434 



Geranium, cyclamen and snapdragon plants are often seriously 

 damaged by Tarsonemus pallidus, Banks (pallid mite) [R.A.E., A^ 

 V 507, 576], but if the plants are well spaced the injury is less 

 serious. 



The lar^•ae of Euclea indetermina, Bdv. (rose slug-caterpillar) often 

 feed in nurseries on rose, apple, cherry, buttonball and other trees, 

 and plants. Eggs are deposited in July and hatch in nine days. The 

 mature larvae are found on the lower sides of the leaves in September.. 

 Hibernation occurs in the pupal stage among loose leaves on the 

 ground, and the adults emerge in July. Spraying with lead arsenate 

 kills the larvae. Hand-picking is sufficient for slight infestations,, 

 but a glove should be worn, as the larvae have irritating spines. 



Enlarged and swelling stems of Rosa rugosa indicate infestation 

 by Agrilus viridis, L. (rose stem-girdler). Eggs are laid singly in the 

 bark. The larvae enter the sap-wood, making spiral channels, over 

 which the swelling appears. Pupation occurs above the swelling,, 

 causing shallow splittings of the bark. The adults emerge in June 

 and July. This pest has been known to attack forest trees, the 

 larval period extending over two years. The only known remedial 

 measure is the cutting and burning of infested stems in the spring 

 and autumn. 



The life-history and control of Neocerata [Dasyneura) rlwdophaga,. 

 Coq. (rose midge) have already been noticed [R.A.E., A, vii, 211,. 

 321]. 



Various species of poplar and willow are attacked b}' Melalopha. 

 inclusa, Hb. (poplar leaf-tier). There are two generations a year,, 

 adults emerging in May- July and August-October. The caterpillars, 

 feed in colonies, eventually eating all the leaves, except the terminal 

 ones, which are pulled together as a shelter, in which the pupal 

 stage is passed. All leafy nests should be cut and destroyed, failing- 

 which spraying with 3 lb. lead ar.senate paste to 50 U.S. gals, water 

 is recommended. 



Phytomyza aquilegiae, Hardy (columbine leaf-miner) first appears, 

 in May. The female punctures and feeds on the leaf tissue, and 

 then deposits eggs on the lower sides of the leaves. They hatch 

 in a week, and the feeding larvae make mines in the leaves, and in 

 two weeks pass to the pupal stage, which lasts another two weeks^ 

 There are several generations, the last pupae over-wintering in the 

 ground. 



Several parasites attack this pest, but are not sufficient to control 

 the first brood. The ground about the plants should be cultivated 

 after the last pupation, or in spring before the flies appear. All 

 infested leaves should be removed and destroyed. 



Gar gar a genistae, F. (caragana tree-hopper) has been introduced 

 from Europe. It inhabits Caragana arbor escens, but causes little 

 damage in spite of its numbers. The over-wintering eggs hatch in 

 June, and the nymphal stages occupy about a month. The larvae 

 and adults are attended by ants, and being sluggish, are easily 

 capitured. 



Dichomeris marginellus, F. (juniper webworm) after several j'ears, 

 has reappeared in the north. The larvae are gregarious, and web up 

 the foliage of junipers, where they pupate ; they feed on the dead 

 as well as the healthy fohage. The adults appear in June. An 

 effective spray is 3 lb. lead arsenate paste, or H lb. powder, to, 

 50 U.S. gals, water. 



