Probably… some interesting spiders (Part II)

Before I get going, a cautionary note on getting over excited about interesting looking spiders… In my previous blog post, I shared a picture of an ‘almost’ mature male Araniella sp which was orangey-red coloured and looked like a credible candidate for the scarce Araniella displicata. My friend, and local spider expert, David Carr, found a similar one on Wanstead Flats a couple of weeks before mine, took it home to let it mature/moult and examined it. It turns out it was ‘just’ a reddish Araniella opisthographa (one of the common ‘Cucumber spiders’).

So, with that warning as a caveat… read on (no detailed genital spider identification here so everything below is simply the art of the possible; probable at best).

David also told me about a small colony of the nationally scarce jumping spider, Salticus zebraneus that he had found and confirmed from one of the copses on Wanstead Flats. On my fourth attempt to find one, and when a rare beam of sun lit up a tall tree stump I found a small Salticus moving in and out of the woody crevices. From the size, markings, and habitat, it is likely (but not definite) that this is Salticus zebraneus. Note that their bigger bolder cousins, like Salticus scenicus are commonly found on houses etc (Salticus sp is common in my garden).

Possible Salticus zebraneus – male

In my last post, I shared a strong candidate for Philodromus rufus – a spider we know is present on Wanstead Flats. Well, here is another very strong candidate but this time for the even rarer Philodromus buxi. This was beaten from Oak. The colouration, the markings on the legs, the fact that this species has been found here before all make this is possible, but obviously not confirmable without Get Det, so I have dutifully submitted it on iRecord as Philodromus sp and added the cheeky ‘candidate for P. buxi‘ in the comments.

Philodromus sp (likely P. buxi) – f

A first fly for London… nearly

Look at this lovely fly!

You could almost dive into that swimming pool of aquamarine/turquoise, its colour is so deep and inviting. Long legs, great markings. Just all round stunner!

And, I found it on my garden shed.

As flies go, it wasn’t too tricky to identify. It is a pretty big member of the Dolichopodidae family as a start and I believe the biggest in the UK.

An expert informed me that it can be found inland near “algal dominated leaks”. I’m kind of hoping there are no algal dominated leaks near my house and shed, but hey.

I checked NBN Atlas and there were a lot of records, mostly around the coast, but none in London. I love the idea of finding a London first record on my shed. In reality, it probably isn’t a first for London and iRecord shows that there are a couple of other records, but it clearly isn’t really a common find locally.

Apparently this poor fly species came close to losing its name due to some scientific mix-up. I hope it gets to keep it as I think Liancalus virens is pretty cool and suits it.

A turquoise metallic jewel and another highlight for my lockdown list.

Liancalus virens

Nature diary of a Nascent Pan-species Lister: 6 June 2020 (Fishers Green)

Got up very early on Saturday morning with a target of Nightingale, but was not successful. This is now multiple years in a row where I have tried, unsuccessfully, to hear Nightingale sing in London.

Highlights were my first calling Cuckoo for the year, views of singing Garden Warbler (one of six warbler species) and seeing the very young Black-headed Gull chicks on the Tern rafts (along with Common Tern also on nests).

Fishers Green is a lovely part of the Lee Valley water and woodland complex. I walked all around the Electricity Sub-station and some of the adjacent water bodies. A general observation was the amount of Dogwood (Cornus sanguinea) present; it really was everywhere.

I had a few plant galls of interest including my first ‘Sputnik gall’ for the year on Rose caused by the wasp, Diplolepis nervosa; they really are fantastic galls.

Sputnik gall (Diplolepis nervosa)

I recorded my first Italian Alder (Alnus cordata) – a non-native tree with noticeably more pointed leaves than our native alder – and the galls on it caused by mites, Acalitus brevitarsus and, seemingly, the angle gall Aceria nalepai (although the underside was a little confusing). This latter find is of real interest as A. nalepai is not recognised as causing galls on this particular host and I may return to collect some specimens for further examination.

