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Willow Bean Gall Sawfly



P_wllowbngallsfly

Willow Bean Gall Sawfly

Usually appear in

Spring to Autumn.


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Caused By:-     Several species of Pontania Sawflies

Description

Gall on Arroyo willow (Salix lasiolepis) induced by a sawfly (Pontania californica syn. Pontania pacifica). Several species of sawflies of the Pontania genera causes bean galls in willow leaves. Adults sawflies emerge in late spring and females lay eggs into the leaf tissue. This stimulates the formation of hard yellowish-green to red kidney shaped galls to appear in the leaves in the Summer. The galls occur on both sides of the leaf, which are then eaten, from the inside, by the larvae when it emerges. In mid summer the larva leaves the gall to drop to the ground where it pupates. A second brood emerges in late summer, which overwinter as pupae. Usually there are two generations per year. Picture from Wikimedia Commons.
See also these other Galls ACER GALL MITES, ACORN GALL MITES, AZELAE GALL, BEECH GALL MIDGE, BLACKCURRANT GALL MIDGE, BROOM GALL MIDGE, CAMELLIA GALL, CROWN GALL, EUONOMUS GALL, FELT GALL MITES, FORSYTHIA GALL, GALLS, GALL WASP, GLEDITSIA POD GALL MIDGE, HEMEROCALLIS GALL MIDGE, HAWTHORN BUTTON TOP GALL MIDGE, KNOPPER GALL OF ACORNS, LEAFY GALL, LIME NAIL GALL MITE, OAK GALL WASP, PEAR LEAF BLISTER MITE, PINAPPLE GALL ALDELGID, PLUM GALL MIDGE, ROBINS PINCUSHION, VINE ERINOSE GALL MITE, VIOLET GALL MIDGE, TURNIP GALL WEEVIL.


Control

In general these galls do not do serious damage to the Willow and can be ignored, but they are sometimes disfiguring to the looks of the tree. In which case spraying with a systemic insecticide in early spring when the leaves are appearing and again in summer may prevent an attack. In winter soaking the soil with soil insecticide may kill the overwintering pupae.



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