80 



MISC. PUBLICATION 6 2 6, U. S. DEPT. OF AGRICULTURE 



Figure 134. — The bristly rose-slug 

 and its feeding injury. Slightly en- 

 larged. 



The rose-slug (Endelomyia aethiops 

 (F.)), formerly called the European rose 

 slug, skeletonizes rose leaves from the 

 upper side for its entire feeding period. 

 Its work (fig. 135) produces a char- 

 acteristic pale-greenish to yellowish, 

 chafed upper surface on the leaflets. 

 The larva is greenish, and when full- 

 grown is about }i inch long. This 

 species has only one generation a year, 

 passing the late summer, fall, and winter 

 in the ground in cells of cemented par- 

 ticles of sand and earth. 



The curled rose sawfly (Allantus 

 cinctus (L.)), sometimes referred to as 



Figure 135. 

 tonizing a 

 larged. 



-Rose-slug 

 rose leaf. 



larvae skele- 

 Slightly en- 



the coiled rose worm, eats the entire leaf 

 tissue, usually feeding from a curled 

 position (fig. 136) along the leaf edges. 

 The larva is greenish, with the sides 

 and legs grayish white, and about % inch 

 long. This sawfly has two generations 

 annually and spends the resting stage 

 in cells bored in pith, soft decayed 

 wood, or material of a similar texture. 

 When the pruned ends of rose shoots are 

 available it will bore into the pith. It 

 passes the winter in the pupal stage pro- 

 tected within its cell. 



Treatment. — Spray or dust with 

 lead arsenate, or dust with a lead 

 arsenate-sulfur mixture (p. 96) if dis- 

 eases are also involved. Nicotine sul- 

 fate and derris are effective against the 



^ 



Figure 136. — Larva of the curled rose 

 sawfly and its feeding injury. Slight- 

 ly enlarged. 



young larvae. Spraying or washing 

 the plant frequently with a stream of 

 water under pressure will wash off 

 many of the larvae. 



Prevention. — Clean up and burn all 

 rubbish in the garden to remove over- 

 wintering places for the bristly rose 

 slug. Work the soil to kill the pupae 

 of the rose-slug in the ground. For 

 the curled rose sawfly, paint the ends of 

 pruned twigs and remove pithy stems or 

 soft decaying wood that might serve as 

 places for pupation. 



Rose Leafhopper 



When rose leaves appear mottled, be- 

 come pale, and drop prematurely, the rose 

 leaf hopper (Typhlocyba rosae (L.)) may 

 be at work. The injury is done largely 

 by the nymphs sucking the plant juices 