Possibly two different mite galls on Italian Alder (Alnus cordata)

Other finds of note included:

Psyllopsis fraxini (agg) – an hemipteran causer of galls on Ash

A caddisfly (Athripsodes cinereus)

The Vapourer moth being its ridiculously showy self (Orgyia antiqua)

Nature diary of a nascent pan-species lister: 8 May 2020

A hot day in lockdown and my daily exercise took me on a quick circuit of some of Wanstead Flats. I only paused for any length of time around the Brick Pit Copse where I listened to, and eventually saw, a singing Garden Warbler (Sylvia borin) which had been found earlier in the day by N. Croft; our first locally for the year.

On the rest of my walk, I only stopped briefly to photograph a few invertebrates with my phone. The list below is snapshot of the things I took time to observe; species I specifically identified and recorded. I didn’t make too many attempts with flies (although I did iRecord Lucilia sp – a greenbottle) or one or two other invertebrate groupings, and there are no plants recorded here (although I did spend a bit of time checking the leaves of Quercus (oak), Acer (maples), Prunus (blackthorn, cherry etc). So, 81 species identified and recorded – not too shabby for a relatively brisk walk.

Selected birds: 40
I recorded 40 species of bird on my walk. The Garden Warbler was the obvious highlight, followed by an unusually showy Lesser Whitethroat.

Blurry shot of Garden Warbler

Accipiter nisus (Eurasian Sparrowhawk) – Only raptor seen on walk.

Alauda arvensis (Skylark) – only heard a couple of males singing.

Apus apus (Common Swift) – the breeding birds have been back a few days now.

Sylvia atricapilla (Blackcap) – seemingly everywhere.

Sylvia borin (Garden Warbler) – one singing.

Sylvia communis (Common Whitethroat) – also noticeably abundant this year.

Sylvia curraca (Lesser Whitethroat) – At least one, probably two singing.

Etc – 33 species of other bird commonly recorded locally also seen.

Lesser Whitethroat

Coleoptera – beetles: 7
I recorded seven species of beetle on my walk, three of which were lifers (remember I am a pan-species newbie) and three more were firsts for the year:

Andrion regensteinense (A broad-nosed weevil) – life first. Found on Broom.

Cantharis rustica (A soldier beetle) – first for year. Saw a couple.

Harpalus rufipes (Strawberry seed beetle) – life first (I’ve never recorded before, anyhow).

Malachius bipustulatus (Malachite beetle) – first for year.

Perapion violeceum (A weevil) – life first and possibly first record locally.

Propylea quattuordecimpunctata (14-spot ladybird) – possibly the most frequently seen ladybird at the moment locally.

Prosternon tessellatum (Chequered click beetle) – first click beetle I have seen this year. A few around.

Perapion violeceum – a rather tiny weevil

Hemiptera – true bugs: 3
Three species recorded with one new for the year. A bit poorer than I might have hoped for the bugs, to be honest.

Dryophilocoris flavoquadrimaculatus – Seemingly common in the local area. A small yellow and black flower bug.

Palomena prasina (common green shieldbug) – first for year for this shield bug.

Trioza remota – a tiny psyllid bug which galls oak leaves – the nymph resides in a depression on the underside of the leaf.

Hymenoptera – bees and wasps etc: 5
Four of the five recorded were identified by galls they cause. Other hymenoperans were on the wing, but few long enough for me to photograph and ID.

Andrena sp (likely ovatula) – very active pollinating in Broom.

Andricus curvator f. sexual – Causes distinctive swellings and twists on oak leaves. Very common locally.

Biorhiza pallida (Oak Apples Gall) – This wasp-caused gall is very common and one of the earliest to be seen in the season.

Neuroterus numismalis f. sexual (Oak blister gall / Silk button gall) – First for the year for me of this subtle gall.

Neuroterus quercusbaccarum f. sexual – seen many currant galls on oak catkins and leaves.

