Roses pests

Keeping to a strict rotation for vegetable crops (see also p.230) not only allows better use of nutrients, but also prevents the buildup of pests and pathogens in the soil. With perennial crops, such as roses, strawberries, apples, and pears, do not replant with the same species in the same place. New plants may fail to thrive due to high levels of host-specific pests or pathogens in the soil. The old established plants may have built up tolerance to these. 

Certain roses are less suited to organic gardening than others. Bush roses, such as the hybrid tea and floribunda (cluster-flowered) types, dislike competition at root level and so are often grown as a monocrop in a rose bed. They reguire ample spacing, dislike underplanting, and due to the fact they are grown en masse, tend to be more susceptible to pest and disease outbreaks. 

Mahli, CS. 2000. Timings of operations to control damage by rose-ringed parakeets to maturing sunflower crops and their relationship with sowing times. International Pest Control 42(31 86-88. 

Insects provide another difficulty. One of the axioms of entomology is that in the Northern Hemisphere, insect populations are larger and more varied in the eastern parts of a continental mass. In addition to its other problems, eastern viticulture must do constant battle against numerous voracious insect pests. The rose chafer regularly appears just in time to nip off inflorescences as they are about to flower. The Japanese beetle turns every leaf of a grapevine into a piece of lace, if allowed to. In the Tidewater sections of the lower part, nematode infestation can be so severe as to make viticulture almost impossible. 

Mendelsohn, M.L., T.C. Ellwanger, R.I. Rose, J.L. Kough and P.O. Hutton (1995). Registration of biologicals, in Biorational Pest Control Agents, Formulation and Delivery, F.R. Hall and J.W. Barry (Eds), American Chemical Society, Washington, DC, pp. 20-26. 

Drought-tolerant moss rose thrives in rocky soil or sand. It enjoys full sun, high temperatures, and good drainage. Pests and diseases are seldom a problem. 

Leaves wrinkled and discolored. Cause Aphids. Several kinds of aphids attack roses, often congregating on the stem tips just below the buds. Their feeding damages lea es and buds. See the opposite page for an illustration of the pests and their damage. For com ro s. see Leaves wrinkled and discolored" on ra e... 

Leaves skeletonized buds and flowers damaged. Causes Japanese beetles sawflies bristly rose slugs. Japanese beetle is an all-too-familiar pest of roses in the Northeast, attacking leaves, buds, and flowers. For an illustration of the pest and its damage, see the opposite page. For controls, see Leaves skeletonized on page 236. 

Rose sawfly, curled rose sawfly, and, most important, bristly rose slug, have sluglike larvae that skeletonize foliage. They are especially destructive early in the growing season. Spray leaves with insecticidal soap, or dust with pyrethrin to control severe infestations. Handpicking is effective, but be sure to wear gloves handling these pests can severely irritate your skin. 

Cause Beetles. Rose curculios are A", bright red, black-beaked insects for an illustration, see page 204. Rose leaf beetles are A", shiny, blue or green pests. Both of these insects bore into flower buds, preventing them from opening. If there are only a few pests, handpicking is the best control. Remove and destroy infested buds. For severe infestations, spray leaves and buds with pyrethrin. 

Flower buds and new shoots deformed or dead. Cause Rose midges. The white larvae of this tiny yellow-brown insect feed on flower buds and tender shoot growth, causing the injured parts to turn brown and die. See page 204 for an illustration of this pest and its damage. Cut off and destroy all infested buds to reduce future damage. 

Trunk bands can also prevent codling moths and other pests from crawling up the trunk in the first place. Apply bands of sticky coating to tree trunks and rose stems with a stick or paint stirrer remove debris and pests... 

Protection Offered Sulfur can be purchased alone or mixed with other insecticides and inorganic fungicides to control a wide variety of garden pests. Use sulfur as an insecticide to control insects and mites on fruit trees and citrus. You can also use sulfur as a protectant fungicide. It is effective against apple scab, brown rot of stone fruits, powdery mildews, rose black spot, rusts, and other plant diseases on many crops, including grapes, potatoes strawberries, and tomatoes. 

Hendry, J. A., Homer, R. F., Rose, F. L. and Walpole, A. L. (1951) Brit. J. Pharmacol., 6, 357. Himmelweit, F. (1956) The Collected Papers of Paul Ehrlich. Vol. 1. Pergamon Press, London. Jermy, T. (1967) Biological Control of Pests Damaging Crops (in Hungarian), Mezogazdasagi Kiado, Budapest. 

Weighton, D. M., Rose, I. D. G. and Wright, D. S. (1977) Proceedings British Crop Protection Conference, Pests and Diseases, Brighton, The Boots Co. Ltd., Nottingham 1, 25. 

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