HANDBOOK ON INSECT ENEMIES OF FLOWERS AND SHRUBS 31 



become stunted. The borers, which 

 are full-grown by June or July, are then 

 2 3 inch long, dull white, with a brown 

 head. They change to brown pupae in 

 a slight cocoon, and in midsummer the 

 adult clear-winged moths emerge and 

 soon thereafter lay their eggs. The 

 caterpillars pass the winter in the hosts. 

 Treatment. — Cut out and burn the 

 infested portions containing the borers, 

 or dig out the boring insects. 



Other Pests of Clematis 



Page 



Fall webworm 51 



Black blister beetle 7,20 



Tarnished plant bug 35 



COLEUS 



Mealybugs 



Several species of mealybugs occur on 

 coleus and many other garden plants, 

 but the citrus mealybug (Pseudococcus 

 citri (Risso)) and the long-tailed mealy- 

 bug (Pseudococcus adonidum (L.)) are 

 most commonly found (fig. 50). With 

 their sucking mouth parts they remove 

 the vital plant juices, causing a loss of 

 color, wilting, and death of the affected 

 parts, if they are not controlled. More- 

 over, mealybugs excrete copious quan- 

 tities of sticky honeydew, which may 

 coat the foliage. A black sooty mold 

 that grows in the honeydew spoils the 

 ornamental value of the plants. Mealy- 

 bugs in general feed on so many plants 

 and shrubs that it seems unnecessary to 

 list them here. However, they prefer 

 the more succulent plants like coleus, 

 ferns, geranium, heliotrope, lantana, 

 salvia, and ageratum that are used in 

 flower boxes or in borders. These in- 



Figure 50. — Mealybug adults: Upper, 

 long-tailed mealybug; lower, citrus 

 mealybug. About 2\{ times natural 

 size. 



Figure 51. — Citrus mealybugs on under 

 surface of leaf. About twice natural 



sects are usually found in clusters along 

 the veins on the under sides of leaves 

 (fig. 51) and in crevices at the base of 

 the leaf stems. Since they multiply 

 rapidly, all stages may be present at the 

 same time. Mealybugs are usual ly 

 brought into gardens by accidentally 

 setting out plants that are infested. 

 Ants usually aid in transferring them 

 from plant to plant, so that in a com- 

 paratively short time they become 

 generally distributed throughout a gar- 

 den. The ants are attracted by and 

 feed on the honeydew excreted by the 

 mealybugs. 



Mealybugs are only about }i inch long 

 when full-grown. They derive their 

 name from the fact that their oval or 

 elongate bodies are covered with a white, 

 waxy, or mealy excretion. This cover- 

 ing is peculiarly protective against spray 

 materials. The young, or nymphs, are 

 much like the adults except that they 

 are smaller and lack the mealy covering. 

 The males develop into small, winged, 

 midgelike adults, but are rarely seen. 



The female of the citrus mealybug 

 (fig. 50) is distinguished by its amber- 

 colored body and the short waxy fila- 

 ments along the margin. None of those 

 filaments are nearly as long as the body. 

 The eggs are laid in a cottony mass, 

 resembling a small puff of cotton. The 

 long-tailed mealybug (fig. 50) is a 

 smaller species, and the body is gray or 

 yellowish. In addition to the shorter 

 body filament, it has four long ones at 

 the hind end, forming a long tail. It 

 produces no egg mass, because the young 

 are born alive. 



Treatment.— The first step in the 

 control of all species of mealybugs is to 

 eliminate ants in and about the garden 



