Willow Apple Gall Sawfly
( Pontania californica )


2010-0814-01080149-HYM00903-Pontania_californica[1205h40s,F,G,gall-tree-willow]{EXD}-G.jpg

PHOTO COMMENT

IDENTIFICATION
Identification:Pontania californica
(Marlatt, 1896)
Common Name:Willow Apple Gall Sawfly
Life Stage:(I) indeterminate/irrelevant

PHYLOGENY

Phylum:Arthropoda
Class:Insecta
Superorder:Holometabola
Order:Hymenoptera
Suborder:Symphyta
Family:Tenthredinidae
Subfamily:Nematinae
Genus:Pontania
Taxon Code:HYM00903

LOCATION DETAILS
Location
Sycamore Grove/Veteran's Park, Sycamore Grove/Veteran's Park, 5211 Arroyo Road , Livermore
County:Alameda County
ECI Site#:CA01080149

RECOGNITION
This sawfly makes the only round red/green willow leaf gall in California with lenticels (wartlike scales, tubercles). The gall protrudes on both sides of the leaf. Female - Length 5mm.; rather robust; clypeus broadly, circularly emarginate, lobes medium; frontal crest very strongly developed, broken; lateral walls of ocellar basin subobsolete; antennae with joint 3 very little longer than 4; sheath broad, not tapering, broadly rounded at tip; claws deeply cleft; venation normal, except that upper discal does not exceed teh lower. Color in general resinous; antennae, large spot on vertex, including ocelli, occiput, mesonotum, except scutellum, metanotum and basal segment of abdomen, lower half of mesepimera, and sheath brownish black; veins dark brown; stigma somewhat lighter basally; wings very slightly infuscated.
Body Length
5-6 mm.
Colors
Adult males are shiny black; females are dull reddish.

BIOLOGY
Host
Larva feeds on willow (Salix lasiolepis and Salix lemmonii)
Importance
Willow leaf gall sawflies apparently do not harm plants. Female sawflies insert their eggs in young willow leaves and inject a fluid that causes the formation of reddish, berrylike galls. One larva develops in each of these galls, which are globular or elongate and about 0.33 inch long. The larvae of several wasps, and at least one weevil and moth, feed on the sawfly larvae or on the gall tissue, causing the sawflies to die. A wasp, Eurytoma sp., appears especially important in controlling willow leaf gall sawfly populations in California.

HABITAT

CREDITS
Photographer
Eddie Dunbar

REFERENCES
  • Managing Pests in Gardens: Trees and Shrubs: Invertebrates: Willow Leaf Gall Sawfly. UC IPM
  • Howard, L. O. Revision of the Aphelininae of North America. USDA.


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