Galls: Pemphigus spyrothecae

17 Monday Jul 2023

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aphids on Poplar, British aphids, gall, gall-causing aphid, galls on Poplar, Pemphigus spyrothecae, Poplar

During our recent wet and windy weather I’ve taken to leaving my good camera at home, going out in wet weather gear with just my point-and-shoot camera tucked in a jacket pocket. As that camera is really only good for macro shots, I’ve been forced to look at things more closely – no bad thing, and, given the frequent heavy showers, I’ve been spending more time than usual sheltering under trees. And that, of course, means I’ve been looking at trunks and branches and leaves, which is how I came to notice these odd swellings on a Poplar tree in a local park. The aphid Pemphigus spyrothecae causes the leaf petiole to twist two or three times, forming a chamber in which the aphid’s larvae can develop. I didn’t open any of the galls but, if you want to see images of what’s inside, and read more about the life cycle of these aphids, the Influential Points website is the place to go.

230717 Pemphigus spyrothecae galls

Cocoon

08 Saturday Jul 2023

Posted by sconzani in insects, trees

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Aproceros leucopoda, Elm zigzag sawfly, Elm zigzag sawfly cocoon, insect cocoon, leaf damage by Elm zigzag sawfly larvae, Wych elm, Wych elm leaves

At this time of year, whenever I spot a Wych elm tree, I spend a bit of time staring at the leaves. I look for two things in particular: the first is to see if I can spot any White-letter hairstreak butterflies flitting around, usually at the top of the tree but also lower down; and the second is to see if anything has been nibbling at the leaves. My searching paid off last week when I spotted the distinctive signs of leaf damage caused by the larvae of the Elm zigzag sawfly (Aproceros leucopoda), not necessarily a good thing as this is an invasive species, which I found new to Wales in October 2021 (Zorro comes to Wales) and which is now slowly spreading westwards. But, more interestingly in this particular case, I found one of the cocoons the larvae pupate in, a very delicate, woven-silk structure (you can see an occupied cocoon on the Forest Research website). This one was empty so I guess that’s one more adult sawfly helping to spread the species further.

230708 elm zigzag sawfly cocoon

Leafmines: Eriocrania unimaculella

22 Monday May 2023

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British leafminers, British moths, Eriocrania unimaculella, leaf-mining moths, leafmine, leafmine on Birch, moth leafmines

The moth formerly known as Heringocrania unimaculella, now known as Eriocrania unimaculella – either way a tongue twister! – spends its larval stage developing within the leaves of Birch trees. And it poohs … a lot … pooh that Rob Edmunds, expert from the British Leafminers website, describes as ‘long strands of spaghetti’. There are several Eriocrania species that can be difficult to identify but Rob produced an excellent well-illustrated guide explaining how to separate them in his March 2018 newsletter (click to access). The adult moth is a tiny golden critter, which you can see on the UK Moths website.

230522 eriocrania unimaculella on birch

Leafmines: Coleophora serratella

15 Monday May 2023

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British leafminers, British moths, case-bearing moth larva, Coleophora serratella, Common case-bearer, leafminers on Birch, moth larvae

I’ve been checking Birch trees since their green leaves first started to unfold, prompted by a post I’d seen by Rob Edmunds (@leafminerman on Twitter) of the British Leafminers website to check for the small holes created by the feeding of the tiny Common case-bearer moth, Coleophora serratella. Finally, last Tuesday, I found some on a tree in Cardiff’s Grangemoor Park.

And, luckily, the little case-bearing larva was still in situ, initially checking out some silky seedhead fibres that had lodged on the end of its leaf, then retreating to the patch that marked where it had been feeding and resumed munching. You can read more about this beauty on the British Leafminers website and see the adult moth on the UK Moths website.

Leafmines: Coleophora lutipennella

01 Monday May 2023

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British moths, case-bearing larvae, Case-bearing moth, Coleophora, Coleophora lutipennella, Common oak case-bearer, moth larvae on Oak

It’s often the way that, while looking for one thing, I find another. In this case, I was checking for eggs or larvae on the newly opening buds and flowers of an Oak tree where I’ve previously seen Purple hairstreak butterflies. No luck with those but I did find this …

230501 Coleophora lutipennella (1)

It’s the larva of the Common oak case-bearer moth (Coleophora lutipennella) – you can see the pretty little adult moth on the UK Moths website here. These case-bearing moths remind me a bit of snails, spending their larval stage in a home they carry around with them, though the moths don’t grow their own – they weave theirs from bits of vegetation and silk. In the photo below, you can see the larva poking its head out from the bottom of its case.

