Autumnal ramblings and spiders

Monday saw me out on Crowle Moors again, where despite the weather which was sunny and pleasant there was a noticeable change in the temperature and humidity.  This change certainly registered an autumnal feel to the visit.   A number of butterfly species were taking advantage of late flowering plants to nectar and the blackberries too were visited for their sugary juices.  Nettle-tap moths Anthophila fabriciana too were quite numerous with around 50 present on the last flowering heads of Tansy plants on the northern reserve.  A ubiquitous species whose larval food plant is the equally ubiquitous nettle Urtica dioica. 

130909 A marmoreus CM hrk 648

 

It was certainly an arachnid day, with thousands of silken strands strewn across the vegetation. The taller bracken supporting sheet webs with lines up from the lower vegetation.  What was particularly interesting was the number of female Araneus marmoreus var. pyramidatus (below) at various intervals around the Yorkshire Triangle.  There was also a beautifully coloured Araneus marmoreus  (above), the metallic ‘golden’ markings on the rich metallic green abdomen.  Other species such as A. quadratus and A. diadematus making the usual quartet of ‘big obvious’ jobs hoping to trap unwary insects in their webs.  Harvey et. al. (1999) in the Provisional Atlas of British Spiders describe it as uncommon (see also species summary on the BAS website), but the Humberhead Peatlands particularly the Thorne Moors complex hosts both colour variants.  For a more in depth discussion see Kirk & Howes (2011) in Volume 8 of the Thorne & Hatfield Moors Papers.

130909 A. m. pyramidatus hrk 638

 

Readers may recall I reported the Tansy Flask Gall   in early August.  It is now about a month later and the same plants showed more infestations, this time as the image below illustrates they are on the stem and not in the flower heads.  This plant has at least four areas affected with a number of growths in each.

 

130909 galled tansy CM hrk 659

 

Other galls still evident are the common picture-wing fly induced growth on creeping thistle Urophora cardui below.  The gall causing species is quite a distinctive fly, see here for some good images.

    130812 Urophora cardui CM hrk 544

So, what interesting observations have you made on the peatlands, do let us know. 

Click on the images to enlarge them to see more detail of the species illustrated.

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