Blister gall on oak caused by sexual generation of Neuroterus numismalis wasp

Lepidoptera – moths and butterflies: 11
Three life-first moths for me, with the hemlock moth (Agonopterix alstroemeriana) being a particular highlight.

Aglais io (Peacock) – saw at least three.

Agonopterix alstromeriana (Hemlock moth) – a lifer for me. Found on Blackthorn.

Anthocharis cardamines (Orange Tip) – several seen.

Celastrina argiolus (Holly blue) – very common at the moment.

Erannis defoliaria (Mottled umber) – a caterpillar and second time I have seen this species in larval form in a matter of weeks.

Eupsilia transversa (Satellite moth) – a black caterpillar I’ve not recorded before.

Lycaena phlaeas (Small Copper) – abundant at the moment.

Pararge aegeria (Speckled wood) – several seen.

Pieris rapae (Small White) – several seen.

Polyommatus icarus (Common blue) – First for year for me with a specimen on Wanstead Flats and in my garden.

Syndemis musculana – another new moth for me. This tortrix was on Hawthorn.

Syndemis musculana

Selected Acari – mites: 10
All identified through the galls they cause on plants.

Aceria cerrea – This isn’t recognised on iRecord or much literature on British gall-causing mites as it was only recently refound in the UK. Causes galls on turkey oak.

Aceria macrochela – first for year. Causer of pustule growths along veins of field maple leaves.

Eriophyes prunispinosae/similis – first for year. Causer of pustule galls along leaf margin of blackthorn.

Etc – seven more mite-caused galls were identified, but all were galls I have recorded frequently elsewhere this year.

Erinea patch on underside of Quercus cerris caused by Aceria cerrea

Aranae – spiders: 4
Four species actively recorded.

Mangora acalypha (A cricket bat spider) – First for year for me.

Pardosa sp. (A wolf spider) – Found on bramble.

Pisaura mirabilis (Nursery web spider) – Found on buttercup.

Xysticus sp. (A crab spider) – Found on buttercup.

Pisaura mirabilis – the nursery web spider

Aceria ilicis: same, same, but different

Sometimes I am too accepting of things which should be challenged and investigated.

I regularly look at Holm Oak (Quercus ilex) leaves and notice the felt galls caused by the mite, Aceria ilicis. But someone on a social media gall group made me question more deeply what I have noticed before: we use the name Aceria ilicis to cover two quite different types of galls.

Type 1: the pimple gall

Distinct raised bumps showing on upper side of leaf

The upperside of the leaf shows distinct raised bumps or pimples with corresponding cavities on the underside filled with rusty brown erinea (hairy patches or felt).

Underside showing the rusty brown patches corresponding to the bumps on the upperside

When put under the microscope, these patches show themselves to be very dense patches of rusty brown, mostly tightly curled ‘hairs’.

Two patches filling cavities either side of central leaf vein

Under greater magnification

Type 2: the felty patch gall

No distinct pimples on upperside

In ‘type 2’, the upperside of the afflicted leaf may show some general bulging, but there are no distinct ‘pimples’ as with ‘type 1’.

The underside is comprehensively covered by darker brown erinea patches

Unlike in ‘type 1’, ‘type 2’ galls appear to be have darker brown erinea and to be quite extensively covered by felt patches.

Sometimes extensively filling the sections between veins

When looked at under greater magnification, the erineum itself appears slightly different.

Under greater magnification

The erineum is not only a different colour, but it appears to be growing less densely than in ‘type 1’ examples and the ‘hairs’ are less likely to be tightly curled.

Conclusions?

Without detailed study of the mites themselves – beyond my powers and powers of my microscope, I doubt a conclusion can be made.

However, I am not convinced by the argument that ‘type 2’ merely displays more mature and extensive galling. Even discounting differences in colour of the erinea patches, the lack of pimples in ‘type 2’ seems odd.

Could ‘type 1’ and ‘type 2’ be caused by different species of mite? Possibly.

One final interesting observation is that all the photos above, of ‘type 1’ and ‘type 2’ galls were taken from two leaves growing on the same tree host.