Forms a tan wax cover or test up to 5.0 mm long; with a wax fringe around the margin and along the dorsal mid line. These fringes, particularly the dorsal ones, are easily rubbed off. Presence of the scale is usually noticeable because of the stunting, distortion, and discoloration of the terminal shoots of the host. Apparently a toxin is
injected into the plant which produces a "pitforming" response. The scales usually congregate on the growing tips and the overall effect is a severe distortion of tissue that often
obliterates the "pits" formed by individual scales.

Hosts: Prefers Pittosporum tobira and ceanothus, but has a long host list...

Economic Importance: This scale, probably native to Europe, causes serious distortion and death of the growing tips of ornamental hosts, particularly Pittosporum. Affected plants are severely weakened and unsightly. In central Europe, causes deformations on leaves and stems of English Ivy (Hedera helix) (Kosztarab, pers. comm.). The scale is regulated by quarantine laws in California, and nursery stock is required to be free of the insect. In an unusual instance in the State of Washington, this species caused up to a 50 percent loss in a commercial sugar beet field ...

Distribution: Found in most of the counties around San Francisco Bay. Also found in the San Joaquin Valley from Sacramento south to Kern County. Known from several western
states, the northeastern United States, and most of Europe.

Planchonia arabidis
Signoret, 1876
pittosporum pit scale
GALL
scale, attached to the stem in a low depression that is surrounded by a low ridge. Locally the stem is swollen and malformed... also leaves become disfigured ...

HOST PLANTS
polyphagous

Achillea millefolium, setacea; Aegonychon purpurocaeruleum; ?Alchemilla vulgaris; Alyssum montanum; Anthyllis vulneraria; Arabis collina, rosea; Bupleurum falcatum; Campanula garganica, glomerata, rapunculoides, rapunculus, trachelium; Capsella bursa-pastoris; Cardamine glauca; Centaurea scabiosa; Chenopodiastrum hybridum; Clinopodium acinos; Cota tinctoria; Echium vulgare; Epilobium palustre, roseum; Eupatorium cannabinum; Euphrasia; Falcaria vulgaris; Fragaria vesca; Gentianella ciliata, germanica; Geranium robertianum; Glaux maritima; Gypsophila fastigiata; Hedera helix; Helianthemum nummularium; Heracleum sphondylium; Hieracium; Holosteum umbellatum; Hylotelephium telephium; Hypericum perforatum, pulchrum; Inula ensifolia; Knautia arvensis; Lactuca serriola, viminea; Leontodon hispidus; Leucanthemum vulgare; Ligustrum vulgare; Linaria; Lithospermum officinale; Lotus corniculatus; Malva thuringiaca; Medicago falcata, lupulina; Melilotus dentatus; Nigella arvensis; Onobrychis arenaria; Origanum; Pastinca sativa; Picris hieracioides; Pimpinella saxifragae; Pittosporum tobira; Plantago lanceolata; Polygonum; Potentilla argentea, erecta, grandiflora, hirta, recta; Pulsatilla pratensis; Salvia x sylvestris, verticillata; Sanguisorba minor; Scabiosa ochroleuca; Scorzoneroides autumnalis; Scrophularia; Securigera varia; Seseli annuum, libanotis, osseum; Silene viscaria; Sisymbrium altissimum; Stachys officinalis, recta; Teucrium chamaedrys, scorodonia; Thesium humifusum, linophyllon subsp. montanum; Thymus serpyllum, vulgaris; Veronica chamaedrys, officinalis; Vicia disperma, tenuifolia.

[click below for photos]