Tag Archives: galls

302/366 Gone galling, again

28 Wednesday Oct 2020

Posted by in autumn, insects, leaves, trees

≈ 1 Comment

Tags

, , , , , , ,

October is a good month to check out life on leaves (and I’ll be writing some posts about the various leaf mines I’ve been finding) but today I want to show you a couple of gall species that are new to me. The first is quite common and easy to find, the second perhaps less so.

The first species is Aceria macrochela, a microscopic mite that spends its larval life in these tiny bumps on the leaves of Field maple (Acer campestre). You can read more about them and see more images on the mighty Nature Spot website.

And the second is also a mite, this one called Stenacis euonymi, whose larvae make their homes in the rolled-up edges of leaves on Spindle (Euonymus europaeus). If you have trouble with tree identification, as I often do, this is a good time to look for these as the gloriously obvious fruit of the Spindle are easy to spot.

201028 Stenacis euonymi (1)

Looking on the NBN (Nature Biodiversity Network) Atlas I see there are currently only 112 UK records for this species (113 including mine, which doesn’t show yet) but that’s probably due to it being under-recorded, so if you spot these, please do record your sighting.

174/366 Mitey galls

22 Monday Jun 2020

Posted by in insects, leaves, nature, trees

≈ Leave a comment

Tags

, , , , ,

When walking along a narrow path between fields last week, I turned to face into the neighbouring hedgerow so that two other walkers could safely pass behind me. In so doing, I noticed these galls, which I think are Aceria campestricola (also known as Aceria ulmicola).

These growths betray the presence of the hundreds, perhaps thousands of the tiny mites that have caused these galls to form.

These particular galls can only be found on specific elm species, which in Britain include English elm and Small-leaved elm.

137/366 Bedeguar gall wasp

16 Saturday May 2020

Posted by in insects, nature

≈ 7 Comments

Tags

, , , , , , ,

You might remember that, a few months ago, I posted about the (supposedly) empty galls of the Bedeguar gall wasp I’d found during a wet walk at Cosmeston Lakes Country Park (Empty pincushions, January 2020). A week or so after writing that post, I was back at Cosmeston and remembered to harvest one of the galls, which has ever since been sitting in a sealed jar on my kitchen windowsill.

Although the many holes in the gall made me think that all of its inhabitants had already hatched, I decided to wait and see if anything else appeared. Two days ago I noticed movement in the jar and, taking a closer look, found two different species of wasp had emerged.

200516 diplolepis rosae (1)

This is one of them, and I’m 99% certain this is the gall causer itself, the Bedeguar gall wasp, Diplolepis rosae, the offspring of the wasp that caused the gall to form in the first place. These wasps are so tiny – just 3-4 mm long – that most of us don’t usually see them so I was very pleased to have this one emerge from its gall.

200516 diplolepis rosae (2)

There is a bit of a story attached to the second wasp that emerged, and I am currently awaiting confirmation of its identity. As soon as I know more, I’ll write it up in a further post.

31/366 Empty pincushions

31 Friday Jan 2020

Posted by in insects, nature, plants

≈ 5 Comments

Tags

, , , , , ,

Robin’s pincushions are the amazing gall structures created on Dog roses by the larvae of Diplolepis rosae, the Bedeguar gall wasp.

200131 Robins pincushions (1)

I’ve seen the bright red galls many times during the summer months but I’ve not looked for them in the winter, so it was interesting today to find these and to see the very obvious holes where the adult wasps have hatched out. If it hadn’t been raining, I would have broken one off and brought it home for a closer look inside … maybe next week.

200131 Robins pincushions (2)

252/365 Alder tongue

09 Monday Sep 2019

Posted by in 365DaysWildin2019, fungi, nature, trees

≈ 2 Comments

Tags

, , , , , ,

While sneaking up on a juvenile Green woodpecker at Cosmeston, I spotted these lovely examples of Alder tongue (Taphrina alni).

190909 alder tongue (1)

I’ve covered these intriguing galls in a previous blog post so, just briefly, they’re the result of a fungus that chemically alters its host. One of Nature’s oddities!

