THE COLORADO EXPERIMENT STATION 
36 
3Ialva sp,, native. 
Taiisetvun balsaniifcra. 
Poppy, cultivated. 
Vinca sp. 
Vicia sp. 
Lupine, native wild pea. 
Sugar beet (Beta vulgaris). 
Cantaloupe (Melo sp.) 
Watermelon (Citrullus vulgaris). 
Native thistle (Carduus sp.) 
Clirysantliemuiu sp. 
Marsilea vestita. 
Golden glow (Rudbeckia sp.) 
Cactus (Opuntia sp.) 
OUT-OF-DOORS 
Trees upon which eggs are laid. 
Peach (Primus persica). 
Plum (Primus doniestica and T^ineri 
cana). 
Choke cherry (Primus Virgmiana). 
Prune (Prunus doniestica). 
Nectarine. 
Tame cherry (Prmius cerasus). 
Apricot (Pi’unus Armeniaca). 
Sand cherry (Prunus inelanocariia). 
SUMMER POOD PLANTS ONLY 
Cabbage (Brasslca oleracea). 
Cauliflower (Brassica oleracea). 
Rape (Brassica naiuis). 
Turnip (Brassisca Rapa). 
Potato (Solanuni tuberosum). 
Tulips (Tulipa sp.) 
Pansy (Viola tricolor). 
Pigweed (Chenopodium albmn). 
Radish (Raphanus sativus). 
Amarantiis sp. 
C benoixidiuni (Bonus-Hlpnricus.) 
^falvastrum coccineum. 
Wild mustard. 
Lepidium sp. 
Dock (Rumex sp.) 
Bursa Bursa-pastoris. 
Tomato (Lycopcrsicum esculentuni). 
-Water cress (Nasturtium officinale). 
Apple (Pyrus mains). 
Pear (Pjtus communis). 
Lilac (Syringa vulgaris). 
Castor bean (Ricinus communis). 
Morning glory (Convolnilus sp.), wild 
Hollyhock (Althaea rosea). 
Horseradish (Nasturtium armoracea). 
Innnitne plants —The following plants in the insectary were 
not infested: onion, beognia, oxalis, (four-leaved sorrel), and 
coleas. 
Apparently, the only reason why the above list of infested 
greenhouse plants is not larger is because there was not a larger 
list of plants growing in the greenhouse, at the time. It seems 
that this louse will feed upon almost any tender green foliage early 
in the spring, or late in the fall when most plants have died out and 
the lice are hard pressed for food. 
A plant louse like this that is able to spend the winter either 
upon trees in the egg stage or as a louse upon succulent vegetables 
that are somewhat protected from the extremes of low temperature, 
and with such a wide range of food plants, has a remarkable power 
to continue its existence in a locality where it has once been 
introduced. 
INJURIES 
When the peach trees bloom, this louse often attacks the blos¬ 
soms in numbers sufficient to blight them. After the fruit forms 
they sometimes attack the young peaches in sufficient numbers to 
cause them to wilt and drop. They also attack the leaves causing 
them to curl and turn yellow in color and, if the attack is very 
severe, many of the leaves drop. 
NATURAL ENEMIES 
This louse is attacked by a large number of insect enemies 
and it is probable that its severe struggle for existence with these 
