- Eggs: Females lay eggs in May which hatch in about 2 weeks.
- Larvae: Larvae are yellowish and about 1.5 millimetre in length.
- Adults: Adults attach themselves to the juniper and form a protective waxy scale or shell casing. Mature males are whitish and have an elongated body. Mature females may be white to brown in colour and 1.5 millimetres in diameter with a dark centre. Females overwinter inside the scale and lay eggs the following year.
- Yellow or browning needles: The plant’s needles may turn yellow or brown as the scale insects suck sap from the juniper, arborvitae, cedar, or cypress tree.
- Formation of scales on branches: Small, white, round or oval specks on twigs and foilage.
- Black sooty mould: Black, sooty mould often develops on honeydew found at the infestation site.
- Preventive tools:
- Avoid excess nitrogen in the soil, which may encourage rapid plant growth which attracts high populations of scales.
- Physical tools:
- Scrape the scale’s hard shell casing off of twigs and foliage.
- Prune and destroy severely infested limbs.
- Birds and some insects will eat scale larvae when populations are low.
- Least toxic chemical tools:
- Following label directions, apply Dormant Oil on larvae before shell casings develop (usually before mid-June)