THE STAG BEETLE J. T .
(Colchester Royal Grammar School) ONE of the best known of all insects is the Stag Beetle (Lucanus cervus (L.)). This is one of the largest and most impressive of the world's insects, and has been recognised since Roman times ; in fact its modern scientific name of Lucanus was first given to it by the Roman naturalist P. Nigidius Figulus. It was named in honour of Lucania, a district of Italy, one of the many regions where it is found. It is in fact widespread throughout almost all Europe and the adjacent parts of Asia. An indication of its fame is the fact that it has received a ränge of populär names in many countries, all the names in some way indicative of its impressive appearance—" Flying Bull", " Flying Stag", " Dragon ", " Horned Beast ", etc. Few insects are as variable as this one. The males are distinguished by the enormous jaws which give the insect its resemblance to a stag. This sex varies from 30 mm. to 70 mm. in length in this country, the real giants being found in Eastern Europe and Asia Minor where they may reach a length of over 90 mm. As well as simply varying in size, there is a great Variation in the development of the jaws (from 5 mm. to 38 mm.) with a corresponding Variation in the development of the head, the larger males acquiring great ridges for the insertion of the jaw muscles. So different are individual specimens that no fewer than forty-seven " species " have been described from Europe. Modern opinion tends to reduce these to three, of which only one is found in Britain. Yet even these three (L. cervus, L. orientalis, and L. tetraodon) may only be varieties of a single species, since although the males are reasonably distinct, the females are almost indistinguishable. The female Stage Beetle, appropriately known by the French as " la Grande Biche "—the Great Hind, is quite different from the male in shape—so much so that eighteenth Century authors believed it to be a separate species. The main difference lies in the absence of antler-like jaws, but it also differs in other body proportions such as the legs. Like the male it varies in size, but not so much—in this case from 25 mm.to 45 mm. in length. The eggs are laid in rotting wood. It is said that the preference is for Oak, but young stages have been found in very many different timbers. The larva is a C-shaped whitish creature, recalling an overgrown maggot, which in its life of four to five years grows
88 Transactions of the Suffolk
Vol. 13, Part 2
to a weight of some 15 gms. (adults rarely exceed 3 gms.). It feeds on the wood, boring large tunnels, and since the larvae are usually found in large numbers it can readily reduce a large tree stump to a fragile honeycomb of tunnels. It is nearly always found in association with the larvae of the Lesser Stag Beetle (DĂśrens parallelepipedus (L.)) of similar appearance and habits, but much smaller. It forms a cocoon of wood fragments to pupate, and the adult beetle is said to emerge in the autumn. It then remains in the wood until the following summer before becoming active. T h e Stag Beetle " season " is a short one, lasting about six weeks and having its peak in late June or early July. DĂźring this period anyone living in the right district will see numbers of the insects crawling laboriously across pavements or Aying around in the evenings. One curious Statement appears in nearly all books on the subject, namely that the males' jaws are almost useless Ornaments. Certainly they are not used for feeding, since the the beetle is a liquid feeder, but they are certainly effective weapons. T w o males kept together will almost immediately begin to fight and the jaws can puneture the body of an opponent, or if a good hold is taken, can even crush it. Though large males can give the human skin a painful bite, the female is even more effective at drawing blood. Perhaps it is that which causes so many to be needlessly killed under the impression that they are dangerous insects which must be (literally) stamped out. Yet the creature does no harm unless mishandled and is very useful in nature in removing dead wood. Admittedly this may be annoying if it is found in a gatepost, but one must remember that it would not be there if the wood were not rotting in the first place. One curious feature is the Stag Beetle's peculiar distribution. I n one district it may be completely absent, yet only a mile or so away it can be so common as to be found in large numbers every year. Consequently it is very difficult to find out its distribution with any accuracy. Its record in Essex is a good example. Naturalists have collected for many years in the northern part of the county and managed to find only six speeimens. Yet had they looked in the " r i g h t " places (S.W. Colchester or Boxted) they would have reported the insect as abundant. I have for instance personally examined some 400 speeimens taken in the Colchester district o\ er the past two years. For the last four years there has been a national survey of the distribution of the Stag Beetle, organised by the South London Natural History Society. This survey (Hall 1964) gives only two records for SufTolkâ€”Woodbridge (1952) and Woolverstone (1962). I have recently had records from Thorrington Street (1963), Brantham (1964) and Kersey (1964). How far into Suffolk does the insect extend ? Are there any other major concentrations, like that of Colchester, which are as yet unreported ?
The accompanying map shows all the records of the Stag Beetle known to me, arranged according to the latest date for each locality. A symbol is to be found in each 10 km. S q u a r e from which the beetle has been reported since the nineteenth Century. This map was compiled from many dozens of sources, published and unpublished, but the bulk of the data is to be found in Hall (1961 and 1964) and Clark (1964).
J. T . , 1964. 31 : 167.
T h e S t a g Beetle in N o r t h - E a s t Essex.
' ' > D - G - > 1961. T h e S t a g Beetle S u r v e y — F i r s t R e p o r t . London Nat. 4U : 80. Hall D . G . , 1964. D i s t r i b u t i o n of t h e S t a g Beetle in Britain. London Nat. 43 : 67.
Note. T h e S t a g Beetle has also been recorded in Suffolk f r o m 1942 ? " w a r ^ s " T a t Ipswich (E. A. Ellis), Felixstowe ( D . J. Carpenter), N a y l a n d (Eric K i r k b y ) , S t o u r area and D e d h a m — p l e n t i f u l in early J u l y ( D r C H S M n i n ^ ' } V e S t S t o w — 1 1 1 1 P e " e t of Little Owl (H. J. Boreham), H o i b r o o k f o u n d b TV,1VT7 y A n n e S e m m e n c e , aged eleven, confirmed by J . C . N . W . (See Suffolk Nat. Soc. Trans. X I : 4, 360). At A . G . M . M a r c h , 1947, t h e Rev. C. E. T o t t e n h a m showed Lucanus cervus, L . , " with tautological left leg " says C . M . in c o m m e n t . W e have p r o b a b l y m a n y m o r e , b u t for some years w e have h a d n o Recorder of Coleoptera, t h o u g h the Rev. C. E . T o t t e n h a m , M A of Cambridge, o u r m e m b e r since 1945, has always b e e n available to identify species. e h e s t e r G . D o u g h t y listed s o m e 300 Beetles for Suffolk in Trans. Vol I I and 230 additional species in Vol. I I I . HON.