PestMedium Severity

Scale Insects

Including Melanaspis tenebricosa (Gloomy Scale) and Lepidosaphes ulmi (Oystershell Scale)

Small, immobile insects that attach to bark, twigs, and leaves, feeding by sucking plant juices. Adult females are oval, reddish-brown with waxy fringe along body margin. They remain stationary for most of their adult life after initial settling.

Peak Season: Cool temperatures favored, crawler stage in summer (July), overwintering in bark cracks, active development in spring
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Scale insect infestation showing characteristic oval brown scales on bark

Identification & Symptoms

What to Look For

Yellowing and premature drop of foliage
Honeydew excretion covering bark and leaves
Black sooty mold growing on honeydew deposits
Weakened trees susceptible to secondary problems
Heavy infestations can kill young trees outright
Reduced vigor in older trees making them vulnerable to other stresses

Potential Damage

Direct damage from sap removal weakening plants
Honeydew promotes sooty mold growth reducing photosynthesis
Young trees may be killed by heavy infestations
Older trees weakened and predisposed to borers and diseases
Increased susceptibility to drought stress
Reduced aesthetic value of ornamental plants

Lifecycle

Adults remain immobile after feeding begins. Eggs are deposited from spring to mid-summer, with peak laying in June. First instar nymphs (crawlers) hatch in July and migrate to rough bark cracks to overwinter. Active development and feeding occur in spring. Some species feed on leaves while others settle on twigs and small branches to feed.

Professional Treatment Approach

1

Crawler stage treatment for maximum effectiveness

2

Systemic insecticide application during active feeding periods

3

Horticultural oil applications during dormant season

4

Monitoring for crawler emergence timing

5

Targeted treatment of heavily infested areas

6

Professional assessment for species identification and timing

Recommended Mauget Products

Imicide

Professional-grade treatment specifically effective against scale insects.

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Abacide 2

Professional-grade treatment specifically effective against scale insects.

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Need Professional Diagnosis?

Our certified arborists can help you accurately identify tree problems and develop an effective treatment plan using Mauget's proven injection systems.

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