bearberry and manzanita galls

Member of galls

manzanita leafgall aphid
Tamalia coweni

manzanita leafgall aphid
Tamalia coweni

forms on midribs or edges of leaves of many species of bearberries and manzanitas (genus Arctostaphylos), including bearberry (Arctostaphylos uva-ursi), but not big berry manzanita (Arctostaphylos glauca)

galls cause significant swelling and distortion of the leaf edge
compare to Exobasidium arctostaphyli, which causes only a minor blister

big berry manzanita leafgall aphid
Tamalia glaucensis

big berry manzanita leafgall aphid
Tamalia glaucensis

forms on midribs or edges of big berry manzanita (Arctostaphylos glauca)

galls cause significant swelling and distortion of the leaf edge
compare to Exobasidium arctostaphyli, which causes only a minor blister

more info in this paper [HTML].

Exobasidium arctostaphyli

Exobasidium arctostaphyli

forms bright red blisters on the leaf surfaces of bearberries and manzanitas (genus Arctostaphylos), turning glaucous on the inner side

blisters cause only a minor buckling of the leaf surface
compare to ericaceous gall aphids (genus Tamalia), which cause signifant swelling and distortion of the leaf edge

see genus Exobasidium for discussion

Exobasidium a-spp-whole-shoot-discoloration

Exobasidium a-spp-whole-shoot-discoloration

discolors entire shoots (branch and all leaves) of bearberries and manzanitas (genus Arctostaphylos)
see genus Exobasidium for discussion

4 observed taxons / 1 key

Chris’s observations: 26 (12 are research grade)

Locations:

Ansel Adams Wilderness: 8
Rancho Cañada del Oro OSP: 3
Santa Teresa CP: 3
Castle Rock SP: 2
Mt. Madonna SP: 2
Almaden Quicksilver CP
Calero CP
El Sereno OSP
Lexington Reservoir CP
Mt. Diablo SP
Pulgas Ridge OSP
Skyline Ridge OSP
Waterdog Lake & Open Space

Months:

Apr.: 2
May: 5
Jun.: 4
Jul.: 2
Aug.: 0
Sep.: 8
Oct.: 0
Nov.: 1
Dec.: 2
Jan.: 2

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