The Lunar-spotted Pinion (Cosmia affinis Linn.) is a widespread species in Essex which is
sometimes common. The population has shown a slight decline in recent years. The closely
related White-spotted Pinion
(Cosmia diffinis Linn.) is a beautiful and striking looking moth. It has always been a less
common species, but has declined so that it is now seldom seen, being recorded from only eight
10 km. grid squares in the last 20 years. The lack of mature elms may be a factor.
Among the microlepidoptera there are many more species which feed exclusively on elm.
Several are leaf-miners, feeding on the green parenchyma between the surfaces of a leaf, and
these quite happily live on the hedgerow elms which still abound. Many of them are very
common, being well recorded throughout the length and breadth of the county.
The larval mines of Stigmella species can be distinguished by means of the following key
taken from A. M. Emmet in 'The Moths and Butterflies of Great Britain and Ireland' Vol. 1.
1. Mine an angular or sinuous gallery, traversing much of the leaf .... 2
- Mine compressed into gut-like arcs .... Stigmella viscerella (Stainton)
2. Early gallery with linear frass, later with the frass formation variable; larva green;
exit-hole on the underside of leaf..........S. ulmivora (Fologne)
- Gallery from its start with more or less dispersed frass; larva yellow; exit hole on
upperside of leaf................S. marginicolella (Stainton)
Mines of all these species can be found in September. S. marginicolella also has an earlier
brood of larvae in July. All are common throughout the county.
One further species makes a gallery mine: Buculatrix albedinella Zeller. Unlike the
Stigmella mines this makes two or three, sometimes four, short 'sidings', tracks off the side of
the main gallery free of frass and in the main mine the frass is linear leaving clear margins.
Another difference is that Bucculatrix larvae leave moulting cocoons on the surface of the leaf.
This is also common throughout Essex.
The next class of leaf miners make an inflated pocket in the leaf within which the larva feeds.
The two species Phyllonorycter schreberella (Fabr.) and P. tristrigella (Haw.) have similar
mines, but that of P. schreberella is circular or oval often crossing a vein and strongly inflated,
whereas P. tristrigella usually makes a long and narrow mine constructed between two veins.
The pupa of the first is dark brown and of the second pale brown. Both are double brooded with
mines in late July and October to May, giving adults in May and August. Both species are
common throughout the county.
Ypsolopha vitella (Linn.) is a species which normally feeds on elm, although it has also been
recorded on Beech. Its larva feeds in a loose spinning, preferring the fruits of elm, but it will
also eat the leaves, in May and June. The adult moth is quite often taken at light. This species
is generally distributed throughout the county but its numbers seem to have declined. At times
a melanic form of the moth is found.
There are two species of Coleophora whose case bearing larvae feed on elm and these are
locally common in Essex. C. badiipennella (Dup.) when full grown has a comparatively short
case (5-8 mm.) which the larva makes by cutting out a piece of leaf usually from the basal region.
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