LIBRARY 
-TATE Pi-ANi' BOAPf> 
E-524 
January 1941 
INSECT ENEMIES OF HOUSE PLANTS AND THEIR CONTROL 
By G 
V. Johnson, Division of Truck Crop and Garden 
Insect Investigations 
Plants in houses or window boxes often become infested with various 
insects or other pests. Some of these pests may attack the foliage chiefly, 
while others may affect only the underground parts. The ones most commonly 
found are mealybugs, scale insects, whiteflies, aphids, red spiders, thrips, 
fungus gnats, and earthworms. The object of this paper is to give brief 
descriptions of these pests, followed by suitable control measures. 
Mealybugs can be recognized by their general appearance, which is 
that of small objects that have been dusted with meal or flour. They are 
soft-bodied insects and move about very little. The eggs are placed in 
white cottony or fuzzy sacs, which are usually a little larger than a full- 
grown mealybug. The insects and egg sacs are usually found at first on the 
underside of the leaves along the midrib or in the crevices where the leaves 
join the stem of the plant. Mealybugs obtain their food by sucking the plant 
juices, and, when they are abundant, the plant soon has an unthrifty appear- 
ance and growth is retarded. Mealybugs attack many plants, but they are 
especially troublesome on such plants- as coleus, fuchsia, cactus, fern, 
begonia, croton, gardenia, geranium, orchid, poinsettia, citrus, ivy, 
ageratum, and dracaena. 
A scale i nsec t is characterized by the small shell-like covering or 
scale which covers its body. There are many forms, ranging from round or 
oval to somewhat rectangular, and one has the shape of an oystershell. In 
color these insects range from white to black, but browns and grays pre- 
dominate. They are most often found on the stems of plants, but they may 
feed on the leaves and fruit as well. Their damage to the plant is similar 
to that of mealybugs in that they obtain their food by sucking the plant 
juices. Heavy infestations may not only cause retardation in growth, but 
also the destruction of the plant. Scale insects attack a wide variety of 
plants, among which are palms, rubber plants, citrus, ivy, vinca, croton, 
and ferns. 
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