Thursday, 9 July 2015

The Prattle of the Little Bighorns

The day after I photographed a couple of very colourful Longhorn Beetles at Gibside (the first I'd noted in years) I couldn't believe it when I found another at Far Pasture, similarly patterned, though duller, and a totally different species.


Pachytodes cerambyciformis (Speckled Longhorn)
Medium sized up to 12mm (though the one I saw was nearer 2cms) a mainly southern distribution,
localized in the north and east, the Derwent Valley seems to be a stronghold of the species in the NE.
Larvae typically develop in exposed roots of fallen trees, take 2 years to mature, and the beetles
fly from May-Aug and found on many plants, preferring hawthorn, umbellifers and buttercups
 

I don't know too much about the Longhorns, other than they can be quite spectacular so I've done a bit of googling.

In Britain we have over 60 species ranging in size from 3mm to 45mm, though some introduced species are even bigger. It is the lengthy antenna which gives them their name, often being close to or more than body length. A few are considered pests but in the main they are thought beneficial to woodland as most species larvae are found in dead wood or the stems and roots of plants like thistles. Woodpeckers are especially fond of the larvae, and can be seen pecking at dead timber to root them out.
It is the introduced species which are mainly regarded as pests, using live trees for their larval stage, and the impressively sized Asian Longhorn the most destructive of these.
The adults emerge late spring and despite their imposing presence are harmless and purely vegetarian, and can therefore be found in June and July feeding on nectar on flowering plants growing along woodland edges and rides, particularly hawthorn, dogwood, and flat-topped umbellifers like cow parsley and hogweed.

I knew I had some other Longhorn photos of a couple of very distinctive species and managed to find them after a bit of a battle, I hadn't realised it had been so many years since I took them but I eventually found them from way back in June 2007, taken (with the Krappy Kodak) very close together just like my latest batch :

Rhagium Mordax (Black-spotted Longhorn)
A great scientific name, my first Longhorn and discovered in my own
front garden in early June 2007
Up to 23mm long but quite short antennae compared to most species. Larvae found
in stumps and decaying trunks of broad-leaved trees in old woodland
take 2-3 years to develop, adults fly from June-Aug, often found
on dead wood. 

Leptura quadrifasciata (Four-banded Longhorn)
I remember this one well just a couple of weeks later on June 20th, as it almost crashed into my face
at the Octagon Pond at Gibside, then I quickly photographed it when it landed on the fence.
The literature says it reaches 2cms long, I remember it as the biggest beetle I've ever seen
at around 4 cms. It was an impressive beast.
Birchwood (dead) is favoured for larval development which takes 2-4 years. adults like umbellifers and brambles

Completing the line-up are the two differently marked but same species at Gibside on Monday :


Two versions of Rutpela maculata (Black and Yellow Longhorn)
Up to 20mm long they are common and conspicuous. Markings vary, they are very active flyers
and visit umbillifers, brambles and thistles.
Larvae found in dead and decaying wood of broadleaved trees and take 2-3 years to develop
 
 I'll be keeping an eye out for more, it's peak time for them now and they seem to love the cow parsley flowers by the sides of roads and paths (as do many other pollinating insects) so worth a quick inspection as you pass.

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