A heavy infestation will weaken the plant and heavily infested plants may drop leaves. 0000050022 00000 n 0000001991 00000 n If found, make plans for scale management. Damage—Heavy infestations of this insect can encrust entire branches and cause branch dieback and can kill plants. of oystershell scale, but this form of the insect is less common in the Rocky Mountain Region. The small insects attach themselves to bark and cause injury by sucking the tree's sap; this metabolic drain on the plant may kill a branch or the entire tree. Those races with two generations hatch in late May and again in late July to early August. The scale overwinters as eggs under the mother's covering. 0000011929 00000 n 0000577697 00000 n Of the shrubs, lilac is perhaps most frequently infested. 1) belongs to a group of insects called the armored, or hard scales. Insects in this group all have sucking mouthparts. It occurs throughout the United States and is more common in northern states than southern states. 0000116093 00000 n Recommended Steps to Control Oystershell Scale To control scale insects effectively and to limit damage, Horticultural Oil Insect Spray should be sprayed on the tree in late winter and again before spring bud break begins. 0000004258 00000 n Effective insecticides include insecticidal soap, horticultural oil, Sevin, permethrin, and others. You can try horticultural oil treatments or to smother the new generation of scale insects that will hatch from eggs hidden under the waxy scales formed by their mothers bodies. Within a week they are covered with a waxy scale covering that provides protection from most insecticides. Severely prune back heavily infested branches and protect new growth with insecticide applications. 0000580023 00000 n 0000057851 00000 n 0000048566 00000 n %PDF-1.4 %���� A tree that large is past the point where hand removal of the scale is possible or practical. 0000008272 00000 n Heavy infestations 0000048002 00000 n 0000003483 00000 n Natural Treatments for Elm and Oystershell Scale March 1st, 2017 The mere mention of the word scale conjures up images of layers of crust, disfiguring a tree with a thick blanket of life-sapping insects. There are several scale insects, such as calico scale, cottony maple scale, and oystershell scale, that can become pests on dogwood. 0000002968 00000 n Old scale shells will stay attached to the tree for several years before falling off. 0000079567 00000 n Pest description and damage The mature scale is approximately 0.125 inch long, hard-shelled, brownish or gray in color, and usually elongated and slightly curved like an oyster or mussel shell. Soft Scales (see photo gallery) Read and follow are pesticide label directions. �X��m+�Y/���� �Q�h endstream endobj 54 0 obj <>stream 0000047574 00000 n 0000052545 00000 n The oystershell scale is one of the most common armored scale insects that cause injury to shade trees and shrubs. Oystershell scale is pretty common on aspen in Wyoming. The oystershell scale, Lepidosaphes ulmi, is the most damaging scale insect present in Colorado. 0000049714 00000 n OYSTERSHELL SCALE Lee Townsend, Extension Entomologist Oystershell scale is a common armored scale that can infest more than 100 pl ant spec ies. This systemic insecticide is a neonicotinoid that moves rapidly from the soil into the tree. UNL web framework and quality assurance provided by the, Apply to the University of Nebraska–Lincoln, Give to the University of Nebraska–Lincoln, Institute of Agriculture and Natural Resources. Scale insects are a unique group, that look quite different from other insects. 0000212496 00000 n They insert their mouthparts into the plant, begin to suck sap and soon molt. 0000011818 00000 n The insect overwinters as an egg under its mother's shell. The dormant season is a good time to check plants for oystershell scale. 0000011998 00000 n 0000050390 00000 n 0000010501 00000 n 0000005107 00000 n This pest can be controlled with delayed-dormant sprays of oil or oil with an organophosphate insecticide. Oytstershell scale is caused by a scale insect, not a fungus. The best way to control oystershell scale is to apply an insecticide when the crawlers are present. The newly hatched scale insects are called crawlers. X��j[��8T�V��vJ���+�C��J$��1i�c�DZ��i��e�V`�^��9�Mi�� �9�h���;/���Տ���k�&�6��ouS�_}R�Jܒ�4Ma�#1�������� Oystershell scale Check now for evidence of last year's insects. UNL Backyard Farmer TeamDept. 42 0 obj <> endobj xref 42 69 0000000016 00000 n This species is so called because their armor resembles the shell of oysters. The insects are not obvious and can build up large numbers on trunks and twigs before being noticed. 0000006340 00000 n The presence of crawlers can sometimes be determined by sharply tapping an infested twig or branch over white paper. h�T�1K�`���kb�Em_:�����.-�Y��fDNJ[EA�N��V!�[�p����U���!wupF���࿬���i?��������g8*�,��S��)�Ԥ�Ʀ�Z�D��rIp`�TS��!�¹%���&f������5!��1^$nT����=����F��^���un?�?�_���n����������ۡf? Some races of oystershell scale have one generation per year, and others have two generations per year. Their drab, bark-like appearance makes Lepidosaphes ulmi. 0000002158 00000 n Management—Natural enemies are generally adequate to reduce populations of this insect. Control To control these insects, spray twigs, branches and stems with horticultural oil in the spring before the buds expand, March to early April. 0000009697 00000 n Under this covering is a sac- Oystershell eggs typically hatch in late May or early June and the active ‘crawlers’ that emerge move about to find new sites to feed. Barkis usually intact beneath a scale. Whenthe bump itself can be squashed it is likely to be some othertype of scale. The oystershell scale (Diaspididae Lepidosaphes ulmi) (Fig. 0000003862 00000 n These insects attach themselves to branches or leaves where they suck juices from the tree. These insects feed at this site until development is complete. Oystershell adults excrete a waxy cover that gives it is oyster-like appearance. Scale insects are very unusual little critters, classified in the order Hemiptera, which also includes insects such as aphids, leafhoppers, and cicadas. ���NE�k#�۪��F��{ܚv}�?uW7p�uw��S�h7���]}ntw�������ڗ��O����{�|]m|�6����w����w��oMψf��|l��� ����'�[o�L�o �t� endstream endobj 55 0 obj <>stream 0000005563 00000 n Oystershell Scale. 0000007603 00000 n From this point on, they will remain in the same spot for the rest of their lives. 0000047294 00000 n 0000115734 00000 n Branch and tree death may result from large scale infestations. It develops on the bark of trunks and limbs of a wide range of commonly grown deciduous trees and shrubs, including aspen, ash, cotoneaster, poplars, willow and lilac. 0000002830 00000 n 0000014730 00000 n Covers have a distinct oystershell shape. They are pale in color and smaller than a pinhead in size. 0000101458 00000 n Oystershell scale is an armored scale (its covering is a hardened waxy material). 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