230501 Coleophora lutipennella (2)

It can be difficult to distinguish between the larvae of two very similar case-bearing moths, this one and Coleophora flavipennella. I had my find confirmed by expert Rob Edmunds, who manages the British Leafminers website. The difference between the two cases is minor but fascinating, the presence or not of a small hump of leaf tissue built in to the case – there’s an explanation and some excellent photos on the website’s June 2004 newsletter.

New fungus: Linospora saligna

17 Friday Mar 2023

Posted by sconzani in fungi, trees

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British fungi, fungi on Salix leaves, fungi on willow leaves, fungus on leaf, Linospora saligna

Inspired by Gwent birder and naturalist Lee Gregory’s recent (3 March) first record for Wales of the fungus Linospora saligna, which looks like small dark speckles on dead Salix leaves, I went searching last Saturday morning in areas where I knew Willow trees grow. And I was a little surprised at how easy they were to find. I spotted the fungus at two locations along the path around Cardiff’s Grangemoor Park, and I’ve also since found it under Salix trees near Cardiff Bay’s Barrage. Although Lee’s record was a Welsh first and the NBN Atlas shows very few confirmed records for the rest of Britain, this is obviously another instance where a species is under-recorded, presumably because no one knows to look for it. I’m aware that Lee has already found several further records, and I will certainly continue to check for these speckled leaves wherever I see Willow trees.

230317 Linospora saligna

Alder flowers

12 Sunday Mar 2023

Posted by sconzani in flowers, trees

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Alder, Alder flowers, female Alder flowers, tree flowers

It’s almost two months to the day since I blogged about the first Hazel I’d seen with both the male and female flowers open (Flowers and catkins, 15 January). Perhaps I’ve been remiss in looking for these, but yesterday I spotted my first Alder tree where both types of flowers had opened. The reproductive systems of the two plants are remarkably similar, both with long dangling pollen-shedding male catkins and much smaller pink anemone-like female flowers, except that the female Hazel flowers develop into a nut and the female Alder into a cone. It’s the female flowers that I find particularly eye-catching.

230312 alder female flowers

Fit to bursting

05 Sunday Mar 2023

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male yew flowers, tree flowers, Yew, Yew tree flowers

I was checking this Yew tree for galls – found none – but it was absolutely covered in flower buds that were almost literally about to burst open. A few more days and this male tree will be spreading a sea of yellow pollen all around anytime the wind blows or someone brushes against its branches. How do I know it’s a male tree? Well, in a previous post, Flowering Yew trees from way back in March 2016, I blogged about Yew flowers so, if you want to know more about these fascinating trees, just click on that link.

230305 yew flowers

End of winter wild flowers

26 Sunday Feb 2023

Posted by sconzani in flowers, trees, wildflowers, winter

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British wildflowers, catkins, tree flowers, winter colour, winter flowers

As another winter draws to a close, I thought I would document the plant and tree flowers currently in bloom in my little bit of south Wales.

Galls: Phytoptus avellanae

20 Monday Feb 2023

Posted by sconzani in insects, trees

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British galls, bud galls, gall mites, gall-causing mites, galls on Hazel, Hazel, mite galls, mites, Phytoptus avellanae

These are my latest gall finds, caused by the mite species Phytoptus avellanae, shown here on Hazel (Corylus avellana) though they can also affect the buds of Filbert (Corylus maxima). The feeding of the mites on the plant cells within the buds causes those buds to swell and multiply. You can see a comparison in my photo below, the mite-infected gall bud on the left, the normal bud on the right.

230220 gall Phytoptus avellanae (1)

The mites that cause these galls are tiny, so rarely seen, but the Dutch Bladmineerders website has some excellent photos showing them in minute detail. As with so many galls, they are thought to be widespread in Britain but are not well recorded. So, if you’re out and about enjoying a spring walk and spot some Hazel, do please cast an eye over the buds, and record any galls you see. Citizen scientists really do make a difference to our knowledge of the natural world around us.

230220 gall Phytoptus avellanae (2)