Cypress tip moth
Western North America
Damage, symptoms and biology
The cypress tip moth can cause severe and highly visible damage (shoot tip dieback and foliar scorch) to infested trees. Damage commonly occurs on hedges and individual specimen trees in urban settings. Damage caused by early instar larvae (mined scale leaves) usually goes unnoticed. Late instar larvae hollow out entire shoot tips. Infested trees appear scorched from April until the new flush of growth masks the damage in June. The dead hollowed out twigs are easily broken off.
Mature larvae up to 6 mm long. Head and prothoracic shield pale brown. Body unmarked, pale yellowish green.
This species overwinters as a third-to fourth-instar larva. Larvae continue to feed on warm winter days. Larval feeding activity increases in early spring (March-April) as the weather warms. Once feeding is completed (early to mid-May) the larvae leave their mines and spin a white paper-like cocoon among the live or dead foliage.
The pupal stage lasts about two weeks. Adults emerge in June, mate and begin laying eggs. Males live 8 days on average and females 9.6. Up to 33 eggs (mean 15) are laid individually on green tips of twigs in late spring and early summer; eggs require an average of three weeks for incubation. Larvae tunnel into individual scale leaves mining 9-12 scales between summer and late winter. By early spring the larvae bore into shoots 0.3-2.0 cm from the tip and tunnel 0.5-2.5 cm down the shoot and occasionally into a lateral shoot. Four to six shoots may be affected in this way by each larva. Affected shoots become brown and die when vacated. The larval period lasts ten months.
This species occurs in south coastal British Columbia; it also occurs south to California and has recently become established in Britain.
Canadian Forest Service Publications
Diet and feeding behaviour
: Feeds on the leaves of plants.
- Endophytic: Lives within plant or tree tissue.
: Feeds on woody tissues (wood).
- Miner: Feeds inside the blade of a leaf, between the epidermal layers, or beneath the bark of plants, by first excavating a mine into these tissues.
Information on host(s)
Chinese juniper, Eastern white-cedar, Lawson cypress, Leyland cypress, Monterey cypress, Rocky Mountain juniper
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