The principal host of C. ohridella in Europe is the white-flowering horse-chestnut, Aesculus hippocastanum. This species is heavily damaged in all areas where the moth is established. Other Aesculus species vary in their susceptibility or resistance to C. ohridella (Table 1).
The sister species to A. hippocastanum, the Japanese horse-chestnut (A. turbinata), is also very susceptible to damage, but other Asian species (A. assamica, A. chinensis, A. indica) are resistant and are not damaged.
North American species (A. californica, A. flava, A. glabra, A. parviflora, A. pavia, A. sylvatica) vary in susceptibility, and their suitability as hosts is less clear. Generally, they show an intermediate level of susceptibility, between the European and Asian species.
Susceptibility or resistance to C. ohridella within the Aesculus genus is more closely related to the taxonomic divisions within the genus than to the geographic origin of the tree species, and shows no association with tree size, form and flower colour (Table 1).
|Species||Tree height (m)||Flower colour||Susceptibility to
C. ohridella *
|Section Aesculus||A. hippocastanum||25||white||+++|
|Section Pavia||A. flava||20-25||yellow-green||-- / +|
|A. glabra var. glabra||2–8 / 10–30||yellow-green||-- / ++|
|A. glabra var. sargentii||8||yellow-green||--|
|A. pavia||3–4 / 10–12||red||- / +|
|A. sylvatica||2||yellow||--- / +|
|Section Macrothyrsus||A. parviflora||3–5||white||---|
|Section Calothyrsus||A. assamica||25||white / pink||---|
|A. californica||4–6 / 15||white / pink||---|
|A. wilsonii||25||white||no data|
|Section Parryanae||A. parryi||1–6||cream-white||no data|
* Susceptibility scored as +++ highly susceptible; ++ susceptible; + slightly damaged; - resistant; -- moderately to highly resistant; --- highly resistant.
Aesculus x carnea
A number of hybrids between different Aesculus species are also grown in parks and gardens in the UK and Europe, and are available commercially (Table 2).
The most common of these is the red-flowering horse-chestnut A. x carnea, a cross between A. hippocastanum and A. pavia. This hybrid is highly resistant to C. ohridella. Eggs are laid on the leaves and these hatch, but the larvae die in the first or second instar just as they start to expand the mine within the leaf tissues. As a result, A. x carnea rarely suffers any significant damage from C. ohridella.
The majority of other Aesculus hybrids are derived from crosses between A. flava, A. glabra, A. pavia and A. sylvatica. Susceptibility to C. ohridella varies from moderately susceptible in A. x bushii to highly resistant in A. x neglecta (Table 2). Susceptibility shows no apparent relationship with hybrid form, height, flower colour or parentage.
|Hybrid||Parent species *||Flower colour||Susceptibility to
|A. x bushii Schneid.
(= A. x mississippiensis Sarg.)
|g x p||yellow/pink/red||++|
|A. + dallimorei Seally||h + f||white||+|
|A. x dupontii Sarg.||s x p||yellow||+|
|A. x glaucescens Sarg.||f x s||yellow-green||+|
|A. x plantierensis André||h x (h x p)||pink||+|
|A. x woelintzense Koehne
(= A. x wurlitzensis Koehne)
(f x p) x s
|A. x arnoldiana Sarg.||g x (f x p)||yellow||-|
|A. x hybrida DC||f x p||yellow/pink/red||-|
|A. x carnea Hayne||h x p||red||---|
|A. x neglecta Lindl.||f x s||reddish yellow||---|
|A. x marylandica Booth||g x f||yellow||no data|
|A. x mutabilis (Spach) Schelle||p x s||yellow / pink||no data|
* f = A. flava; g = A. glabra; h = A. hippocastanum; p = A. pavia; s = A. sylvatica.
C. ohridella has also been reported, on occasion, to damage Norway maple (Acer platanoides) and sycamore (Acer pseudoplatanus). However, mines have not been found on field maple (Acer campestre).
Straw, N.A. and Tilbury, C. (2006). Host plants of the horse-chestnut leaf-miner (Cameraria ohridella), and the rapid spread of the moth in the UK 2002–2005. Arboricultural Journal 29, 83–99.