Galls: Phytoptus avellanae

20 Monday Feb 2023

Tags

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)

161/366 Mite galls on Lime leaves

09 Tuesday Jun 2020

Posted by sconzani in insects, lichen, nature, trees

≈ 3 Comments

Tags

Eriophyes mites, gall mites, gall-causing mites, galls on Lime leaves, lime galls, Lime trees, mites

These stopped me in my tracks!

200609 lime gall mites (1)

I’d enjoyed a nice amble around a local park and was on my way home when I spotted these incredible galls and just had to stop for some photos. The galls are caused by tiny mites that spend the cool winter months huddling in cracks on the tree’s bark, then head out on to the leaves when they sprout in the springtime.

200609 lime gall mites (2)

The mites are leaf-sap suckers, and their sap sucking causes a chemical reaction in the leaf, which in turn prompts the leaf to produce these small, conical, hollow growths. The mites are incredibly tiny – less than 0.2mm long apparently – so they’re almost never seen, whereas their cosy gall homes can grow to 8mm long and, when they’re as bright as these ones were, are very obvious on the leaves.

I’m not sure which mites these are as I’m not sure which tree species this is. One mite species, Eriophyes tiliae, is the gall causer on Large-leaved lime trees (Tilia platyphyllos), Common limes (Tilia x europaea) and some hybrid Lime species, and another mite, Eriophyes lateannulatus, causes very similar galls on Small-leaved Limes (Tilia cordata) and hybrid Limes.

200609 lime gall mites (5)