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on deciduous oaks

gall

tiny (< 1 mm) orange-yellow aphids on the underside of a leaf; each causes a yellow necrotic spot at underside and upperside. Some animals deposit large numbers of shining yellow eggs in a double concentric circle.

secondary host plants

Fagaceae, narrowly monophagous

Quercus cerris, coccifera, frainetto, petraea, pubescens, robur.

notes

south-european species; records of Ph. quercus from more northern Europe most probably are erroneous.

references

Barbagallo, Binazzi, Pennacchio & Pollini (2011a), Barbagallo & Massimino Cocuzza (2014a), Barson & Carter (1972a), Blackman & Eastop (2014), Braggion (2013a), Buhr (1965a), Houard (1908a), Meliá Masiá (1986a), Redfern & Shirley (2011a), Roques, Cleary, Matsiakh & Eschem (2017a).