Notes and Observations 16 Part 5

NOTES AND

OBSERVATIONS

Cnephasia genitalana. A N E W LOCALITY IN SUFFOLK. While checking the genitalia of a series of specimens of Tortricidae that had been tentatively identified as dark forms of Cnephasia interjectana (Haworth), it was discovered that one of them was, in fact, Cnephasia genitalana Pierce and Metcalfe, 1915. This specimen, which was a male, was very dark greyish-fuscous with only the slightest suggestion of the paler markings. It was taken at light at Stradishall, Suffolk (Map ref. T L 7453) on lOth August, 1965.

This locality is about twenty miles south of Lakenheath, the only other known locality for this species in Suffolk. The specimen from Lakenheath was also of this dark form (E. C. PelhamClinton, personal communication). Other specimens of C. genitalana have probably been overlooked and identified as dark forms of more common species (e.g., C. stephensiana (Doubleday), C. interjectana (Haworth), and C. pasiuana (HĂźbner)) from which they can only be differentiated with certainty by inspection of the genitalia.

K. P. and V. A. BLAND, 63 Charterhall Grove, Edinburgh.

T H E " P I N M O U L D " , Phycomyces nitens.

Last autumn I found in the shrubbery in my garden here a clump of fungus (mould) which bore a remarkable likeness to a luminous human scalp. As it was new to me I sent it to Dr. E. A. Ellis for identification and he replied as follows: " I t is the largest of our 'pin' moulds, Phycomyces nitens (Agardh.) Kunze and it tends to develop on fatty substances, such as pieces of buttered bread thrown away by picknickers in the woods. T h e long a-septate hyphae have an almost metallic lustre, thus nitens, which I always think of as 'darkly gleaming' " .

Mr. F. W. Simpson of Ipswich Museum teils me that this mould is not recorded in Mayfield's Suffolk Moulds and Smut-Fungi (VI, II, 106-112).

DR. J. W. E. CORY, Bury St. Edmunds.

HERON (Ardea cinerea) EATING FRESHWATER MUSSEL (Anodonta cygnaea). Whilst fishing from a boat on Loudham Decoy Pond I saw a heron stab at something under the water, and the beak re-emerged with a freshwater mussel clamped in it nearly half-way from the tip and apparently held diagonally to the long axis of the shellfish. Then the bird took its catch on to the bank where it seemed to have placed the mollusc on the soft mud of the bank and then to deal it two or three hard dagger-like blows with its beak.

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Suffolk Natural History, Vol. 16, Part 5

Subsequently the heron raised, lowered and raised its head three or four times with beak fully closed and I assumed that it was swallowing pieces of the mussei. Shortly after taking this meal it then flew off downstream.

When returning the fishing boat to its mooring I went to the spot and found the remains of a freshwater mussei with most of one valve broken away, the hinge and umbo only remaining on that side. I have previously found shells of similar appearance beside Purdis Decoy Ponds, Ipswich and Thorpeness Mere.

M. A. HALL, Wickham Market.

FRESHWATER MUSSELS IN SWEFFLING. Until it was cleaned out fifteen years ago the pond in Baker's Hill, Sweffling contained a number of freshwater mussels (Anodonta) but the exact species was unfortunately never determined. When it was cleaned out the pond was drained completely but the owners, Messrs. Holden, were sufficiently interested to return a number of Anodonta to the water in order to maintain the stock. A diligent search in the summer of 1973 failed to reveal any mussels and further enquiries elicited the fact that all the fish had died and none had been returned when the pond was cleaned out. The first stage in the life cycle of Anodonta when it hatches from the fertilised egg in the gills of the female is known as a Glochidiutn: these are expelled through the exhalant syphon and in order to survive have to attach themselves to a fish where they encyst themselves, usually on the gills or fins. After a shorter or longer period theglochidium turns into a small mussei, breaks out of the cyst and falls to the bottom of the pond or river, there to grow and mature. No fish no young Anodonta.

Anodonta anatina is common in the River Aide from Rendham School to Stratford St. Andrew and probably throughout its length.

CRANBROOK, G t . G l e m h a m .

OTTER,

COYPU, AND FRESHWATER

MUSSELS AT ALDRINGHAM.

The River Hundred is a small stream which drains the area running from Clay Hills, Kelsale, through Knodishall and finally runs into the Mere at Thorpeness. The Iower reaches for the last threequarter mile or so above the Mere are slow running with a muddy bottom but from there upwards the gradient gets slightly steeper with stretches of sand or gravel at intervals. The reed beds in and above the Mere have always been a haunt of Otters and they were strictly preserved by the late Captain Ogilvie: even when the Otter population in England was at its lowest in the 1960s there was always a pair there. A litter was bred there in 1973

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and I saw one myself in February of 1974. T h e number of coypu in and above the Mere seems to have varied as it has elsewhere.

I have not seen one myself recently but have found their droppings on the banks of the slow running part of the river above the Mere.

There are very few signs of reeds being eaten so the numbers must be low at present.

In the autumn of 1973 on the bank of the slow running muddybottomed Stretch of the river above the Mere I found a small pile of broken shells of the Swan mussei Anodonta cygnaea, all of which were distinguished by having one valve much more damaged than the other. At intervals up to February, 1974, I found further collections of cygnaea shells, all similarly damaged. Otters, coypu, and brown rats are known to eat Anodonta, but I understand from Mr. A. E. Ellis that when coypu first invaded Hethersett Lake he found similar piles of Anodonta shells with one valve much more damaged than the other. It seems probable therefore that it was coypu which were eating the cygnaea.

I have seen two other types of damaged Anodonta shells on the riverbank: a single cygnaea with the hinge portion of both valves broken off and the animal removed leaving the two valves connected by dried tissue, and two others, one adult and one juvenile 40 mm. long, both of which had broken perforations on one valve. There was nothing to show how these were damaged. but Mrs. Nicole Duplaix-Hall reports (personal communication) that if Anodonta are given to Otters in captivity they almost invariably break them at the hinge.

Between my house and Aldringham Parrot the gradient is steeper and the river runs faster. In that Stretch there used to be many of the smaller Duck Mussei (A. anatina) but they are now difficult to find. I have seen no sign of these having been carried ashore to eat.

BRIGADIER D. REID, Leiston.

T U E RED SQUIRREL (Sciurus vulgaris) was reported during 1 9 7 3 from Fritton Lake, Herringfleet, Bramfield, Westleton, Weston (Derek Moore, Carlton Colville), from Barsham and Worlingham (A. E. Vine, Wereham), and from Campsea Ashe (Major Schreiber).

T H E GREY SQUIRREL ( S . carolinensis).

1 5 0 were reported killed in Higham, West Suffolk and smaller numbers in Dalham.

A. E.

VINE,

King's Lynn.