Things That Go Bump In The Night

Rachel Wales ACR gets into the Halloween spirit…

As we approach Hallowe’en, we see lots of decorations featuring massive hairy spiders.  As I fished yet another beefy specimen of Tegenaria domestica out of my bathtub the other morning, I wonder if this is because late summer and autumn are the times when we humans start spotting, and screaming at, house spiders as they roam about our kitchens, bathrooms and sitting rooms in search of mates.  Autumn and spiders go hand in hand. 

I am not especially fond of spiders, because unexpected encounters with them do make me shriek, but I also hate finding them stuck in my pest traps here at Gloucestershire Archives*.  I put down sticky pest traps throughout our building, in offices, hallways and in our many strongrooms, and check them every three months.  But the purpose of these traps is not to manage creepy crawly populations by trapping and killing them; the purpose of the traps is to give me an idea of what types of invertebrates are in the building, and in what numbers.  And I am particularly concerned with finding species that pose a threat to our archival collections. 

A sticky trap in the archives

So, what creatures really do send shivers down my spine?  Here are two – spotted recently in a sticky trap in our Collections Care room. 

Varied carpet beetle larva and silverfish

This picture shows a larva of the varied carpet beetle Anthrenus verbasci (the larvae are commonly known as “woolly bears”), feasting on the corpse of a common silverfish Lepisma saccharina.  Super gruesome, right? 

Why are these insects considered to be pests?  It’s because they can potentially damage some of the materials found in archives.  In the case of the woolly bear, they are known to eat animal skins (such as parchment) and woollen textiles (such as the sample books from various woollen mills in Stroud, held here at the Archives).  Silverfish have broad culinary tastes, happily eating microscopic moulds, animal glue (used in bookbinding, and as a general adhesive) sugars and starches (such as adhesives used on old labels).  So you can understand why it would be alarming to find significant populations of either of these creatures in sticky traps. 

Any building is going to have insects and other invertebrates living in it – this is just a fact of life.  But part of our job here as Collections Care conservators is to establish what the “base line” for pest activity is in the building, monitor this base line for any upsurges in the population, and then to take action to control pest populations if we feel that our collections are in danger. 

And what about your home?  Are wool moths, silverfish or cluster flies making you break out in a cold sweat of rage and loathing?  If so, there are good resources out there to help.  You can try searching using the term “integrated pest management”.  This is the approach we take here at the Archives.  It’s about using a combination of cleaning, monitoring, and management of temperature and humidity to make our site as inhospitable to pests as we can manage.  I can also recommend a fairly new publication by UK pest experts David Pinniger and Dee Lauder, called Pests in Houses Great and Small.  It’s a great little book, with good photos and descriptions, useful case studies and practical advice on how to spot and deal with pests. 

Good luck with your pests, if you have any, and please wish me luck too as I undertake the autumn trap inspection routine and find out what has been going bump in the night at the Archives! 

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