Of gall bladders and other things

Today, 25 September, is sunny and dry.  Normally I wouldn't comment on this but so far the month has been rather cold and wet so I was glad of this opportunity to go for a stroll.

As already mentioned, the leaves of deciduous trees are showing wear and tear, largely as a consequence of the nibbling and boring of insects. Having said that, the first invertebrate on foliage to catch my eye was a harvestman, clambering through oak.

Harvestman with a mite. Kentle Wood. Daventry
25 September, 2015

As is often the case, this specimen was carrying a mite, seen as a red spot near the base of a leg. Some creatures such as mites and false-scorpions often 'hitch a lift' on an 
insect or other invertebrate as a means of getting from place to place. This is a phenomenon known as phoresy, but in this instance the mite is a parasite, and it is there to feed. The harvestman is Phalangium opilio, commonly found in low trees.

The pupal case of the Tipped Oak Case-bearer.
Kentle Wood, Daventry, 25 September, 2015

A curious structure on a nearby leaf had been formed by a micro-moth, the Tipped Oak Case-bearer, Coleophora flavipennella. The larva produces this case in which to pupate. The adult moth (imago) is confined to the south and east of Britain - and is, I'm afraid, very dull.

A Speckled Wood on cherry foliage.
Kentle Wood, Daventry. 25 September, 2015

Butterflies were still on the wing, with the occasional Red Admiral providing a brilliant splash of colour, but most were relatively drab Speckled Woods, as shown in the photograph.

The nymph of Palomena prasina.
Kentle Wood, Daventry. 25 September, 2015

Also on oak was the nymph of the Green Shieldbug, Palomena prasina. This bug has featured in my blogs before and I can find little new to say about it. This specimen will just have time for a final moult and then, in preparation for winter, it will assume brown colours and probably creep under dead leaves until enticed out by spring sunshine.

Silk-button galls on oak. Kentle Wood, Daventry.
25 September, 2015

Galls were becoming increasingly evident on the oaks. This very common species is the Silk-button Gall, induced by the wasp, Neuroterus numismalis. A single leaf can bear dozens of these galls.

Artichoke Gall on oak at Kentle Wood,  Daventry.
25 September, 2015

Rather more striking was this Artichoke Gall, sometimes called the Hop Gall. Again it is the work of a wasp, this time Andricus foecundatrix.  In this case chemically-induced distortion has caused a bud to become completely misshapen. Although common, it is the first record for Kentle Wood. 






I had set out with limited aims, the main object being a relaxing walk. In fact several new species were recorded and I arrived home well pleased.