#Brown China-mark by Dick Shillaker
Meet Dick Shillaker, naturalist and freshwater surveyor!
Dick’s interest in natural history, especially things aquatic, started as a boy, pond dipping in Epping Forest and keeping tropical fish. He studied zoology at Aberdeen University and then conducted research into marine amphipods. Paid employment took him down other avenues but as retirement approached, he felt his way back into natural history by attending courses, especially on aquatic invertebrates. Dick has surveyed ponds for the Freshwater Habitats Trust and has an ongoing project surveying dew ponds on the Wolds, primarily for dragonflies, for the Yorkshire Wildlife Trust. He has also collaborated with Martin Roberts and Africa Gómez on various projects including documenting mass mortality of toads and the occurrence of non-native terrapins in East Yorkshire. Dick likes to visit sites that are not well-known wildlife hotspots and always has a camera ready for insects in hedgerows when walking his dogs. Dick enjoys the story aspect of Natural History and has contributed articles to The Naturalist. He recently joined the Editorial Board of The Naturalist.
1 Adult Brown China-mark moth
Dick’s chosen species is the Brown China-mark, Elophila nymphaeata, a large micromoth. It is fairly common and fairly widespread in Yorkshire, particularly around ponds, lakes and canals. Adults have a wingspan of 22-30mm and are mostly recorded flying in July and August. They are quite variable in appearance; some individuals are dark and dull-looking compared to others with distinctly patterned brown and white/cream wings. Females are larger and paler than males.
This is an unusual moth because its larva is aquatic, living primarily below the water surface. The larva is described as yellow with a brown head, and black-lined prothoracic plate with a blackish central blotch. Larvae are found particularly on the floating leaves of plants such as Broad-leaved Pondweed (Potamogeton natans), Frogbit (Hydrocharis morsus-ranae) and Water Lilies (eg Nymphaea spp.). This association with aquatic plants is apparent from the Greek origin of the moth’s current scientific name: Elophila (water-meadow loving) nymphaeata (water-lily). In older books, the moth can be named Nymphula nymphaeata or Hydrocampa nymphaeata.
2a. Larval case of Brown China-mark attached to underside of leaf of Broad-leaved Pondweed
The larva emerges from an egg laid on the underside of a leaf of an aquatic plant and, for a short period, feeds by mining into the plant. The larva then builds a case from one or two oval leaf cuttings. Accounts of the subsequent development of the larva, and pupation, differ slightly.The larval case can either be attached to the plant or free, allowing the larva to move carrying its case when feeding on its food plant. The larva does not have gills, and it is assumed that at first it obtains enough oxygen by diffusion from water. According to the freshwater biologist John Clegg, after several moults the larva develops hairs and lives under water in an air-filled case (hairs preventing water from entering the case). It has been proposed that air in the case is obtained from air spaces within the plant; presumably air could also be replenished when feeding at the water surface. Another author notes that the larva overwinters within a gelatinous cover inside its case. Pupation occurs in a silken cocoon attached to the plant (above water level according to John Clegg).
Dick has found larvae without dense hairs or gills, matching the description of the Brown China-mark, in cases c. 1cm long attached to the underside and upper surface of floating leaves of Broad-leaved Pondweed in a ditch in Hull. Cases attached to the upper surface were noted when the water level in the ditch had dropped considerably, with some leaves resting on damp mud.
2b. Larval case opened to show the larva
A video by John Walters is available of the adult Brown China-mark and its larva at a pond in Devon, https://www.youtube.com/watch?v=3pGFqUCZ4co. The video includes a female Apsilops ichneumon whose behaviour is suggestive of searching or investigating; notably, members of this genus parasitise the larvae of aquatic moths. Two species of Apsilops (cinctorius and aquaticus) have been reported from wetland sites in the south of the UK; neither is known to have been found in Yorkshire.
Worldwide about 0.5% of moth species, mostly within the family Crambidae, have an aquatic larval stage. The Brown China-mark is in this family, as are the four other UK aquatic moths (of which Dick is aware of). Details of their Yorkshire status (from the Yorkshire Moths website) and some notable features of their biology are given below.
Beautiful China-mark (Nymphula nitidulata) = N. stagnata: Scarce and local resident. Larva, with tufts of gills described as tracheal, lives in a water-filled case.
Ringed China-mark (Parapoynx stratiotata): Scarce and local resident. Larva has gills described as tracheal.
Small China-mark (Cataclysta lemnata): Uncommon and local resident. Larva, with probable blood gills, lives in a case of leaf fragments, mainly under duckweed.
3 Leaf of Broad-leaved Pondweed with oval holes. Each hole is considered to be due to a Brown China-mark larva cutting out a piece a leaf to construct a case. Note an apparent moth larval case on the edge of the leaf.
Water Veneer (Acentria ephemerella) = Acentropus niveus: Fairly common and fairly widespread. In addition to having an aquatic larva, there are two forms of adult females: a wingless water-living form and a winged form.
The curious may wonder why four species of moths in different genera are called China-marks. According to John Clegg the name comes from “the fancied resemblance of the markings on the wings of some of them to the potters’ marks inscribed on the bottom of good china.”
Recording and monitoring
The adult Brown China-mark will come to light traps. Adults can also be flushed from vegetation during the day by walking around ponds and other suitable aquatic locations. Oval holes at least c.1cm long in a floating leaf of Potamogeton are a good indication of the presence of larvae and are worthy of closer examination as this will identify sites where the moth is breeding. Generally, records are best submitted to your VC recorder directly rather than via an online recording scheme such as iRecord. A list of VC recorders for moths in Yorkshire can be found here: Butterflies and Moths.
Further information and acknowledgements
NEYEDC would like to thank Dick for his time and expertise in helping to create this blog.
Dick thanks John Walters for providing the fascinating video of the Brown China-mark moth, and Gavin Broad for answering questions about Apsilops. Dick also acknowledges the excellent freshwater invertebrate courses he attended which were run by Sharon and Peter Flint.
Information on the Brown China-mark and other UK aquatic moths:
Clegg J (1965) The Freshwater Life of the British Isles. Third edition. Wayside and Woodland Series. Frederick Warne & Co Ltd, London.
Majerus M (2002) Moths. The New Naturalist, HarperCollinsPublishers, London.
Miall L C (1895) The Natural History of Aquatic Insects. Macmillan and Co, London.
Smart B (2017) Micro-moth Field Tips. Lancashire & Cheshire Fauna Society, Rishton.
Information on ichneumon parasitoids (Apsilops spp) of aquatic moths
Hirayama T, Yoshida T, & Nagasaki O (2014) The life history and host-searching behaviour of the aquatic parasitoid wasp Apsilops japonicus (Hymenoptera: Ichneumonidae), a parasitoid of the aquatic moth Neoshoenobia testacealis (Lepidoptera: Crambidae). Journal of Natural History. 48, 15-16: 959-967.
Verheyde F, Hoekstra P, Libert P-N, Eijera H, De Ketelaere A, Vandaudenard T, Belgers D & Brosens E (2021) Two hundred and five ichneumonid wasps reported for the first time in Belgium and the Netherlands (Hymenoptera: Ichneumonidae). Belgian Journal of Entomology 122, 1–142.