Eye on Nature: Your notes and queries

I saw what looked like a pea-sized green spider with reddish markings. Is it in fact a louse or a tic, and is it dangerous?
Ruth Marshall
Raheen Wood, Co Clare

My daughter photographed a white crab spider on a white rose in the garden.
Suzanne Mac Dermot
Cobh, Co Cork

From the photographs both of you sent, they are the flower spider 'Misumena vatia', one of the crab spiders. They are no threat to humans.

My daughter, Lara, found some hard sacs in the leaves of a weeping willow. Each contained a tiny caterpillar.
Keith Pickett
Palmerstown, Dublin

The growths are caused by the gall midge 'Iteomyia capreae', which lays its eggs on willow leaves. The larvae appear in May and June, feed for the summer, then drop off to pupate in the ground.

I photographed a hummingbird-like creature in my garden. What is it?
Bren Hick
Shankill, Co Dublin

A hummingbird hawkmoth, an immigrant from southern Europe.

Michael Viney welcomes observations at Thallabawn, Louisburgh, Co Mayo, or by email at viney@anu.ie. Please include a postal address