and I spent almost the whole day doing some serious gardening. We saw lots of
invertebrates, mostly on the wing including assorted butterflies, assorted bees and
queen wasps, and some spiders too. The most notable insect was a beautiful reddish-
brown Bee Fly, the first I have seen this year. He (? How do you sex a Bee Fly?) was
very close to our natural Primrose/Cowslip hybrid Primula x polyantha both parents
of which I think are favourites of Bee Flies. The spell of seriously warm weather has
enabled the insects to come out and move around: some have hibernated as adults,
such as the Peacock butterfly and the queen wasps and bumble bees, while some others
have recently emerged from pupation, like the St Marks Flies and the Bee Fly (thank
you, Peter Harvey, for some help here).
Early in May we went to count the local colony of Yellow Vetchling Lathyrus aphaca.
It is in a field that is part of Belhus Woods Country Park, and the numbers vary from
about 250 to 10,000, but this is not unusual for an annual. As we walked through the
grassy meadow we noticed Goat's-beard with flower buds ready to burst open, but
actually they were all swollen and the outer green bracts enclosed a mass of violet-
black fungal spores due to infection by a Smut that rejoices in the name of Ustilago
tragopogonis-pratensis. Having since seen Goat's-beard Tragopogon pratensis in lots
of other places, they all seem normal, so what had happened to these ones that the
flowers were all destroyed? Oh, and yes, the total of our Yellow Vetchling count was
about 450.
A couple of days later Peter Harvey and I met at a field in Thurrock to have a look at its
plants and invertebrates. What I had assumed would all be done in 2 hours, actually
took us 4 1/2 hours, but with considerable interest for both of us. The field, threatened
with housing development, was original Thames Terraces, so the soil was not real soil
over much of the area, but sand and pebbles. Special plants live there, ones associated
with this sort of area, and invertebrates to match, though Peter expressed displeasure
with the wind, which prevented some of his special ones from flying about. There
were hundreds of plants of Purple Gromwell Lithospermum purpureocaeruleum, (see
Plate 2) but sadly they must have been garden escapes as this plant is not native in this
part of Britain, though they clearly love this field. I showed Peter some of the special
plants, and I watched in amazement as Peter chased tiny things on the ground with his
pooter. It meant we were both crawling around on the ground, which must have
looked very amusing for passers-by! However, our efforts were rewarded amply by the
unexpected discovery of Meadow Saxifrage Saxifraga granulata (see Plate 1), now
rare in Essex, in full bloom in a number of places near Hawthorn trees where it was
protected slightly from the marauding rabbits. Peter was pleased to find the ground
bug Megalonotus praetextus around the base of its host plant Common Stork's-bill
Erodium cicutarium, the shield bug Sciocoris cursitans, flea beetles Longitarsus dorsalis
and Podagrica fuscipes and the mining bec Andrena labiata, all Nationally Scarce
species, as well as the Red Data Book ant Myrmica specioides, a species of warm
sparsely vegetated situations near the coast. Also found was the tiny jumping spider
Talavera aequipes, another very local species of sunny sparsely vegetated situations.
So we both had a good time, and got some useful records too.
6
Essex Field Club Newsletter No. 60, September 2009