Overscourt, 14 August 2024

Leader: Alvan White

Nine members gathered at the Overscourt car park. Once the dog walkers and their cars had thinned, we were all able to access parking. The day was overcast with occasional drizzle. Combined with the wet winter and spring this did not auger well for spotting wild life.

The walk visited the grasslands and secondary woodland on the east of the site and a large meadow on the west side. All the grasslands remained uncut and pristine.

The east side was notable for yellow Fleabane and pink Great Willowherb, both sides for Wild Carrot. The west side contained plants more typical of meadowland including Scabious species, Agrimony, and Vetch.

We discussed the red/black spot seen in the many Wild Carrot flower heads. Helena later confirmed the strategy. “Yes, this is a Wild Carrot flower head – an umbel composed of many tiny flowers. Plants in different families adopt this strategy of massing lots of little flowers together to look like one big showy one in order to attract pollinators, which then land and pollinate many little flowers at once as they crawl about on the flower head.

“The central flower of a carrot flower head is often (though not always) dark. This looks like a little beetle, so a passing flying male beetle thinks Aha! And zooms in to mate with it. Having discovered his error, he bumbles about, pollinates some flowers with pollen from his body, picks up more pollen … then flies off and makes the same mistake all over again! And thus pollinates more plants! Silly little beetle – clever plant!”

Both areas do contain large amounts of Blackthorn but there was no sign of Brown Hairstreak. Indeed there was very little butterfly life at all, limited to Speckled Wood and a single Small Copper.

However, moth numbers easily exceeded the butterflies. Highlights included the Maiden Blush, Pale Straw Pearl, Silver Y, and Shaded Broad-barr. In addition a colourful yellow and black Buff-tip caterpillar was found underneath a leaf on a young Sallow tree.

There was a distinct lack of orthoptera. However, sweep netting produced a Meadow Grasshopper, the virtual in line pronotal side keels (on the pronotum) causing it to be called Pseudochorthippus parallelus.

Also found was a nymphal stage of either Small or Long-winged Conehead, very difficult to separate as the wings are not developed in this young stage.

Plenty of grassland spiders were found by sweep netting, and identifications were later confirmed by experienced arachnologists. There were many highlights, including Furrow Orbweaver (Larinioides cornutus), Neottiura bimaculata, a brown ground crab spider in the genus Xysticus and a Metellina species.
Raft-type webs were observed, but they proved to belong to the Labryinth spider (Agelena labyrinthica). Their tubular retreats were hidden deep within the grass. A spider was captured and shown to the group. The chevrons on the back of the abdomen are key identification feature.

Although looking like ideal habitat for Wasp Spiders, none were found. I have yet to hear any reports from the Bristol area.

Many plant bugs were seen. The most colourful was a Red Spotted Plant Bug (Deraeocornis ruber).

An interesting find was the Snail Killer Fly (Limnia unguicornis), whose larvae are reported to feed on the European Amber Snail (Succinea putris).

Birds identified by sight and sound were Grey Heron, Bullfinch, Great Spotted Woodpecker and Stock Dove.

Despite the weather a wealth of invertebrate and plant life were discovered.

Alvan White