311 
quently found infesting the same plant at the same time, which, how- 
ever, doe* not indicate dimorphism. 
The same was again briefly described by Mr. Ash mead in the Flor- 
ida Dispatch (new series, vol. i, p. 241, July 7, 1882), under the name 
Aphis citrulli. with an account in the same paper for July 27, 1882, of 
its destructiveness to watermelons in Florida and Georgia. 
In 1883 Professor Forbes described and figured this species again in 
the Twelfth Report on the Noxious and Beneficial Insects of the State 
of Illinois, in an article on the "Melon Plant Louse n (pp. 83-91), under 
the name of Aphis cucumeris, stating that it had first been noticed by 
Prof. Cyrus Thomas in 1880, when it was reported to him as doing 
much damage to nutmeg niuskmelons and cucumber vines, and that in 
some instances it had almost entirely destroyed fields of vines in 
southern Illinois. 
It was reported by Professor Forbes as having made its appearance 
in 1881 in great numbers in the cucumber fields at Marengo in north- 
ern Illinois. He stated, however, that it disappeared before the end of 
the season without doing grave injury. It appeared again early in the 
spring of 1882 at Normal and in many other localities of Illinois in 
overwhelming numbers upon both watermelons and niuskmelons, so that 
vines six to seven feet long were literally covered and killed by it. By 
the first of July it again attracted attention in large fields of cucum- 
bers at Normal, spreading rapidly and arresting the growth of the worst- 
infested plants, though where niuskmelons and cucumbers grew together, 
the latter were comparatively uninjured, whereas the melons were 
sometimes completely destroyed. 
What will prove, no doubt, to be the same species, was again described 
by Prof. C. M. Weed in the Bulletin of the Ohio Agricultural Experi- 
ment Station (vol. n, no. 6, second series, no. 13, Sept., 1889, pp. 148-150), 
in an article on the Strawberry Root-louse" under the name of Aphis 
forbesi. In this article Mr. Weed cites an interesting observation on 
the habits of this species, published by Prof. S. A. Forbes in the 
Thirteenth Report of the State Entomologist of Illinois (pp. 102-103), 
as follows: 
In th6 latter part of September, 1882, an assistant, Mr. Garnian, observed upon 
strawberry plants near Centralia numerous clusters of dark-green plant-lice, gath- 
ered on the crowns and between the bases of the roots, at and just beneath the sur- 
face of the earth. In November they "were still found at the same place and in the 
same situation as before. They were all wingless and of various sizes, but most of 
them adults, actively engaged in oviposition; the eggs, some black, some yellow 
and freshly laid, being abundant among them. 
In some fields near Centralia half or two-thirds of the stools were occupied by 
them; but I was not able, at that late season, to estimate the damage due to them. 
No plant-lice of any species were seen upon the strawberry elsewhere in southern 
Illinois, nor have any been seen there since. Even in these very same fields not a 
louse of any sort was discovered the following May, at which time the plants were 
thoroughly searched for them. 
The same species was also found in the same situation upon plants near Normal, 
in the latter part of September, a fact showing the wide distribution of this form. 
