Plant Parasites of Europe

leafminers, galls and fungi

Phytomyza gymnostoma

Phytomyza gymnostoma Loew, 1858

onion leaf miner

on Allium

Phytomyza gymnostoma on  Allium ampeloprasum

Allium ampeloprasum, Britain, Essex, Colchester 28.xii.2015 © Maria Fremlin

Phytomyza gymnostoma on Allium ampeloprasum


Phytomyza gymnostoma on Allium ampeloprasum

vacated puparium


Oviposition in a leaf axil; from there a corridor descends along the leaf inner side. Part of the length of the corridor is below the surface. Often several mines per plant. Most of the feeding punctures are arranged in lines, parallel to the leaf. Pupation takes place low in the the plant, near the leaf base. The brown puparia are situated within the mine. They can best be found by bending the outer leaves outwards, and inspecting their bases (Collins & Lole, 2005a).

host plants

Alliaceae, monophagous

Allium ampeloprasum, ascalonicum, cepa, sativum, schoenoprasum.


Larvae probably the entire summer and late summer.


BE not recorded (Fauna Europaea, 2008).

NE recorded (de Meijere, 1924a).

LUX not recorded (Fauna Europaea, 2008).

distribution within Europe

All of western Europe, with possible exception of the Balkan Peninsula (Fauna Europaea, 2008); recently also found in the UK (Rob Edmunds in litt.).


Larvae unusually large (5-8 mm); front spiraculum with 16-18 papillae, rear spiraculum with 30-34 (Seljak, 1998a).


Napomyza gymnostoma; Phytomyza algeciracensis Strobl, 1906l Agromyza phytomyzina (Hering, 1933); Ph. palpata Hendel, 1935; Ph. palpalis Hendel, 1936.


It has taken till 1988 before the host plant of the species became evident (Spencer, 1976a, 1990a). Since that year the species has manifested itself as a serious pest on various Allium species (Seljak, 1998a). It looks like the problem is expanding westwards. One case concerned a leek plot in Germany, just over the Dutch border (de Goffau, 2001a). Part of the damage is connected to feeding punctures that provide entrance to fungus infections, but the main problem is the presence of numerous larvae and puparia – up to 100 in a single leek plant (Billen, 1998a). The reason why this species so suddenly has turned into a serious pest is unclear.


Beuk (2002a), Billen (1998a), Černý (2011a), Černý, Andrade, Gonçalves & von Tschirnhaus (2018a), Černý & Merz (2007a), Černý & Vála (1999a), Ci̇velek, Çikman & Dursun (2008a), Civelek, Deeming & Önder (2000a), Collins & Lole (2005a), Coman & Rosca (2011a), Darvas, Skuhravá & Andersen (2000a), Doorman (1962a), Gil Ortiz (2009a), de Goffau (2001a), Hering (1933c), Kahanpää (2014a), Lingbeek, Roberts, Elkner, ao (2021a), Martinez (1984a), de Meijere (1924a, 1937a, 1939a), Mesic, Dupor & Igrc Barcic (2009a), Pakalniškis (1994a), Seljak (1998a, 1999a), Simoglou, Roditakis, Martinez & Roditakis (2008a), Spencer (1972b, 1976a, 1990a), von Tschirnhaus (1999a), Zandigiacomo & dalla Montà (2002a).

Last modified 20.v.2023