LETTERS, NOTES AND QUERIES
Containing this month:
Segestria florentina in Felixstowe by Paul Lee
Puzzling Enquiries at Ipswich Museum by David Lampard
Segestria florentina in Felixstowe
The three species of Segestria known from the UK are all tube dwelling, nocturnal
spiders. They have six eyes, a tubular abdomen and the front three pairs of legs
longer than the last pair. These are adaptations to their normal hunting pose which is
to sit within the silken tube they have created in a cavity in a wall or under bark. The
front legs project from the tube and monitor silk strands radiating out from the mouth
of the web. If a passing insect activates one of these “trip wires” then the spider
rushes out to take its prey.
Segestria florentina is a large impressive spider that is
widespread in the countries of southern Europe but becomes
increasingly uncommon further north. In the UK it has only
been found in southern England, usually around port areas,
where it constructs its webs in cavities in the walls of
buildings. A female specimen of this spider was found in
November last year in Felixstowe when port workers were moving some wooden
pallets in a warehouse. As the pallets were supporting bags of cocoa beans the
workers were concerned they had found a potentially dangerous, tropical species.
They contacted Claydon based pest control company IGROX, who passed the spider
to me for identification. Despite its fearsome appearance, especially in the female
where the metallic green poison jaws are notable, the spider is harmless.
This is the first time Segestria florentina has been found in Suffolk and
Felixstowe is now the most northerly location in the UK from which it has been
reported. However, at this stage it is too early to say whether the spider is an
accidental import or whether a breeding colony is established in the town.
Paul Lee
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Puzzling Enquiries at Ipswich Museum
Beetle behaviour
Enquiries to the museum come from a number of sources. Last August Radio Suffolk
took a call from a person in Waldingfield near Sudbury who was concerned that the
side of his house was covered in small metallic brown beetles. A short while later
another caller reported the same phenomenon. Naturally they wanted an immediate
explanation of what sort of beetles they were and what they were doing. I suggested
that the beetles might be gathering on a wall that had absorbed heat to warm
themselves in the evening, which seemed plausible at the time. However, I was
unable to identify the beetles without seeing them.
Fortunately one of the callers sent me some samples and I was able to identify
them as ground beetles of the genus Amara. I am grateful to David Nash and Nigel
Cuming for identifying them specifically as A. montivaga. I believe this is a species
associated with houses and disturbed ground such as gardens. However, I have not
come across other reports of large numbers gathering on house walls. Has anyone
else seen anything like it? Can anyone suggest another reason, apart from gathering
for warmth, as to why they may be there?
Bedbugs
An observation that I have made over the last couple of years is an apparent
resurgence in numbers of the bed bug Cimex lectularius. I have had a number of
people to see me with bed bug bites, and the bed bugs to prove it. Anecdotally it
seems that a number of pesticides that were used to treat bed bugs are no longer
available. Talking to victims of bites also suggests that travelling through countries
where Cimex is prevalent and staying in low cost accommodation increases the
chance of picking up the eggs.
Weevils
Over the past few weeks there have been a number of enquirers who have found
small black beetles in their houses. All of the beetles appear to be grain weevils
Sitophilus. According to the identification guides these beetles feed within the
kernels of cereals and are specific to particular grains: S. Oryzae the rice weevil, S.
zeamais the maize weevil, and S. granaries in wheat. The species I have seen have
four orange patches on the elytra and are either S. oryzae or S. zeamais, yet,
according to the finders there are no grains present in their houses.
In one or two cases patient questioning about recent household additions
revealed the source was stuffed toys or small cushions where rice or another grain
was used as the filler. However, in most cases the source could not be traced. I
should be grateful for any further observations and suggestions as to where the
beetles may be coming from.
David Lampard
The photos below show bedbugs and both come from websites. The link below each photo will give extra information (for the non-squeamish!) ........ (Web Editor)
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for more information.