Spruce Spider Mite
Attacks:
oaks, maples, ashes, and many other trees and shrubs
What you will see:
- Scale are initially flattened and brown in appearance
- Hardened and round when mature
- Tip dieback in branches
- Stunted chlorotic foliage
- Premature leaf drop and branch dieback
- Honeydew secretions on tops of branches
- Black sooty mold growth on honeydew
Life cycle:
- Overwinter as second instar nymphs on twigs
- Scales mature in spring
- Females lay eggs on twigs in May to June
- Crawlers hatch in June and July
- Crawlers migrate to the undersides of leaves to feed
- In late summer, crawlers migrate back to the twigs to overwinter
- One generation per year
Kermes Scale
Attacks:
White oak and several other oak species
What you will see:
- Adult females are approximately 1/4” in diameter
- Yellow to tannish-colored balls with specks
- Tip dieback in branches
- Stunted chlorotic foliage
- Premature leaf drop and branch dieback
- Honeydew secretions on tops of branches
- Black sooty mold growth on honeydew
Life cycle:
- Females develop on the twigs
- Males remain on the trunk and main branches
- Eggs are deposited in July and hatch in September
- Crawlers over-winter in cracks in bark
- One generation per year
European Elm Scale(Gossyparia spuria)
Attacks:
Elms and Hackberry
What you will see:
- Black lumps with white fuzz along the edges
- Many scales in one location
- Tip dieback in branches
- Stunted chlorotic foliage
- Premature leaf drop and branch dieback
- Honeydew secretions on tops of branches
- Black sooty mold growth on honeydew
Life cycle:
- Over-winter as second instar nymphs in bark crevices
- Females mature in late May, mate and begin laying eggs
- Crawlers appear in late June
- Egg hatch may extend through the end of July
- Crawlers feed on leaves throughout the summer
- Crawlers migrate to branches before the leaves drop in fall
- One generation per year
Magnolia Scale (Neolecanium cornuparvum)
Attacks:
Magnolia
What you will see:
- Big red and orange balls on the limbs
- Adult female can measure up to 13mm
- Small thin white scales all over green stem tissue (males)
- Tip dieback in branches
- Stunted chlorotic foliage
- Premature leaf drop and branch dieback
- Honeydew secretions on tops of branches
- Black sooty mold growth on honeydew
Life cycle:
- Overwinter as nymphs on one or two year old twigs
- Nymphs mature in late June through early August
- Males, small fly-like insects, emerge about the same time
- Males mate with females and then die
- Females give birth to live young, called crawlers, in late August or early September
- Crawlers over-winter on young twigs
- One generation per year in the Midwest
Fletcher Scale (Parthenolecanium fletcheri)
Attacks:
Yew, arborvitae, and juniper
What you will see:
- Big orange red balls on branches
- Dead foliage
- Honeydew
- Black sooty mold
- Adult scales at base of needles
- Thin plants with crusts of sooty mold covering twigs
Life cycle:
- Overwinter as second instar nymphs
- Adults on the twigs start laying eggs in late May
- Each female deposits 500—600 eggs
- Egg hatch in June into oval yellow nymphs (crawlers)
- Crawlers migrate a short distance to a new feeding site
- Crawlers remain on host plant
- One generation per growing season
Spruce Bud Scale (Physokermes picea)
Attacks:
Colorado, white, black, and Norway spruce
What you will see:
- Adult scales are globular and reddish to dark brown
- Located in clusters of 3 – 8 at the base of twigs
- Scales look like tree buds
- Lower branches are commonly infested
- Heavy infestations will kill lower branches
- Large amounts of honeydew on limbs below scales
- Black sooty mold on honeydew drenched branches
Life cycle:
- Overwinter as nymphs on under side of needles
- In the spring females move onto the twigs
- Nymphs mature to adults in April and May
- Egg are formed under the adult female scale
- Crawlers appear in mid June through early August
- Crawlers settle on new growth to begin feeding
- One generation per year
Cultural practices:
- Enhance growing environment with the Root Enhancement System® with Mature Prescription Organic Matter
- Fertilization should be low nitrogen
- Chemical treatments are effective to control this problem insect. Please consult with your Arborist for the best therapies.