SAWYER BEETLE AT IPSWICH GOLF CLUB

On the morning of the 23^rd July 2003, I was examining the contents of a Mercury Vapour moth traps put out overnight at Ipswich Golf Club, when, apart from numerous moths I spotted a very large and impressive beetle in the bottom of the trap. I recognised that it was of the longhorn group, but didn’t know the species. It looked very similar to a large, unidentified longhorn I had seen at the end of June while moth trapping in the south of France.

The beetle was about 4 cm long, but also quite broad. It was Sawyer Beetle very dark brown in colour, with slightly lighter brown wing cases. One of the most distinctive features was the antenna: they were quite long (half the length of the body) and appeared to be made up of a series of triangular segments. It was duly potted up to be identified and photographed later on. Upon checking in the Blitz Beetles guide, I identified it as Prionus coriarius, the Sawyer Beetle, the second largest British terrestrial beetle. The name comes from Prionus, a saw or sawyer referring to the serrated (toothed) antennae formation that is more pronounced in males than females. Coriarius refers to the leather-like appearance of the elytra.

This species, according to the literature, feeds as a larva in the moist roots and lower parts of dying and decaying oaks but is rarely found higher than a foot or so up in upright trunks. Fully-grown larvae are over 8 cm long and take three-four years to metamorphose. Adults emerge from May to October with the main eclosion period being mid-July and August. Exit holes of adults round the base of developmental sites resemble those of field mice and are about one inch in diameter. Adults are nocturnal appearing at dusk especially on hot sultry rainy evenings. They hide away by day although can be found resting on tree stumps etc in which they have developed. They are not nectar feeders like many longhorns, but are occasionally taken resting on flowers. They have been seen attracted to entomologists’ “sugar” and frequently occur at light.

This was also the same beetle I saw in France, again at light. This was the first time I had seen this species in 10 years of moth trapping both at the Golf Course and around Suffolk.

According to David Nash, it is a Nationally Notable A species. It is local and sometimes not uncommon but not known from Scotland or Ireland. There is only one old record fromVC26 and with records for VC25 centred upon Ipswich and an approximately 15 km radius thereof. David’s first specimen was taken at a lighted shop window on Barrack Corner, St Matthew's Street, Ipswich on 19^th August 1962 indicating that it was able to maintain itself at that time in the centre of Ipswich. Many specimens were also taken at dusk in mist nets in an IpswichPark several years ago.

As part of the management for another beetle at the site the Stag Beetle, dead and dying trees are retained, where it is safe enough to do so, providing habitat for the Sawyer beetle and other dead wood invertebrates.

Many thanks to David Nash for confirming my identification and for some of the information included in this account, particularly the information on local records.

Neil Sherman, Conservation Officer Ipswich Golf Club.