146 
Clean culture seems to be of much importance, inasmuch as the 
eggs are deposited in fall on shepherd's-purse and possibly on various 
other weeds.* 
Fall plowing and burning over grassy and weedy areas in the 
neighborhood of potato fields are certainly to be recommended ; and 
Miss Patch further commends, as a precaution, the practice of burn- 
ing old potato stalks, since belated specimens of the plant-lice may 
possibly remain on them under certain conditions. 
SPINACH 
Spinach is often attacked in fall by a plant-louse which some- 
times destroys entire fields. 
The Omnivorous Plant-louse 
My::^iis pcvsica Sulz. 
{Rhopalosipliuni diantJu, Aphis dianthi) 
In the fall of 1908 my attention was attracted to the great abun- 
dance of a plant-louse infesting spinach on many truck-farms near 
Chicago. This louse may feed on almost any plant, as the common 
name above given implies. Among the vegetables which it sometimes 
injures, weakening the plants and causing a curling of the leaves, are 
turnip, radish, celery, cabbage, and cauliflower. It is impracticable 
to wash off these green lice after they become abundant, and the 
presence of thousands of them on the spinach renders it unsalable. 
Remedies. — The only practicable remedy is thoro spraying with 
a contact insecticide which will not give a permanent odor or taste 
to the leaves. The standard tobacco or nicotine extracts (page 154) 
answer the purpose. It is very important that spinach should be 
closely watched, and that the plants be sprayed at the first appear- 
ance of the lice. The treatment should be repeated at intervals as 
ma}^ be necessary. 
TOMATO 
Altho not extensively grown in the truck gardens of Cook county 
the tomato is of much importance in other parts of the state, partic- 
ularly as supplied to canneries. A stalk-borer (Papaipeina nitela) is 
the principal insect enemy of the crop in Cook county, and is no 
doubt the cause of more damage than is commonly charged to it. To 
the casual observer there is no indication of the presence of this in- 
sect when the plants wilt and die from its attack, and as a rule the 
gardener is at a loss to find the cause, the characteristic round hole 
in the stalk being easily overlooked. Occasionally the Colorado 
^According to Miss Edith M. Patch. See "The Potato Plant Louse." Bull. 
Maine Agr. Exper. Station, No. 147 (Nov., 1907), pp. 247-248. Orono, Me. 
