Tamalia coweni

(Cockerell, 1905)

Manzanita leaf gall aphid, Fold-gall aphid

Tamalia coweni is a gall-inducing that forms leaf galls on manzanita (Arctostaphylos), primarily affecting glabrous manzanitas. The species produces two distinct gall types: midrib or margin leaf galls, which are common, and less frequent inflorescence galls. Multiple individuals occupy galls communally rather than maintaining solitary structures. The species serves as for the aphid Tamalia inquilina and as prey for specialized dipteran .

Tamalia coweni by (c) Ken-ichi Ueda, some rights reserved (CC BY). Used under a CC-BY license.

Tamalia coweni by (c) Henrik Kibak, some rights reserved (CC BY), uploaded by Henrik Kibak. Used under a CC-BY license.

2014-08-09-15.07.09 ZS PMax Tamalia coweni-1 (14684749138) by John Rusk from Berkeley, CA, United States of America. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Tamalia coweni: //təˈmɑːliə ˈkaʊəni//

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Identification

Distinguished from other Tamalia by its association with glabrous manzanita species and production of two gall types: leaf galls (midrib or margin) and occasional inflorescence galls. Distinguished from the Tamalia inquilina, which inhabits existing galls without inducing them. Distinguished from Tamalia glaucensis, which specifically induces galls on big-berry manzanita (Arctostaphylos glauca).

Images

Habitat

Galls on leaves and inflorescences of glabrous manzanita trees (Arctostaphylos ). Documented specifically on greenleaf manzanita (Arctostaphylos patula) in Shasta County, California, and on Arctostaphylos insularis.

Distribution

Pacific coast of North America, extending eastward to Nevada and Colorado. Documented collection sites in Shasta County, California.

Diet

Phloem sap of manzanita (Arctostaphylos).

Host Associations

Arctostaphylos patula - gall greenleaf manzanita; documented in Shasta County, California
Arctostaphylos insularis - gall documented for gall induction
Arctostaphylos species - gall most of glabrous manzanita

Life Cycle

Forms galls on plant tissues with communal occupation by multiple individuals. Meiotic system involves a univalent X .

Behavior

Induces galls on plant tissues; exhibits communal gall occupation where multiple females share gall structures. Coexists with other within galls, including two obligate predatory dipterans that partition the resource through different exploitation strategies.

Ecological Role

Gall inducer that creates microhabitats supporting diverse . Documented gall associates include 25 from eight arthropod orders. Serves as obligate for the Tamalia inquilina. Serves as prey for specialized dipteran Leucopis sp. and Heringia sp., which coexist through resource partitioning.

Similar Taxa

Tamalia inquilina that obligately inhabits galls induced by T. coweni without forming its own galls; genetically closely related but distinguished by lacking gall-inducing ability
Tamalia glaucensisRecently described that induces leaf galls specifically on big-berry manzanita (Arctostaphylos glauca), whereas T. coweni uses most glabrous manzanita species

More Details

Genetic differentiation

of T. coweni from different plants are very closely related to one another, with minimal genetic differentiation across host . This contrasts with its T. inquilina, which shows strong genetic differentiation among host plants.

Predator community

Two dipteran , Leucopis sp. and Heringia sp., are obligate predators of T. coweni within galls. Heringia sp. has lower rates (10.8%) but superior competitive ability. Leucopis sp. maintains higher infestation rates (41.4%) to compensate for poorer competitive ability.