Bugs in the Plumbing

Earlier this year a PhD student working on a project in the Forestry Department for the Institut National de la Recherche Agronomique (INRA) posted a request on an entomology list server that I am a member of. He is studying whether the introduced Western Conifer Seed Bug Leptoglossus occidentalis has the potential to become a serious pest in Europe. His request was to those entomologists based in North America who could provide him with samples from the bug's native territory. He wanted to compare the DNA of these specimens to specimens collected in France, to determine exactly where the French ones had come from.

He received helpful responses from many of the list members based in the US and Canada. Several people said they had studied the species themselves and outlined their conclusions about its potential as an economic pest. It seemed that it was just considered a nuisance pest, as it has a habit of overwintering in domestic dwellings, but doesn't cause commercial damage, even in high value seed orchards (plantations where the crop is tree seeds for propogation).

Photo courtesy of Tim from Aigronne Valley Wildlife.

That is, until a Canadian scientist mentioned that she had written a paper about the bug's ability to pierce plastic plumbing pipe! Everyone was fascinated, and the Canadian entomologist provided a link to her paper so we could read all the details.

She was invited to study the bugs after a manufacturer of plastic plumbing pipes started getting reports of weeping pipes. From the beginning there was a suspicion that it was the bugs causing microscopic holes, as they were always present when this problem was reported and when examined under magnification it was clear that the holes were being made from the outside.

Photo courtesy of Tim from Aigronne Valley Wildlife

Bugs were collected and put in boxes with various sorts of plumbing materials. Examination of the material showed that they had attempted to pierce everything -- all types of plastic and even copper. However, the only material they were capable of actually getting all the way through and causing a hole that leaked was PEX, an elastic polyethelene. These PEX pipes are 2mm thick and come in several colours. The bugs were not attracted to one colour over another, and there is no indication that they can sense the water inside. It seems that they instinctively try to pierce everything under their feet.

So, if you discover mysteriously weeping pipes in your home, search for Western Conifer Seed Bugs inside. We've had them in our house, in the spare bedroom (which is alarmingly close to the small bathroom, as Tim pointed out to me when I emailed him to ask for the photos). The species is quite common now in France -- but don't worry too much, their pipe puncturing activities seem to be fairly rare.

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A la cuisine hier: Mussels, cooked in white wine with leeks, celery, garlic, parsley and thyme.

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Nature News: I've had an email from Carolyn, a contact in Amboise, who tells me she has just been involved in some hunt monitoring on the weekend. Apparently there was a battue (beat style hunt) of Cormorants planned on the Loire near Langeais. The League Pour la Protection des Oiseaux (LPO) got wind of this and arranged for its supporters to be prepared to be there and record the activities of the hunt. At the last minute, probably because there were going to be television cameras there, the hunt was cancelled. The LPO has sent a strongly worded letter to the Préfecture pointing out that the Loire is a nature reserve which acts as a wildlife highway and dormitory for all sorts of species, especially migrants. The high numbers of Cormorants in the area at the moment are due to birds that have nested in Scandinavia making their way back south for the winter. The nearest fish farm to Langeais is 11 km away, so there was no justification for the hunt, even if one disregards the fact that the species is protected. Carolyn clearly rather enjoyed the experience and said it "Ended up being a good chance to meet some interesting people and in a beautiful setting." UPDATE: Here is a link to the TVTours video of the event.

I attended yesterday's fungi foray in the Forêt de Preuilly (fortunately the weather calmed down during the afternoon and we weren't rained on or at risk of being squashed by falling trees). Once I've catalogued my photos I'll write a post about the outing.