190909 alder tongue (2)

155/365 A good crop of apples

04 Tuesday Jun 2019

Posted by in 365DaysWildin2019, insects, nature, trees

≈ 2 Comments

Tags

, , , , , ,

190604 oak apples (1)

But you wouldn’t want to eat them! These are oak apples, the incredible creations of the larvae of the wasp Biorhiza pallida. By a magical process of chemical interaction, the larvae force the buds of the Pedunculate Oak to change and produce these galls, which the larvae call home until they’re ready to develop into their next stage of life.

A couple of the young oak trees in some fields near where I live are proving particularly attractive to these wasps so they have a bounty of apples growing on them this year. Yet another of Nature’s miracles!

190604 oak apples (4)

Andricus kollari, maybe

14 Saturday Apr 2018

Posted by in insects, nature, trees

≈ 2 Comments

Tags

, , , , , , ,

180414 Andricus kollari (3)

If you’re a regular around here, you may recall that in August 2017, I posted a mini-series of posts about some of the galls you can find on Oak trees, which included the Oak Marble gall (see the post here). You might also remember that in late October, I was excited to discover a creature had hatched out of one of my galls and I initially thought it was the gall causer, a minute wasp called Andricus kollari. It was not – turns out it was one of the 29 other species of hymenoptera (bees, wasp, ants and sawflies) that can also be found living in an Oak marble gall (more on that here) (and I never did identify it).

Well, this time, maybe, just maybe, I have seen the gall-causing wasp itself, A. kollari. A while ago, while out walking, I found a small Oak sapling that was absolutely covered in marble galls and, when I found one that had no holes in it, I couldn’t resist bringing it home. The tiny wasp you see in these photos recently hatched out of this gall and the size of the hole it made, plus comparisons with online photos, has led me to think that this time I may have seen the gall causer. I couldn’t be one hundred percent certain of my identification without killing the wasp and getting an expert to check it but I didn’t want to do that. And, of course, I could be totally wrong yet again. In the meantime, the wasp has been returned to the area where I found it so, weather permitting, it can continue its life cycle.

A mini challenge

09 Monday Oct 2017

Posted by in insects, nature

≈ 8 Comments

Tags

, , , , , , ,

On Friday I went for a wander around one of my favourite local haunts, Cosmeston Lakes Country Park and, while there, I set myself a little challenge. How many critters could I find in one small area, perhaps no more than 2 metres square?

171008 mini challenge

My challenge wasn’t pre-planned: I had seen very little at this point on my walk and was thinking to myself that this was due to autumn and the cooler weather but, when I saw a Speckled wood butterfly at this particular spot – a bank covered with shrubs and small trees – I started wondering how much more there was that I simply wasn’t seeing. So, I stopped and looked harder. There was no poking under grasses or bushes, no sweeping or brushing to encourage movement, just focussing my eyes and ears to really see and hear.

There were, in fact, three Speckled woods – I just hadn’t noticed the other two, plus three different species of spider (the Garden spider was lunching on another critter but it was partly consumed and too tiny to identify), one hoverfly, three species of flies, a gall on Bramble that would’ve been home to the larvae of the tiny gall wasp Diastrophus rubi, and a leaf mine, made by the larva of some unidentified mini-beast. And I’m absolutely sure I didn’t spot everything!

More galls, part 2

04 Wednesday Oct 2017

Posted by in insects, nature, plants

≈ 1 Comment

Tags

, , , ,

Following on from yesterday’s More galls, part 1 …

This second gall’s host is not a tree, it’s a thistle, Creeping thistle (Cirsium cardui) to be precise, and the gorgeous little fly that causes the gall is Urophora cardui, the Thistle gall fly, a member of the Tephritidae or fruit fly family. Interestingly, this fly has been introduced into Canada, from populations originating in Austria, Germany, France and Finland, in an attempt to control Creeping thistle, which is there called Canada thistle and is regarded as an invasive weed. The gall production initiated by the flies disrupts the development of flowers and also significantly reduces the vigour of the thistle by diverting nutrients into the gall.

In Britain, the adult Urophora cardui fly can be seen between May and September when, after mating, it lays its eggs on a nearby Creeping thistle. The larvae burrow into the thistle’s stem, often causing a single gall to develop to house several larvae. The larvae also pupate inside the gall, emerging as flies between June and October. I’ll be checking all the Creeping thistles I see for a glimpse of them.