quite a lot of Spiny Restharrow, not yet in flower, but a surprise was to find a big patch of
Dyer's-greenweed as well. Those who knew the area from long ago said that the quality
of the open slopes had deteriorated through neglect leading to overgrowth of Bramble
thickets. It had been a warm and rewarding day.
In early July we went for a short week's break to the Isle of Wight. The chalk downland
was full of summer flowers, but much of the rest amazed me with its obvious wetness:
marsh plants, and ferns and bryophytes, were everywhere and abundant, because of the
rainfall. It made me appreciate all the more our relatively dry climate in Essex, where
rain rarely dampens a day outdoors in the summer months, except for this summer!
A small invasion of the crab spider Misumena vatia
Frederick Linehan 156 Eastbrook Drive, Rush Green, Romford, Essex RM7 OYU
Chaos, clamour and confusion, shattered the semi-rural tranquillity of Eastbrookend, a
remote environ of Dagenham containing The Chase Nature Reserve, when a Romford
Rumour, the local name for a Chinese Whisper, enhanced the killing power of the Yellow
Crab Spider Misumena vatia (see plate 6), so that any kitten or puppy in the area would
not be safe from its lethal bite.
Crab Spiders have a full range of movement, forwards, backwards and even sideways
and it is this unique ability that allows them to hunt and feed in a specialised way. They
do not construct webs to trap their prey, but position themselves inside white or yellow
flowers and wait until an insect lands. Then, they stealthily manoeuvre until their
unsuspecting quarry is encompassed by the spider's two front pairs of legs, very long and
with retaining bristles on the inner edges, and with the rear pairs of legs anchored to the
petal surface, they quickly clasp the prey and bite the neck area, injecting a fast acting
poison. The spindly 4mm male has a brown carapace and legs and with a buff coloured
abdomen. The 10mm female is a ferocious predator, being able to kill both Hive and the
much larger Bumble Bee. The Marbled White and the Meadow Brown butterflies are
also known victims of this spider. The stalking ability of tire female is much improved
by the fact that she is able, over the course of a few hours, to change her usual yellow
colour, to the colour of the flower she is resting on, a camouflage that makes them very
difficult to be seen, unless of course you are one of our keen sighted local children, who
located five in adjoining gardens, a very high number for such a small area. Both the
sightings and the lethalness of the venom grew in amount and intensity as word passed
through the community grapevine. The Rapid Response Unit from the local Police Station
was alerted, but fortunately stood down before he could unpadlock his bicycle from the
Station cycle stand, as neighbours were convinced of the harmlessness of the spider to
their pets and it soon became a Badge Of Honour to have had one found in your garden.
Some thought was given as to the cause of the sudden influx of Misumena into the area
Essex Field Club Newsletter No. 39, September 2002
5