swauip, accord- 

 ing as they hibernate near the one or the other. Of the first brood of larvae, those on 

 dry ground infested by ants are mostly killed by these little insects, while those on 

 ground too wet for the ants to live in comfortably stand a better chance for escaping. 

 Webbing up where they have passed their larval state, these appear in time as moths, 

 and, finding a sufficiency of food in the nectar secreted by the plants immediately 

 about them, they for the most part migrate little, but deposit their eggs close to 

 where they themselves were born ; and this explains the reason that the majority of the 

 second brood are found in wet places. In like manner, when the second brood appear 

 as moths, they will feed and lay their eggs near where they have passed their lives ; 

 which accounts for the limitation of the third brood. When this brood appear as 

 moths, being mujh more numerous than either of the earlier broods, they necessarily 

 spread a little more, this scattering being in a more or less perfect circle about the 

 spot which has thus far contained the larger number of caterpillars. The fourth brood 

 when about to oviposit is generally so large in numbers that if they were to lay their 

 eggs where have passed their lives there would not be food enough for their offspring, 

 especially as this brood is usually large enough to defoliate the cotton where they are 

 found. Therefore they scatter far and wide, laying their eggs on cotton miles from 

 any place where caterpillars have been previously noticed, and usually their offspring 

 are numerous enough to eat up the cotton in a very few days wherever they appear, 

 and to show no decrease from the attacks of the ants or any of their other enemies. 



When there is much rain, the dry, sandy soil becomes saturated with water, so as to 

 be almost a quicksand, and this, of course, injures the nests of the ants, interfering with 

 their visits to the nectar glands of the cotton-plants. I have noticed, too, that in rainy 

 weather comparatively few of any kind visit these glands. Rain, then, lessens the 

 liability of the caterpillars being attacked by ants and wasps, as well as other of 

 their enemies, which are driven to seek shelter, and this accounts sufficiently well for 

 their greater numbers in wet seasons. 



It is a common belief that the caterpillars never eat out cotton which grows in the shade 

 of trees or shrubbery. Though I looked at many shaded places in cotton-fields, about 

 September 15, when most of the cotton had been stripped of its leaves, I found about 

 as many places where the shade was no protection as where it was protective. Wher- 

 ever their proximity prevents the worms from eating cotton, I suspect that the trees 

 or bushes serve as lurking places for insectivorous birds. 



Among other traditions which I have in mind are the following: Some planters be- 

 lieve that they are certain to find caterpillars on their cotton wherever they see lace- 

 winged flies. It is needless to say that there is no connection between the two, the 

 lace-winged flies visiting the cotton everywhere in search of cotton aphides, near which 

 they lay their eggs, their larvae being the well-known aphis-lions. 



A few men believe that where the larger coffee-weed grows in a cotton-field the 



