Phytobia cerasiferae

Family

Subfamily

Genus

Species

Phytobia cerasiferae (Kangas, 1955)

Mine

Larva feeding on the differentiating xylem. Eggs deposited in summer, with larvae over-wintering just beneath the bark; feeding commences the following spring, with larvae vacating the plant between May and June. Pupariation occurs either on the surface of the soil or just beneath, at a depth of 9-15 mm.

Host Plants

• Prunus

Confusion Species

N/A.

Recording Grade

2

National Status

Common.

Puparium

Pale, straw-coloured; 3.9-4.3 mm x 1.4-1.6 mm; posterior spiracles pale brown, each with three, equally separated, minute bulbs.

Adult

Head: frons broad, 2.15-2.45x as wide as eye, sometimes with minute inter-frontal setulae above lunule; orbits scarcely projecting above eye at level of ors, becoming more protruding at base of antennae, maximum width of projection is equal to diameter of palpus; usually 2 ors, 2-3 ori; orbital setulae reclinate, sparse; eye bare; gena rounded or with a distinct angle on lower edge; jowl (=parafacial below eye plus gena) 0.24-0.35x height of eye; lunule broad, lower than semi-circle; third antennal segment shorter than deep; arista almost bare; palpi and proboscis unmodified; labellum of proboscis with 11-12 pseudotracheae in each half.
Mesonotum: 3+1 dc; acr in 7-8 rows; prsc long, often with one or two pairs of acr behind; inner post-alar (ipa) and postsutural intra-alar (ia) well developed; in one Italian male, scutellum larger than normal, less narrowed at hind end, with the apical scutellars inserted much wider apart (most likely a teratology as genitalia are identical to all other males); no setulae detected on scutellum; mid tibia with one or two posterolateral setae, none on fore-tibia.
Wing: normal, hyaline; veins M₁ and M₃₊₄ weaker than R₂₊₃ and R₄₊₅; subcosta similar to Agromyzinae as in many Phytobia species; costa not reaching vein M₁, ending shortly after vein R₄₊₅ or fading away up to wing tip or slightly further towards M₁; ultimate section of vein M₄ 1.4-1.7x length of penultimate; length 2.74 mm (in smallest male) to 2.96 mm in male, 3.23-3.35 mm in female.
Colour: frons matt black; orbits and ocellar triangle weakly shining; lunule silvery-grey; all antennal segments black; mesonotum greyish-black; all pleura and legs black; calypter margin greyish, fringe dark brown to black.

Additional information

On 19 December 2023, John Deasy checked Blackthorn (Prunus spinosa) stems in his garden in West Cork, Ireland, and found the medullary spots of P. cerasiferae, representing the first known record for Ireland.

On 3 January 2024, Andrew Crory examined Blackthorn stems at Loughinisland, Co. Down, Northern Ireland and found the medullary spots and feeding tracks of P. cerasiferae. This is the first known record for Northern Ireland.

The species has also been recorded at 420m asl (Shropshire).