HANDBOOK OX INSECT ENEMIES OF FLOWERS AND SHRUBS 77 



Their feeding causes infested growths 

 to become deformed (fig. 127) and later 

 to wither, turn brown, and die. The 

 bud stems often become crooked. As 

 the maggots grow they become tinged 

 with red. When fully developed they 

 are about M2 inch long, and at this time 

 they drop to the ground, which they 

 enter to pupate. The pupae of the last 

 generation overwinter in the soil. The 

 adult is a tiny two-winged fly, or midge, 

 about He inch long, yellowish, with the 

 head and fore part of the body tinged 

 with brown. 



Figure 127. — Young leaves and flower 

 buds of roses injured by maggots of 

 the rose midge. 



Treatment. — No entirely satisfac- 

 tory remedy has been developed, but 

 the following procedure will give some 

 control. On the first indication of injury, 

 rake the ground as level as possible to 

 the extent of the branch spread, and 

 then apply a mulch about % inch thick 

 of fresh tobacco dust (waste tobacco 

 that is finely ground) containing not 

 less than 0.75 percent of nicotine. Make 

 the application as even as possible so 

 that there will be no exposed spots; 

 otherwise the maggots will be able to 

 enter the soil and complete their develop- 

 ment. The surface of the mulch must 

 be kept fresh by raking lightly about 

 once a week and applying a thin dress- 

 ing of fresh tobacco dust. All new 

 growths should be examined frequently, 

 and if any are found infested, they 

 should be promptly removed and de- 

 stroyed, preferably by burning, and 

 should not be left on the ground. 



Prevention. — Plant only midge-free 

 plants and obtain stocks from sources 

 known to be free of this pest. 



Rose Curculio 



The rose curculio (Rhynchites bicolor 

 (F.)) is a bright-red weevil, or snout 

 beetle (fig. 128). with black legs and 

 snout, and only about % inch long. It 

 is widely distributed throughout the 

 United States. With the mouth parts 

 at the end of their beaks the beetles 

 eat holes in the unopened buds, 

 leaves, and flower stem of roses and 

 peonies. Many of the injured buds 

 fail to open, and those that do expand 

 are riddled with holes. The beetles 

 appear on rose bushes and peonies early 

 in June and are gone in August. The 

 eggs are laid in the buds and young rose 

 fruits, or "hips." These hatch in a 

 week or 10 days into white, legless 

 iirubs. which feed on the seeds until 

 full-grown. Later they enter the ground, 

 change to pupae, hibernate, and appear 

 as adults the following spring. There 

 is only one generation a year. 



Figure 128. — The rose curculio. 

 times natural size. 



Five 



Treatment. — Where only a few 

 weevils are present they may be jarred 

 into a pail of water and kerosene. When 

 they are numerous, spraying with lead 

 arsenate is recommended. 



Prevention. — Collect and burn all 

 rose fruits, or hips, soon after they have 

 formed, as these usually contain the 

 eggs. Since wild roses also are at- 

 tacked, the hips of any such plants 

 growing nearby should be collected and 

 destroyed before the end of August, 

 whenever practicable. Cultivation in 

 the late fall or early spring kills the 

 pupae in the soil. 



Rose Stem Borers 



Occasionally roses are attacked by 

 stem borers. These are of two kinds. 

 those which attack unpruned and un- 

 injured shoots and those which attack 



