The Essex Naturalist
83
Flight
Many observers reported stag beetles in flight. This occurred mainly at dusk
between 21.00 hrs and 22.00 hrs from mid-June to early July, exceptions being a
female seen in flight at 15.00 hrs on 7th July and two individuals at 17.15 and
18.00 hrs on 9th July (a particularly dull day) and one at 18.00 on 10th July. In
some cases large aggregations of flying beetles were observed, for example, 40-50
seen flying together in Lexden at dusk. Three observers reported such mass flights
centred around large trees, an apple and a fir being identified as foci of activity.
Flight activity was linked with particularly warm evenings by several
observers, one also mentioning high humidity. Another observed that flying did
not occur on the very windy evening of June 11th.
Fighting
Fighting between male stag beetles is not often observed in the wild (Steggall,
1996) although many observers have found that males will fight readily in
confinement. A particularly graphic account of such behaviour is given by L.
Coffey :
"One male stag beetle was observed on a concrete driveway. He went to the
edge of the drive and another [male] emerged from a gap between the drive and
the house wall. They locked jaws on three separate occasions, after which one
retreated and the other disappeared under the concrete drive. After locking jaws
one stag beetle lifted the other up in its claws [sic], a cracking sound could
clearly be heard." The time was 13.00 on 30th June 1996.
On 10th July a male was seen to attack a pair attempting to mate.
Mating
Several observers witnessed the mating of stag beetles. The earliest date noted
was 17th June (a night of great stag beetle activity generally), mating was
observed at 21.45 by P. Wilson and elsewhere 20 were seen flying and mating in
mid-evening in the vicinity of an old stump. The last observation of mating was
July 14th.
Five cases of attempted necrophilia were observed, in most of these the female
had been crushed, perhaps causing the release of pheromones.
Breeding
The literature suggests that eggs are laid in rotting stumps and roots of a variety
of trees especially Ulmus (elm), Tilia (lime) and Fagus (beech) (Hyman &
Parsons, 1992). Whilst there were no actual observations of oviposition during
the present survey, several respondents noted apparent associations of beetles
with particular types of wood. In some cases larvae and pupae were found,
confirming that breeding had occurred.
Table 2 lists the tree species where evidence of breeding was recorded. As
there is a possibility of contusion with larvae of the lesser stag beetle Dorcus