83 
THE MELON PLANT-LOUSE. 
(Aphis cucumeris, n. sp.) 
Order HEMIPTERA. Family Apurpipa. 
{A minute, very sluggish, green or greenish-black insect, occurring in immense num- 
bers from spring to late summer upon the under sides of the leaves and also upon the 
roots of muskmelons, watermelons, cucumbers, squashes, and other cucurbitaceous 
plants, causing the leaves to curl and shrivel and lose their color, and greatly hindering 
the development of the plant. 
This plant-louse, coming from no one knows where, has done, 
during the last two years, widespread mischief to the plants which 
it attacks. It was first noticed in the Farmers’ Review for Septem- 
ber 2, 1880, by Dr. Cyrus Thomas, then State Entomologist of Illi- 
nois, who says : 
“There has been great complaint among our gardeners this sea- 
son in reference to a plant-louse that is doing much injury to the 
nutmeg and muskmelon vines, and also to the cucumber vines. In 
some instances they have almost entirely destroyed entire fields of 
vines.’ 
He does not say definitely to what part of the State his remarks 
have reference, but implies in another part of the article that he is 
writing of Southern [llinois. 
In i881, at Marengo, in Northern Illinois, where large fields of 
cucumbers are raised for the supply of a pickle factory, this louse oc- 
curred in great numbers, but disappeared before the end of the sea- 
son without doing any grave injury. It also appeared in numbers 
sufficient to attract attention upon muskmelons and watermelons in 
Central Illinois. Early in the spring of 1882 it made an overwhelm- 
ing attack in many localities upon both watermelons and muskmel- 
ons. In a garden at Normal, for example, it appeared upon the 
vines when they had run about six or seven feet, soon literally coy- 
ering and killing them, (the striped cucumber- beetle assisting to some 
extent in this work), and the ground was plowed up and planted to 
another crop. About the Ist of July it again attracted attention in 
large fields of cucumbers at Normal, spreading rapidly and arresting 
the growth of the worst infested plants. Where muskmelons and 
cucumbers grew together, the latter were comparatively little injured, 
but the melons were sometimes almost completely destroyed, the 
yield amounting in some cases to less than five per cent. of the 
crop; in fact, many of the hills in these fields did not run at all, 
