172 APPLIED ENTOMOLOGY 



to the temperature, before becoming adult. When cabbage, cauhflower, 

 kale, turnip, radish, etc., become available, the bugs go to these and there- 

 after devote their attention to these plants until late in the fall when 

 various other kinds, such as egg plant, asparagus, tomato, beans, beets, 

 etc., may be attacked. 



Control. — Insecticides which do not injure the plants the bugs are on, 

 are not usually effective against this pest and preventive methods have 

 thus far given the best results. Planting a very early crop of kale, 

 mustard or rape, to which the bugs when they first become active in 

 spring may be attracted, is a good practice, for the insects seem to prefer 

 these to the other plants. Here the bugs may be killed by spraying with 

 kerosene, collected in nets and destroyed, or may be burned with a torch. 

 The few that may escape this treatment can be picked by hand wherever 

 found, but if the trapping method above is followed, few usually escape. 



Clean culture is also helpful. As soon as the crops are gathered all 

 the stalks and leaves of the plants on which the Harlequin bug feeds 

 should be gathered and destroyed, both to leave them no food and to 

 remove possible places where they might winter. Rubbish which might 

 provide wintering quarters should also be carefully removed. Recent 

 tests with contact insecticides show some possibility that control by 

 these materials may be obtained, but this subject has not yet been suffi- 

 ciently investigated to warrant definite recommendations. 



Family Cydnidae. — The bugs of this family are usually of little eco- 

 nomic importance. Some of them are interesting, however, as in them the 

 scutellum, usually quite small, becomes greatly enlarged, covering nearly 

 all of the thorax and abdomen behind the pronotum. In one genus the 

 insects are nearly circular in outline, very convex, having much the form 

 of lady beetles, and are generally glistening black, in a few cases with a 

 narrow line of white. These are often called "negro-bugs" and one 

 species feeds on small fruits and leaves a disagreeable odor. 



Family Coreidae. — Many of the members of this large family are of 

 considerable size for bugs, some being over an inch long, but their bodies 

 are much more narrow in proportion to their length than in the Penta- 

 tomidse. Some of the southern species have broad, flat expansions of the 

 tibiae, giving them a curious appearance. The insects of this group suck 

 plant juices and a number are frequently more or less injurious to various 

 plants. 



The Squash Bug {Anasa tristis De G.). — The Squash Bug is common 

 almost everywhere in the United States feeding on squash and pumpkin 

 and sometimes on cucumber and melon plants (see Fig. 161). The adult 

 is a dark brown bug, very finely mottled with gray or lighter brown in 

 many cases, about three-quarters of an inch long. It winters as the 

 adult under rubbish or in other protected places, and appears in spring, 

 ready for its food plants when these come up. When the leaves of the 



